cssi/SciSciGPT-SciSciNet huggingface dataset:
Structural and functional delineation of aerobactin biosynthesis in hypervirulent Klebsiella pneumoniae

Aerobactin, a citryl-hydroxamate siderophore, is produced by a number of pathogenic Gram-negative bacteria to aid in iron assimilation. Interest in this well-known siderophore was reignited by recent investigations suggesting that it plays a key role in mediating the enhanced virulence of a hypervirulent pathotype of Klebsiella pneumoniae (hvKP). In contrast to classical opportunistic strains of K. pneumoniae, hvKP causes serious life-threatening infections in previously healthy individuals in the community. Multiple contemporary reports have confirmed fears that the convergence of multidrug-resistant and hvKP pathotypes has led to the evolution of a highly transmissible, drug-resistant, and virulent "super bug." Despite hvKP harboring four distinct siderophore operons, knocking out production of only aerobactin led to a significant attenuation of virulence. Herein, we continue our structural and functional studies on the biosynthesis of this crucial virulence factor. In vivo heterologous production and in vitro reconstitution of aerobactin biosynthesis from hvKP was carried out, demonstrating the specificity, stereoselectivity, and kinetic throughput of the complete pathway. Additionally, we present a steady-state kinetic analysis and the X-ray crystal structure of the second aerobactin synthetase IucC, as well as describe a surface entropy reduction strategy that was employed for structure determination. Finally, we show solution X-ray scattering data that support a unique dimeric quaternary structure for IucC. These new insights into aerobactin assembly will help inform potential antivirulence strategies and advance our understanding of siderophore biosynthesis.
3 Sustainable agriculture: An agroecological perspective

Publisher Summary Agriculture worldwide has been benefited from several decades of increasing yields and surplus production of many commodities. Present agricultural practices are pointed to as the principal area in which to begin the shift toward more sustainable food and agricultural systems. An agroecological approach simultaneously strives to improve crop yields, as well as understand the processes that permit the maintenance of those yields. The primary goal is to establish a means of determining the long-term sustainability of agricultural systems. The primary foundation of agroecology is the concept of the ecosystem, defined as a functional system of complementary relations between living organisms and their environment, delimited by arbitrarily chosen boundaries that in space and time appears to maintain a steady yet dynamic equilibrium. A well-developed, mature natural ecosystem is relatively stable, self-sustaining, and able to maintain productivity using energy inputs of solar radiation alone. In examining agricultural systems from an ecosystem perspective, one have a basis for looking beyond a primary focus on system outputs, and instead look at the complex set of biological, physical, and chemical interactions that determine the processes that permit to achieve and sustain those yields. An understanding of the chief characteristics of natural ecosystems, as well as the differences that are introduced once human manipulation of the system takes place for the purpose of agricultural production, can be an important step in an analysis of sustainability.
Sleep, cognition, and emotion: A developmental view.

In the course of the past century, developmentalists have learned a great deal about cognitive and emotional develop-ment of children from birth to adulthood (Cole et al., 2000). The vast majority of this research, however, has focused on the child’s development and behavior during daytime when the child is active and
Endometriosis: a comparison of associated disease histories.

We examined a subgroup of 43 women with endometriosis who reported family members affected by the disease. A matched group of female friend-controls (n = 43) was used for comparison, and reports of selected autoimmune diseases, infectious diseases, and allergic manifestations were compared. For this subset of women, there appeared to be a strong familial tendency to allergic manifestations. Vaginal yeast infections, a history of mononucleosis, eczema, hayfever, and food sensitivities were reported to occur much more frequently for these women. All statistical tests on these conditions were significant at the .05 level of probability or less.
CYTOCHROME P-450 FORM 4, A MAJOR DETERMINANT OF 2-AMINOANTHRACENE MUTAGENESIS

Reconstituted rabbit liver cytochrome P-450 form 4 activated the arylamine, 2-aminoanthracene (2AA), to a mutagen 8 to 15 times faster than three other forms tested. When post-mitochondrial supernatant fractions from control and 2,3,7,8-tetrachlorodibenzo-p-dioxin-treated adult and neonatal rabbits were assayed, 2AA activation occurred. This activity was located in the microsomal component and differences in cytochrome P-450 form 4 levels in these fractions correlated with differences in 2AA activation. These results suggest that tissue levels of form 4 are an important determinant of 2AA mutagenesis in the rabbit.
Thursday, September 27, 2018 1:05 PM–2:05 PM Lumbar Spine Surgery: What You Need to Know: 111. Fibular allograft as a salvage option in revision pedicle screw fixation

