cssi/SciSciGPT-SciSciNet huggingface dataset:
Single and combination antibiotic therapy of Staphylococcus aureus experimental endocarditis: emergence of gentamicin-resistant mutants

The efficacy of nafcillin and gentamicin used alone and in combination at doses giving serum concentrations comparable to those achieved in patients was studied in rabbits with experimental Staphylococcus aureus endocarditis. The organism used was a penicillinase-producing, methicillin-susceptible, clinical isolate. The addition of gentamicin to nafcillin significantly increased the rate of killing of organisms in valvular vegetations, compared to the effect of nafcillin alone. Gentamicin alone delayed mortality but was not effective in reducing the bacterial populations of the vegetations. Bacteremia persisted in the animals treated with gentamicin alone, in contrast to the groups treated with nafcillin or the combination. Selection of a subpopulation of aminoglycoside-resistant small-colony variants occurred in animals treated with gentamicin alone. This variant was subsequently employed in the rabbit model and produced endocarditis, metastatic infection, and bacteremia comparable to those caused by the parent strain. Animals with infection produced by the variant died later than animals infected by the parent strain. Nafcillin was equally effective in reducing the population of both parent and variant strains in vitro and in therapy of the infected animals. Population studies showed the variant to be a mutant emerging at a rate of 1.9 x 10(-7). It was shown to differ from the parent strain in coagulase and hemolysin production, colonial morphology, and aminoglycoside susceptibility, but was similar by light and electron microscopy and in phage type, pigmentation of colonies, deoxyribonuclease production, mannitol fermentation, and growth rate.
Facilitated transport separation of benzene and cyclohexane with poly(vinyl alcohol)-AgNO3 membranes

Abstract Facilitated transport membranes of poly(vinyl alcohol) containing Ag(I) ions as the carrier were prepared and characterized using ultraviolet-visible spectroscopy (UV-Vis), elemental analysis (ICP-AE), scanning electron microscopy (SEM), and SEM(EDXR). Transport experiments were performed using benzene/cyclohexane feed mixtures having volume ratios of 8 2 and 2 8 (v/v). Permeation rates for benzene ranged 0.5 – 5.5 kg μm m−2 h−1 and benzene/cyclohexane selectivities ranged 51–84. Effects on membrane performance of Ag(I) content, counter ion used, hydration, and degree of cross-linking were investigated.
In Union There Is Strength: The Role of State Global Education Consortia in Expanding Community College Involvement in Global Education.

This chapter profiles state and regional global education consortia, the successes they have enjoyed, and the challenges they face. It concludes with recommendations for strengthening these associations and ensuring their continued existence and effectiveness.
Predictors of Hospitalization for Injection Drug Users Seeking Care for Soft Tissue Infections

BACKGROUND Soft tissue infections (STIs) from injection drug use are a common cause of Emergency Department visits, hospitalizations, and operating room procedures, yet little is known about factors that may predict the need for these costly medical services.
Comparison of Child and Adult Anthropometry: Considerations for Input Device Design

A systematic evaluation of child and adult anthropometry was carried out in order to determine anthropometric differences that may impact the design of computer input devices. Hand strength and the anthropometric measurements of shoulder breadth, hand length, hand breadth and finger width were compared among adults and 5, 10 and 14-year-old children. On average, children were 60% the size of adults at age 5 and 86% the size by age 14. The proportional size difference was relatively constant across the anthropometric measurements analyzed. At age 5, there was virtually no overlap in the size distribution between adults and children; by age 10, about 20% of the adult and child population were the same size, and by age 14, about 60% of the adult and child population were similar in size. When comparing hand strength, on average adults were five times stronger than 5-year-old children. The 5-fold strength difference and lack of overlap in the size distributions between young children and adults may have some ...
Enzyme purification using antibody crosslinked to protein A agarose: application to Escherichia coli NADP-isocitrate dehydrogenase.