BACKGROUND CONTEXT In the setting of revision spine surgery for pseudoarthrosis, a variable amount of pedicle bone loss may be present. This is a result of screw loosening and subsequent screw track widening. Often the bone quality may be poor secondary to aging, malnutrition, previous infection and smoking. In these difficult cases, multiple techniques have been utilized to enhance the construct strength. Current options for revision pedicle screw fixation include cement augmented screw fixation and custom-made large diameter screws. PURPOSE The purpose of this study was to present the authors’ experience using fibular allograft in the setting of bone loss with loose pedicle screw revision. STUDY DESIGN/SETTING Retrospective. PATIENT SAMPLE A total of 10 patients. OUTCOME MEASURES CT scan lumbar spine ODI. METHODS In patients with extensive screw track dilation, fibular allograft was obtained and cut into small, longitudinal strips—approximately 3 mm in thickness. The length of each fibular allograft strut was trimmed to coincide with the length of the former screw, allowing for overhang. Allograft strut was inserted into the screw track along the wall. The screw was then advanced between the allograft, and after full insertion of the screw, the fibular allografts were then trimmed. RESULTS This technique was successfully used in 10 consecutive patients during revision lumbar spine surgeries for pseudoarthrosis. All patients had loose pedicle screws with significant bone loss around the screw tracks. Excellent purchase was achieved in all patients. CT scan at the last follow up showed incorporation of the fibular allograft and sound fusion in all patients except one. CONCLUSIONS Fibular allograft is a viable option in the setting of revision pedicle screw fixation and has several advantages when compared to currently available methods. It avoids the complications associated with cement augmented pedicle screws. In addition, it can be used impromptu, when other options are not immediately available. This technique can be employed without specialized instrumentation at significant cost savings when compared to custom made screws. Finally, this technique allows for biologic fixation at the screw-bone interface. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.
Pentablock Copolymer Micelle Nanoadjuvants Enhance Cytosolic Delivery of Antigen and Improve Vaccine Efficacy while Inducing Low Inflammation.

As the focus has shifted from traditional killed or live, attenuated vaccines toward subunit vaccines, improvements in vaccine safety have been confronted with low immunogenicity of protein antigens. This issue has been addressed by synthesizing and designing a wide variety of antigen carriers and adjuvants, such as Toll-like receptor agonists (e.g., MPLA, CpG). Studies have focused on optimizing adjuvants for improved cellular trafficking, cytosolic availability, and improved antigen presentation. In this work, we describe the design of novel amphiphilic pentablock copolymer (PBC) adjuvants that exhibit high biocompatibility and reversible pH- and temperature-sensitive micelle formation. We demonstrate improved humoral immunity in mice in response to single-dose immunization with PBC micelle adjuvants compared with soluble antigen alone. With the motive of exploring the mechanism of action of these PBC micelles, we studied intracellular trafficking of these PBC micelles with a model antigen and demonstra...
International Academy of Cytology Yokohama System for Reporting Breast Fine-Needle Aspiration Biopsy Cytopathology: A Review of Predictive Values and Risks of Malignancy.

Objective We aimed to assess the risk of malignancy (ROM) and predictive values in prior breast cytology studies as a basis for the new International Academy of Cytology (IAC) Yokohama system for reporting breast fine-needle aspiration biopsy (FNAB) cytology, which classifies cytologic diagnoses into 5 categories: (1) insufficient material, (2) benign, (3) atypical, (4) suspicious of malignancy, and (5) malignant. Study design Publications between January 1, 1997, and December 31, 2017, that studied the performance characteristics of FNAB from palpable and nonpalpable breast masses were identified through the PubMed database. Data for number of total cases and cases within each diagnostic category, if available, were collected. Performance characteristics, including absolute sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and ROM for each category were recorded or, when possible, calculated. Results The literature review resulted in a case cohort of 33,341 breast FNABs, drawn from 27 studies. Pooling these cases together, the ROM for insufficient material, benign, atypical, suspicious, and malignant were 30.3, 4.7, 51.5, 85.4, and 98.7%, respectively. The complete sensitivity and specificity were 96.3 and 98.8%, correspondingly. The PPV and NPV were 98.7 and 95.3%, correspondingly. The false-negative and false-positive rates were 3.7 and 1.0%, respectively. Conclusions This meta-analysis demonstrates that the diagnostic categories of the new IAC Yokohama System each carry an implied ROM, which increases from the benign to malignant categories. This study also shows the high sensitivity and specificity of FNAB for breast lesions.
A Review of Intrarenal Hemodynamics and Hydrodynamics

Publisher Summary This chapter discusses some of the fundamental aspects of the hydroynamics and hemodynamics of the kidney, focusing on its excretory function. In each normal human kidney, there are approximately one million glomerulotubular units in which the urine is formed. Urine is the resultant of three processes: (1) ultrafiltration at the glomerulus, (2) reabsorption of water and solutes from water, and (3) secretion of solutes into the tubules. The rate of filtration is determined by hydrostatic forces. An increase in reabsorption into the peritubular capillaries results in a decrease of the hydrostatic pressure in the intercellular labyrinth and interstitial spaces, and thereby leads to a greater rate of transport out of the tubule. This implies that the hydrostatic pressures in the intercellular spaces, in the proximal tubule, and in the peritubular capillaries are different.
Open Technique for Ivor Lewis Esophagectomy

For many years, surgical resection of the esophagus and subsequent reconstruction of enteral continuity was a formidable challenge for surgeons and patients alike. Since the first esophageal resection, much has been learned about the anatomical and physiological aspects of esophagectomy. One type of esophageal resection and reconstruction has been referred to as Ivor Lewis esophagectomy, after a British surgeon who utilized an abdominal incision and right thoracotomy to resect the cancer of the esophagus. Herein, we describe our modified approach with this technique.
PRINCIPAL SINGULAR VECTOR ANALYSIS FOR SEPARATING MOVING OBJECTS IN NOISY PERSPECTIVE IMAGES

Multi-target motion-shape-estimation(MSE) problem is, given a sequence of 2-D video images of multiple moving targets, to track the 3-D motion of the targets and reconstruct their 3-D shapes. When two noisy target images are close, the feature points (FPs) may be very much mixed, so they must be clustered such that the FPs of A are separated from those of B and the FPs may be mapped onto their correct objects. It is critical is to develop numerically robust and efficient clustering strategy. Our method hinges upon the numerical stability of the SVD factorization, especially the strong noise insusceptibility of the Principal Singular Vectors(PSV). The characteristics of PSVs have been carefully analyzed. It is found that PSVs have very high vigilance against corruption by various noises and distortions. Moreover, under certain dominance assumption, their behaviors may be described by an analytical formula. Simulations also strongly support the theoretical findings. In short, the PSVs can be very instrumental for separating moving objects in noisy perspective images and they may be applied to 3-D target recognition, navigation, and video and 3-D image coding.
The metabolic signature of T cells in rheumatoid arthritis.

Purpose of review Rheumatoid arthritis (RA) is a prototypic autoimmune disease manifesting as chronic inflammation of the synovium and leading to acceleration of cardiovascular disease and shortening of life expectancy. The basic defect causing autoimmunity has remained elusive, but recent insights have challenged the notion that autoantigen is the core driver. Recent findings Emerging data have added metabolic cues involved in the proper maintenance and activation of immune cells as pathogenic regulators. Specifically, studies have unveiled metabolic pathways that enforce T cell fate decisions promoting tissue inflammation; including T cell tissue invasiveness, T cell cytokine release, T cell-dependent macrophage activation and inflammatory T cell death. At the center of the metabolic abnormalities lies the mitochondria, which is consistently underperforming in RA T cells. The mitochondrial defect results at least partially from insufficient DNA repair and leads to lipid droplet accumulation, formation of invasive membrane ruffles, inflammasome activation and pyroptotic T cell death. Summary T cells in patients with RA, even naive T cells never having been involved in inflammatory lesions, have a unique metabolic signature and the changes in intracellular metabolites drive pathogenic T cell behavior. Recognizing the role of metabolic signals in cell fate decisions opens the possibility for immunomodulation long before the end stage synovial inflammation encountered in clinical practice.
Dorsal raphe dopamine neurons signal motivational salience dependent on internal and external states

The ability to recognize motivationally salient events and respond to them adaptively is critical for survival. Here we tested whether dopamine (DA) neurons in the dorsal raphe nucleus (DRN) contribute to this process. Population recordings of DRN^(DA) neurons during associative learning tasks showed that their activity dynamically tracks salience, developing excitation to both reward- and punishment-paired cues. The DRNDA response to reward-predicting cues was diminished after satiety, suggesting modulation by internal states. DRN^(DA) activity was also greater for unexpected outcomes than for expected outcomes. Two-photon imaging of DRN^(DA) neurons demonstrated that the majority of individual neurons developed activation to reward predicting cues but not to punishment-predicting cues, which was surprising and qualitatively distinct from the population results. Head-fixation during fear learning abolished the neural response to aversive cues, indicating modulation by behavioral context. Overall, these results suggest that DRN^(DA) neurons encode motivational salience, dependent on internal and external factors.
Model Predictive Control of Selective Vagal Nerve Stimulation for Regulating Cardiovascular System

Previous studies have proposed closed-loop methods to determine one of the vagal nerve stimulation (VNS) parameters based on the feedback of heart rate but never consider the blood pressure. This study develops a nonlinear model predictive controller (NMPC) for a multi-location VNS system, which controls heart rate (HR) and mean arterial pressure (MAP) by independently manipulating multiple stimulation parameters in three different locations. Pulsatile and non-pulsatile models of the integrated cardiovascular system and baroreflex regulation are developed to predict the dynamic response of the MAP and HR. The two models are compared and elicit similar dynamics. The NMPC algorithm incorporates the non-pulsatile model and is evaluated by the pulsatile model. Three set point tracking cases are presented and discussed. The performance of NMPC shows the feasibility and usefulness of the proposed control algorithm for the regulation of HR and MAP during multi-location VNS.
Variability in Human-Animal Interaction Research.

The field of Human-Animal Interaction (HAI) is plagued with mixed results. Some findings appear to indicate that interacting with a companion animal is beneficial for some aspect of human health and wellbeing, while other research outcomes are inconclusive or even indicate the opposite. The purpose of this paper is to take a closer look at this variability in research outcomes and to provide plausible explanations and potential remedies. Some of the reasons for mixed results are likely due to the wide variety of methodologies implemented, intermittent use of standardized measures and manualized protocols, variability in human and animal participants, and limited quantification of human-animal interactions or definitions of pet ownership. Variability in research outcomes is not unique to HAI and is, in fact, not uncommon in many more established fields such as psychology and medicine. However, the potential reasons for the variability may be linked to the unique nature of HAI in that, in its’ simplest form, it involves two complex organisms, a human and a companion animal, interacting in dynamic ways. We argue that this complexity makes research in this field particularly challenging and requires a broad spectrum of theoretical and methodological considerations to improve rigor while ensuring the validity and reliability of conclusions drawn from study results.
Preservice music teachers’ self-efficacy and concerns before and during student teaching:

The purpose of this study was to investigate the experiences and contextual factors that influenced preservice music teachers’ self-efficacy and concerns from pre-student teaching to student teachi...
Pregnancy and Neonatal Outcomes Among Deaf and Hard of Hearing Women: Results From Nationally Representative Data.