Abstract A rapid and specific procedure has been developed for the isolation of NADP-specific isocitrate dehydrogenase from Escherichia coli. The column chromatographic procedure utilizes rabbit immunoglobin G specific for the enzyme crosslinked with dimethylsuberimidate to Protein A agarose. This stabilized immunoabsorbant can be regenerated, and utilized repeatedly for obtaining highly purified enzyme.
NEUTRINO ABSORPTION BY DEUTERIUM

Abstract The cross section for the reaction 2H(ν,e−)2p has been calculated as a function of neutrino energy using the effective range method to approximate the required nuclear matrix element. The cross section was averaged over the shape of the neutrino spectra from the decay of 15O and 8B. The results are σ av ( 15 O )=1.05× 10 −47 cm 2 and σ av ( 8 B )=1.20×10 −42 cm 2 . The uncertainty of both values is estimated to be ±10%.
Adsorption Modeling of Fatty and Oleic Estolide Esters via Boundary Lubrication Coefficient of Friction Measurements

The frictional behaviors of a variety of fatty esters (methyl palmitate (MP), methyl laurate (ML), and 2-ethylhexyl oleate (EHO)) and oleic estolide esters (methyl oleic estolide ester (ME) and 2-ethylhexyl oleic estolide ester (EHE)) as additives in hexadecane have been examined in a boundary lubrication test regime using steel contacts. Critical additive concentrations were defined and used to perform novel and simple Langmuir analyses that provide an order of adsorption energies: EHE ≥ ME > EHO > MP > ML. Application of a general adsorption model indicates slight cooperative adsorption of EHE, ME, and EHO. MP and ML data require larger attractive interaction terms (α ≤ −2.3) to be adequately fit. Irrespective of ester functionality increasingly negative adsorption energies appear to correlate with molecular weight. This suggests that multiple site coverage and multiple adsorptive interactions are likely for each of the esters studied.Copyright © 2005 by ASME
Superspreading mechanisms: An overview

An aqueous solution of trisiloxane-ethoxylate surfactants (superspreaders) has fascinating surface properties that promote rapid spreading over hydrophobic substrates and efficiently reduce the surface tension at the air/solution interface to 21–22 mN/m. Superspreaders have a variety of commercial and industrial applications, and can be used as adjuvants, surface modifiers for fabrics, cleaners and much more. Since their discovery in the 1960s, and despite their significant technological applications, the phenomenon that drives superspreading is still not well understood and is under continuous discussion. The goal of the presented review is to discuss and analyze the data presented in the literature and then to elucidate the concepts and mechanisms to explain what drives the fast rate of spreading. Two concepts are presented (and then excluded) for elucidating the understanding of the fast spreading rate over hydrophobic surfaces: the first concept concludes that the spreading is driven by the contact angle dynamics due to the reduction in the surface tension and/or interfacial tension of the solution/substrate leading to a decreased contact angle during spreading and the value of the spreading coefficient S ≥ 0, while the second concept attempts to show that the spreading is driven by the Marangoni flow over a stretching surface of a spreading drop or at the precursor film. However, neither the spreading coefficient, S ≥ 0, nor the Marangoni flow satisfactorily explains why the rate of spreading vs. the degree of surface wettability has a maximum. This review will help readers gain insight on superspreading and stimulate researchers to explore the superspreading phenomenon for novel applications.
Let‐7 modulates acquired resistance of ovarian cancer to Taxanes via IMP‐1‐mediated stabilization of multidrug resistance 1