Abstract Background Although the literature suggests that women with disabilities are at increased risk for pregnancy complications and adverse birth outcomes, there are few population-based studies of pregnancy outcomes among deaf and hard of hearing (DHH) women in the United States. Objective To compare pregnancy complications and neonatal outcomes between deliveries to DHH and non-DHH women using national hospitalization discharge record data. Study Design We used the 2007–2016 Healthcare Cost and Utilization Project National Inpatient Sample to compare pregnancy complications and outcomes among deliveries to DHH women with deliveries to non-DHH women using bivariate and Poisson regressions, controlling for sociodemographic, hospital, and clinical characteristics. Results DHH women had an increased risk of adverse pregnancy outcomes and chronic medical conditions, including preexisting diabetes (relative risk [RR], 2.01; 95% confidence interval, 1.68–2.42; p Conclusions DHH women are at increased risk for adverse pregnancy, fetal, and neonatal outcomes, illuminating the need for awareness among obstetric and primary care providers as well as the need for systematic investigation of outcomes and evidence-based guidelines.
Genes, Culture, and History in Coevolution

This chapter summarizes the basics of the individual and collective coevolution of genetics and culture for Homo sapiens. It argues that the evolutionary process established statistical universal predilections for our human political nature in the areas of authority, equality, homophily, and altruism. The success of the coevolutionary paradigm has led to new theoretical models in the social sciences and sparked historians to reconceptualize the foundations of historical explanation. Peter Turchin’s cliodynamics has built upon these insights, asking historical questions that can be answered by deploying empirically based evidence and methods that test rival theories of change against one another through retrospective prediction, or retrodiction. Because Turchin’s approach works within the epistemology of naturalism, his historical method moves us closer to E.O. Wilson’s goal of consilience, which encourages humanists, scientists, and social scientists to “jump together” in the production of knowledge.
Copper and Silver

Sedimentary deposits of copper are common, contributing between 25 and 30 percent of the world’s production (Jacobsen 1975, table 1). Most of this amount, however, comes from one district, the Central African Copperbelt. Silver is almost always associated with the copper in these ores, and so will also be considered in this chapter. Also discussed are supergene deposits of copper and silver. Although of diminished economic importance today, they serve to illustrate the geochemical processes involved in ore-formation without some of the uncertainties associated with interpretations of the genesis of the larger deposits.
Real-Time Feature Matching for the Accurate Recovery of Augmented-Reality Display in Laparoscopic Videos

Augmented-Reality (AR) displays increase surgeon’s visual awareness of high-risk surgical targets (e.g., the location of a tumor) by accurately overlaying pre-operative radiological 3-D model onto the intra-operative laparoscopic video. Existing AR systems are not robust to sudden camera motion or prolonged occlusions, which can cause the loss of those anchor points tracked along the video sequence, and thus the loss of the AR display. In this paper, we present a novel AR system, integrated with a novel feature-matching method, to automatically recover the lost augmentation by predicting the image locations of the AR anchor image-points after sudden image changes. Extensive experiments on challenging surgical video data are presented that show the accuracy, speed, and robustness of our designs.
Discrete model of transition between order and static chaos in peptides and polymers

Biological function of a peptide or properties of a polymer material depend on chemical composition of a macromolecule and on its geometry. A mechanistic model is considered to investigate the factors changing a geometrically ordered macromolecule into a geometrically chaotic one, assuming no chemical change. 2 D and 3 D examples show how a small change in interaction between parts of a macromolecule can transform an ordered geometry of the (bio) polymer into a chaotic one. It is mathematically interesting that the systems obey the difference equations, which in the continuum limit lead to differential equations with well-behaving (non-chaotic) solutions, while in certain cases behavior of the difference equations seems to be chaotic.
Lady beetles (Coleoptera: Coccinellidae: Coccinellini) associated with Alaskan agricultural crops

Adult coccinellid abundance was monitored in agricultural areas of the Tanana and Matanuska—Susitna River Valleys of Alaska during 2004 and 2005. Thirteen species were collected in association with Alaskan agricultural crops. Of the species collected, Hippodamia quinquesignata quinquesignata (Kirby), Coccinella transversoguttata richardsoni Brown, and Hippodamia tredecimpunctata tibialis (Say) were by far the most abundant species, making up 51, 18, and 12%, respectively, of the individuals collected. Two new species, Coccinella septempunctata L. and Hippodamia convergens Guerin, were recorded for the first time in Alaska.
1H NMR and CD secondary structure analysis of cell adhesion promoting peptide F-9 from laminin.

A heparin binding, cell adhesion promoting domain, termed peptide F-9, from the B1 chain of human laminin, residues 641 to 660, i.e. RYVVLPRPVCFEKGMNYTVR, has been investigated by 1H NMR (500 MHz) spectroscopy and CD spectropolarimetry. While small linear peptides in water solution normally exist in a number of fluctuating conformational states, CD data analysis of peptide F9 indicates the existence of some preferred average structural populations consisting of about 30% beta-sheet, 22% beta-turn, and 6% alpha-helix. NMR structural analysis supports this observation and indicates specific sequences of preferred structural populations. Evidence for these is indicated by the presence of dNN nuclear Overhauser effect (NOE) populations and attenuated or absent d alpha N NOEs at short mixing times (0.1 s), 3J alpha N coupling constants of 5 and 10 Hz, and chemical shifts significantly removed from random coil positions. The NH2-terminal VVL sequence primarily exists in an extended chain conformation by virtue of large d alpha N NOEs and 9-10 Hz 3J alpha N coupling constants. Residues C10-N16 have turn-like or helix character with a run of dNN and d beta N NOEs and attenuated d alpha N NOEs. These midchain reversals include the lysine and asparagine residues proposed to be involved in heparin binding and N-glycosylation, respectively, to laminin peptide F-9.
Performance of 3-Dimensional Echocardiography in Measuring Left Ventricular Volumes and Ejection Fraction: A Systematic Review and Meta-Analysis

Objectives The primary aim of this systematic review is to objectively evaluate the test performance characteristics of three-dimensional echocardiography (3DE) in measuring left ventricular (LV) volumes and ejection fraction (EF). Background Despite its growing use in clinical laboratories, the accuracy of 3DE has not been studied on a large scale. It is unclear if this technology offers an advantage over traditional two-dimensional (2D) methods. Methods We searched for studies that compared LV volumes and EF measured by 3DE and cardiac magnetic resonance (CMR) imaging. A subset of those also compared standard 2D methods with CMR. We used meta-analyses to determine the overall bias and limits of agreement of LV end-diastolic volume (EDV), end-systolic volume (ESV), and EF measured by 3DE and 2D echocardiography (2DE). Results Twenty-three studies (1,638 echocardiograms) were included. The pooled biases ± 2 SDs for 3DE were −19.1 ± 34.2 ml, −10.1 ± 29.7 ml, and − 0.6 ± 11.8% for EDV, ESV, and EF, respectively. Nine studies also included data from 2DE, where the pooled biases were −48.2 ± 55.9 ml, −27.7 ± 45.7 ml, and 0.1 ± 13.9% for EDV, ESV, and EF, respectively. In this subset, the difference in bias between 3DE and 2D volumes was statistically significant (p = 0.01 for both EDV and ESV). The difference in variance was statistically significant (p Conclusions Three-dimensional echocardiography underestimates volumes and has wide limits of agreement, but compared with traditional 2D methods in these carefully performed studies, 3DE is more accurate for volumes and more precise in all 3 measurements.
Database audit and control strategies

Database management systems are the primary tools of automated record keeping, reporting, auditing, and control. Although they have significantly improved the efficiency and speed of record keeping, the ability to detect errors and maintain quality has not kept pace. There are three major strategies of error detection, auditing, and control to maintain integrity. The three strategies are introduced, and compared in terms of efficiency and effectiveness in eliminating errors. The optimum timing of audits under each strategy is computed. One strategy is shown to be completely dominated by the others. Hybrid strategies involving various combinations of the three pure strategies are introduced, and their performance computed. Hybrid strategies are shown to outperform the pure strategies under most realistic conditions. Finally, optimum audit strategies are devised, and their parameters computed.
Telehospice Tools for Caregivers: A Pilot Study

This pilot study introduces videophones into the homes of elderly caregivers of dying patients, evaluating their usefulness as a communication tool. A total of 12 senior caregivers from two hospice agencies were recruited into the study. Portable videophones were installed allowing caregivers to conduct video-calls with hospice staff. Findings indicate that the anxiety scores significantly decreased (p < 0.05) for participants over time. Differences in quality-of-life scores (including individual dimensions as well as overall score) were not statistically significant. Staff members at one of the participating hospice agencies were originally reluctant to recruit caregivers to the study. Videophones were perceived as easy to use by caregivers who overall saw benefit in the visual feedback during their communication with hospice staff.
The Uses of History in Marketing Education

Growing interest in marketing history is providing a major new focus for marketing studies. This article examines the benefits of adopting a historical perspective in teaching marketing. This perspective involves both the historical "facts" and the techniques employed by historians, which can be particularly useful in areas unsuited to the application of scientific method. Suggestions are made for incorporating history into the marketing curriculum.
Heterogeneous electron transfer kinetics for a variety of organic electrode reactions at the mercury-acetonitrile interface using either tetraethylammonium perchlorate or tetraheptylammonium perchlorate electrolyte