Ovarian cancer patients frequently develop resistance to chemotherapy regiments using Taxol and carboplatin. One of the resistance factors that protects cancer cells from Taxol-based therapy is multidrug resistance 1 (MDR1). micro(mi)RNAs are small noncoding RNAs that negatively regulate protein expression. Members of the let-7 family of miRNAs are downregulated in many human cancers, and low let-7 expression has been correlated with resistance to microtubule targeting drugs (Taxanes), although little is known that would explain this activity. We now provide evidence that, although let-7 is not a universal sensitizer of cancer cells to Taxanes, it affects acquired resistance of cells to this class of drugs by targeting IMP-1, resulting in destabilization of the mRNA of MDR1. Introducing let-7g into ADR-RES cells expressing both IMP-1 and MDR1 reduced expression of both proteins rendering the cells more sensitive to treatment with either Taxol or vinblastine without affecting the sensitivity of the cells to carboplatin, a non-MDR1 substrate. This effect could be reversed by reintroducing IMP-1 into let-7g high/MDR1 low cells causing MDR1 to again become stabilized. Consistently, many relapsed ovarian cancer patients tested before and after chemotherapy were found to downregulate let-7 and to co-upregulate IMP-1 and MDR1, and the increase in the expression levels of both proteins after chemotherapy negatively correlated with disease-free time before recurrence. Our data point at IMP-1 and MDR1 as indicators for response to therapy, and at IMP-1 as a novel therapeutic target for overcoming multidrug resistance of ovarian cancer.
Rapid and reversible activation of acetyl CoA hydrolase in intact pineal cells by disulfide exchange

Abstract Using intact pinealocytes in suspended cell culture it has been determined that acetyl CoA hydrolase activity can be rapidly increased by treatment with cystamine. Similar results are seen with diacetylcystamine, but not with GSSG, penicillamine disulfide, nor with oxidized DTT. The activation of acetyl CoA hydrolase by cystamine is reversible: after cystamine treatment is terminated, enzyme activity decreases slowly in cell culture. It is also possible to reverse the activation by treating homogenates of cystamine-treated cells with dithiothreitol. These observations are consistent with previous findings indicating that pineal acetyl CoA hydrolase activity can be regulated via protein thiol: disulfide exchange. The observations presented in this report also indicate that conditions within the cell allow this type of reaction to take place, and raise the possibility that disulfide exchange mechanisms may be physiologically involved in the intracellular regulation of the activity of this and perhaps other enzymes.
Transient compositional effects from feeders in a starved flow modular co‐rotating twin‐screw extruder

A process dynamics model of transient output composition variations in a moduar self-wiping twin-screw extruder caused by input disturbances from feeders is developed. The changes of output mass flow rate and weight fraction of additives in the output stream were predicted for various time dependent input modes into a second feeder and other ports part way along the length of the machine.
The Relationship between task complexity and information search: The role of self‐efficacy

Prior research suggests the complexity of a product choice task is inversely related to the extent of consumers' external information search. The resource-matching perspective holds that cognitive effort (e.g., external information search) is greatest when available cognitive resources (e.g., as determined by self-efficacy) match the cognitive demands of a task (e.g., perceived task complexity). Within a brand-choice context, the relationship between self-efficacy and extent of information search appears nonmonotonic. In support of the resource-matching perspective, consumers conduct the most extensive information search when their self-efficacy matches perceived task difficulty. © 2007 Wiley Periodicals, Inc.
Retinoic acid regulates insulin-like growth factor-binding protein expression in human osteoblast cells.

Retinoic acid (RA) regulates the growth and differentiation of numerous cells types and plays a key role in skeletal development. Previous studies have demonstrated that insulin-like growth factors (IGFs) are important local regulators of bone cell proliferation and differentiation and that IGF-binding proteins (IGFBPs) modulate their activities. In an attempt to test the hypothesis that RA mediates its effects on bone cells in part by regulating IGFBP expression, we first examined the effect of RA on IGFBP expression in human osteoblast model systems and then compared these responses to the effects of RA on IGFBP expression in human skin fibroblasts. The most dramatic effect of RA on IGFBPs++ in all cell types tested was to increase IGFBP-6 messenger RNA (mRNA) abundance more than 1000% of the control value. Significant effects on IGFBP-5 mRNA abundance were also found, with maximal reductions to 35% of control within 24 h of treatment. In addition, RNA maximally increased IGFBP-3 and -4 mRNA to 580% and...
SURFACE NONLINEAR OPTICS : A HISTORICAL OVERVIEW