Abstract The electrode reactions of 26 compounds have been studied by cyclic voltammetry at mercury electrodes using acetonitrile as solvent and either 0.10 M tetraethylammonium perchlorate (TEAP) or 0.10 M tetra-n-heptylammonium perchlorate (THpAP) as supporting electrolyte. The standard potentials of the compounds ranged from −0.07 to −2.90 V vs. the Ag/AgNO 3 reference electrode. In several of the redox couples studied, the charge on the ionic partner was localized on a few atoms which is expected to cause the outer reorganization energy to be high, giving small electron transfer rate constants. However, is some instances it does not appear that the degree of charge localization is great enough to account fully for the small rate constants. It is argued that the inner reorganization energy should not be ignored in such cases. The rate constants observed for THpAP were always smaller than those for TEAP when the values were small enough to measure in at least one electrolyte. This general result was explained by a suppression of the probability of electron transfer by an adsorbed film containing mainly tetra-n-heptylammonium ions. The interpretation was supported by measurement of the activation parameters for nitroethane in the two electrolytes. The activation enthalpies were almost identical but the preexponential factor for THpAP was only 1/44 that for TEAP.
Identification of an essential residue of pig heart aconitase

Abstract Treatment of aconitase with phenacyl bromide prior to activation with Fe(II) and reductant results in complete, irreversible enzyme inactivation. Inactivation is due to the alkylation of a cysteine residue at the active site of the enzyme, the inactivation being inhibited by the competitive inhibitor, tricarballylate. Active enzyme is similarly inactivated, citrate affording greater protection than tricarballylate.
The optical analogy for vector fields

This paper develops the optical analogy for a general vector field. The optical analogy allows the examination of certain aspects of a vector field that are not otherwise readily accessible. In particular, in the cases of a stationary Eulerian flow v of an ideal fluid and a magnetostatic field B, the vectors v and B have surface loci in common with their curls. The intrinsic discontinuities around local maxima in absolute values of v and B take the form of vortex sheets and current sheets, respectively, the former playing a fundamental role in the development of hydrodyamic turbulence and the latter playing a major role in heating the X-ray coronas of stars and galaxies.
[Mo5VMo7VIO30(BPO4)2(O3P-Ph)6]5-: a phenyl-substituted molybdenum(V/VI) boro-phosphate polyoxometalate.

The title polyanion is the first hybrid borophosphate−phenylphosphonate polyoxometalate. It was structurally characterized as its imidazolium salt, (C3N2H5)5[Mo12O30(BPO4)2(O3P-Ph)6]·H2O (monoclini...
Assessment of the drug sensitivity of acute nonlymphocytic leukaemia using the in vitro clonogenic assay

Summary The ability of an in vitro clonogenic drug sensitivity assay to predict the outcome of therapy for acute nonlymphocytic leukaemia was evaluated using marrow cells obtained from previously untreated or first relapsed patients treated with either cytosine arabinoside/anthracycline antibiotic or high dose cytosine arabinoside remission induction therapy. While the per cent of leukaemic cells killed in vitro was correlated with the outcome of therapy, this drug sensitivity assay provided little or no clinically useful information. In 1980 we reported the results of our initial studies of an in vitro drug sensitivity assay designed to predict the response of patients with acute nonlymphocytic leukaemia (ANLL) to chemotherapy (Preisler, 198Oa). The studies described here extend our initial report and relate in vitro drug sensitivity to the biological characteristics of the leukaemic cells and to response to remission induction therapy with conventional dose cytosine arabinosidelanthracycline antibiotic therapy or ‘high dose’ cytosine arabinoside therapy.
A silicon micromachined conductometric gas sensor with a maskless Pt sensing film deposited by selected-area CVD

Abstract Inexpensive, conductometric gas micro-sensor platforms have been micromachined using conventional silicon processing. The front end of these sensors is a conducting film that undergoes resistance changes when exposed to certain chemical species. A variety of sensing film materials needs to be explored to obtain a significant sensor response above noise level for selected gases and vapors over wide ranges of temperature and pressure. However, only a few sensing film materials are compatible with the etchants used for silicon micromachining. To open up a wider range of materials for the sensing element, a new selected area CVD process is used to deposit thin conducting films on sensor platforms that have fully functioning conductance probes and integrated microheaters. This paper describes this selected-area CVD process for maskless deposition of thin platinum films with in-situ monitoring of film resistance during growth. Film growth is terminated at a desired value of resistance suitable for sensing of gases and vapors. The structure of the deposited films is characterized by scanning force microscopy. The response of Pt CVD films to H2, O2, CO, and propylene gases is reported.
Transfusion practice and outcomes in non-ST-segment elevation acute coronary syndromes.

Objectives To describe the association between transfusion and outcomes as a function of nadir hematocrit (HCT) in patients with non–ST-segment elevation acute coronary syndromes (NSTE ACS). Background The adverse outcomes associated with transfusion in NSTE ACS is uncertain and may vary by nadir HCT of the transfused. Methods Using data from 44 242 patients with NSTE ACS in 400 US hospitals in the CRUSADE initiative (January 2004-December 2005), we describe blood transfusion as a function of nadir HCT and associated outcomes across nadir HCT groups (≤24%, 24.1%-27%, 27.1%-30%, >30%). We further explore patient and process variation across hospital quartiles defined by transfusion use. Results Overall, 22.2% of patients with NSTE ACS are anemic and 10.4% receive a blood transfusion during their care. Likelihood of transfusion rose from 1% when nadir HCT was >30% to 70% when nadir HCT was ≤24%. The threshold for transfusion is a median nadir HCT of 25.7% (interquartile range 23.8%-27.5%). Although nadir HCT of transfused remains constant across quartiles of transfusion use, occurrence of bleeding increases. Inhospital mortality is higher in lower nadir HCT groups. In those with a nadir HCT of ≤24%, transfusion tended to have a beneficial impact on mortality (HCT ≤24% adjusted odds ratio [OR] 0.68 [0.45-1.02]). In the median range where transfusion occurs, transfusion had a neutral impact on mortality (HCT 24%-27% adjusted OR 1.01 [0.79-1.30]). Although rare, those transfused with nadir HCT of 27% to 30% (adjusted OR 1.18 [0.92-1.50]) or HCT of >30% (adjusted OR 3.47 [2.30-5.23]) had higher mortality. Conclusion Anemia and transfusion are common in the care of NSTE ACS. The observed association between transfusion and adverse outcomes is neutral in the nadir HCT range where transfusions are most often given and trends strongly to benefit when nadir HCT is ≤24%. Although reassuring, randomized trials are needed to confirm the safety of transfusion in NSTE ACS. In the meantime, avoiding the need for transfusion is the best approach.
Hyperalgesia induced in the rat by the amino-terminal octapeptide of nerve growth factor.

Abstract Nerve growth factor (NGF) in the mouse submandibular gland undergoes cleavage of its amino-terminal octapeptide when salivation is induced by epinephrine. The significance of this event is uncertain; cleaved NGF demonstrates bioactivity and no function has been attributed to the octapeptide produced (NGF-OP; Ser-Ser-Thr-His-Pro-Val-Phe-His). Enzyme inhibition studies indicating structural relatedness of NGF-OP and bradykinin (BK) prompted us to determine whether NGF-OP would elicit BK-like actions. We found that like BK, NGF-OP induced a decrease in mechanical nociceptive threshold (i.e., produced hyperalgesia) in the hairy skin of the rat. This effect was dose-dependent and sequence-specific; like BK it was attenuated by sympathectomy and indomethacin pretreatment. However, NGF-OP actions appeared to be distinct from those for BK in that tissue injury was required for NGF-OP to induce hyperalgesia. Furthermore, we found no evidence that NGF-OP bound to or activated BK receptors. Our data indicate that NGF-OP is a distinct mediator of hyperalgesia. We suggest that NGF-OP alters pain threshold in the injured target regions of NGF-responsive neurons.
The importance of dietary cholesterol in coronary heart disease.

Abstract Dietary cholesterol is important in the pathogenesis of atherosclerosis because of its strong influence in increasing the concentrations of plasma cholesterol and low-density lipoprotein (LDL). The cause and effect relationship of dietary cholesterol to atherosclerosis and plasma lipoproteins has been best demonstrated in the rhesus monkey: when fed dietary cholesterol, hypercholesterolemia, increased LDL, and later atherosclerosis and even myocardial infarction result. Significant regression of coronary atherosclerosis occurred when cholesterol was removed from the diet. Epidemiological observations throughout the world indicate a positive relationship between the amounts of dietary cholesterol and the mortality from coronary heart disease (CHD). In human beings, several dozen experiments show the strong influence of dietary cholesterol in increasing plasma cholesterol levels when the background diet is low in dietary cholesterol. The invariable result of dietary cholesterol feeding is an elevation of plasma cholesterol and LDL levels which occurs in normal subjects, in Tarahumara Indians, and in pregnant women, as well as in patients with a variety of hyperlipidemias. Even in outpatient studies conducted as a double-blind trial, dietary cholesterol had a hypercholesterolemic effect. However, in poorly controlled outpatient studies such effects have not always been demonstrated. Threshold and ceiling amounts for dietary cholesterol clearly exist for both animals and human beings. The threshold is that amount of dietary cholesterol which affects plasma cholesterol levels. As the quantity of cholesterol in the diet is gradually increased, the plasma cholesterol continues to rise until an apparent saturation point is reached. Thus, if one adds further large quantities of dietary cholesterol to an already cholesterol-rich diet, no further increase in plasma cholesterol concentrations will occur, because the ceiling has been exceeded. The “ceiling” explains why some experiments of dietary cholesterol feeding are negative.
Neutral Salt Effects on Stability of Whey Protein Isolate Foams

Addition of 0.1 M Na2SO4, NaCl, or NaSCN reduced maximum overruns of whey protein isolate (WPI) by 33%, 27%, and 38%. This was attributable to an ionic effect, i.e., the ions interacted with countercharges on the proteins thereby reducing electrostatic interactions. In contrast, at high concentrations (1M), Na2SO4 improved foam stability by 76% compared to WPI without salt. Chloride had an intermediate effect, whereas NaSCN did not improve foam stability. Increasing Na2SO4 concentration (2M) improved foam stability by 127% compared to control. The relative effectiveness of salts at improving foam stability and heat stability followed the Hofmeister series (SO42-<CI−<SCN−).
The multidimensional nature of party competition

Left—right is a convenient tool for summarizing the complexities of voter—party linkages in a manner that is comparable across contexts and that avoids the pathologies of preference aggregation in higher dimensions. Yet several reasons exist to believe that left—right is increasingly incapable of summarizing political behavior: the inability of left—right to capture policy concerns beyond economics and religion; the accumulation of new issue concerns over time; pressures for policy convergence stemming from the globalization of the world economy; and the decline of social cleavages that historically structured vote choice. This paper shows that parties are indeed talking about a growing number of issues, they are converging on the left—right scale, and the ideological cues they are sending to voters are growing increasingly ambiguous. Social democratic parties have in particular been affected by these trends.
Signals That Regulate Astroglial Gene Expression: Induction of GFAP mRNA Following Seizures or Injury Is Blocked by Protein Synthesis Inhibitors

Previous studies have revealed that a single electroconvulsive seizure (ECS) strongly induces glial fibrillary acidic protein (GFAP) expression in astrocytes in the hippocampal dentate gyrus. The signals that trigger this induction are not known, but circumstantial evidence suggests the hypothesis that GFAP expression may be induced as a result of the induction of growth factor expression by dentate granule cells that also occurs as a result of the ECS and other types of seizures. The present study tests one prediction of this hypothesis by evaluating whether increases in GFAP mRNA levels after ECS are blocked by inhibiting protein synthesis at various times after the ECS. We report that the upregulation of GFAP expression following ECS is blocked by protein synthesis inhibitors given 5 min before or up to 12 h after a single ECS. This temporal gradient suggests an intermediate step involving the increased expression of a protein growth factor.
Opioid peptides mediate the suppressive effect of stress on natural killer cell cytotoxicity

The cytotoxic activity of natural killer cells was investigated in rats subjected to one of two inescapable footshock stress paradigms, both of which induce analgesia, but only one via activation of opioid mechanisms. Splenic natural killer cell activity was suppressed by the opioid, but not the nonopioid, form of stress. This suppression was blocked by the opioid antagonist naltrexone. Similar suppression of natural killer activity was induced by high doses of morphine. These results suggest that endogenous opioid peptides mediate the suppressive effect of certain forms of stress on natural killer cell cytotoxicity.
Evaluation of an open source tool for indexing and searching enterprise radiology and pathology reports

Data mining of existing radiology and pathology reports within an enterprise health system can be used for clinical decision support, research, education, as well as operational analyses. In our health system, the database of radiology and pathology reports exceeds 13 million entries combined. We are building a web-based tool to allow search and data analysis of these combined databases using freely available and open source tools. This presentation will compare performance of an open source full-text indexing tool to MySQL's full-text indexing and searching and describe implementation procedures to incorporate these capabilities into a radiology-pathology search engine.
University of Colorado 52 inch cyclotron dee design

A dee with a useful aperature 49.5 in. in diameter by 1.29 in. high has been built. The external height is 2.00 in. The 0.35 inch thick top and bottom panels consist of 0.062 in. copper conductor which is cooled by water in 0.375 in. copper tubing, flattened to 0.25 in. The inside surface of the panel is 0.040 inch stainless steel—copper laminate. The panel assembly was brazed in a vacuum retort into a single piece. Atmospheric pressure was utilized to jig the parts during brazing. The entire exterior surface of the dee including the two flat panels) is water cooled copper sheet, which has been welded and brazed into a single surface. The interior structural frame is stainless steel.
Romantic Pretexts: Victorian Literary Appropriations in Anglo-Sino Discourse

Over the course of the long nineteenth century, Britain's relationship with China deteriorated from the high aspirations of George Lord Macartney's proposed diplomatic and economic partnership duri...
Revascularization of an Abdominal Aortic Aneurysm After Surgical Exclusion: Case Report and Literature Review

A high-risk patient underwent exclusion of an abdominal aortic aneurysm with aortofemoral bypass. During the procedure a horseshoe kidney was found to be overlying the aorta. Postoperatively retrograde perfusion of the aneurysm via a recanalized right iliac artery occurred and led to doubling of the aneu rysm's size, necessitating reoperation. The operative approach and pertinent literature are reviewed.
Performance of Working Class African-American Children on Three Tests of Articulation

The speech and language behaviors of African-American children, particularly those of lower socioeconomic status, have evoked considerable interest over the past two decades among scholars and prac...
Adult immigrant Latinas' Attitudes towards ESL Classes

Although the majority of limited English proficient adults in the United States are Hispanic immigrants with 12 years or less of school, few studies have looked at their special needs. This study looks particularly at immigrant Latinas. The most common reason for not attending ESL classes was the lack of childcare. The study also points up the need for information dissemination, including locations, times, and levels of classes. Respondents showed a strong preference for various features of a traditional classroom, particularly grammar instruction, error correction, tests, and 'mak[ing] sure that I understand everything'. This explains why in many districts teachers using natural or communicative approaches do not retain students as well as traditionalists, and why many students fail to achieve, despite the ample research showing the superiority of natural and communicative methods. Hence, teachers and programs need to clearly explain why they do what they do, and they may need to carefully frame the natural language lesson so that students feel they are learning something new and tangible in each class.