The availability of widely tunable dye lasers and optical parametric oscillators permit the detection of surface specific electronic and vibrational states. Polarization dependent studies yield information about the orientation of molecular monolayers and surface specific bonds. The use of picosecond and femtosecond pulse–probe techniques permits time-resolved studies of surface phase transformations, desorption, and melting. A few examples from the rapidly growing literature are selected to illustrate this historical evolution.
Siding with the underdog: is your customer voting effort a sweet deal for your competitors?

In this research, we explore the negative consequences of engaging customer participation through voting mechanisms. Specifically, we draw attention to the double risk of customer voting, first by identifying the adverse effects of losing, and then by revealing the potential of turning an already engaged set of customers over to underdog competitors. We first establish that the losing effect is distinct from that of a voting (empowerment) effect (Pilot Study). We then replicate the losing effect and show that losing (as opposed to winning) voters tend to experience stronger levels of disempowerment and identify more with the underdog (Study 1). Finally, we demonstrate that losing voters are more likely to choose a competitor brand over the incumbent brand, particularly when the competitor is perceived to be an underdog (Study 2). Our findings caution brand managers to reconsider their customer engagement strategy when it involves customer voting.
Reusable ontologies, knowledge-acquisition tools, and performance systems: PROTE´GE´-II solutions to Sisyphus-2

Abstract This paper describes how we applied the PROTEGE-II architecture to build a knowledge-based system that configures elevators. The elevator-configuration task was solved originally with a system that employed the propose-and-revise problem-solving method (VT). A variant of this task, here named the Sisyphus-2 problem, is used by the knowledge-acquisition community for comparative studies. PROTEGE-II is a knowledge-engineering environment that focuses on the use of reusable ontologies and problem-solving methods to generate task-specific knowledge-acquisition tools and executable problem solvers. The main goal of this paper is to describe in detail how we used PROTEGE-II to model the elevator-configuration task. This description provides a starting point for comparison with other frameworks that use abstract problem-solving methods. Beginning with the textual description of the elevator-configuration task, we analysed the domain knowledge with respect to PROTEGE-II’s main goal: to build domain-specific knowledge-acquisition tools. We used PROTEGE-II’s suite of tools to construct a knowledge-based system, called ELVIS, that includes a reusable domain ontology, a knowledge-acquisition tool, and a propose-and-revise problem-solving method that is optimized to solve the elevator-configuration task. We entered domain-specific knowledge about elevator configuration into the knowledge base with the help of a task-specific knowledge-acquisition tool that PROTEGE-II generated from the ontologies. After we constructed mapping relations to connect the knowledge base with the method’s code, the final executable problem solver solved the test case provided with the Sisyphus-2 material. We have found that the development of ELVIS has afforded a valuable test case for evaluating PROTEGE-II’s suite of system-building tools. Only projects based on reasonably large problems, such as the Sisyphus-2 task, will allow us to improve the design of PROTEGE-II and its ability to produce reusable components.
Addition of β-mercaptoethanol produced stable crystals of Theiler's virus

Abstract Theiler's murine encephalomyelitis virus (TMEV) is a small spherical RNA virus with a diameter of 300 A. In order to determine its three-dimensional structure by X-ray crystallography, crystallization conditions were searched to grow large single crystals of purified virus. During the study, several crystalline forms were obtained under various conditions, but they all appeared to be very fragile and showed rapid fatal deterioration upon exposure to X-ray radiation. By addition of 0.1% v/v β-mercaptoethanol to the virus and precipitant solutions, a stable tetragonal crystalline form was produced. These large single crystals diffracted X-rays to at least 3.0 A resolution and the X-ray diffraction data were used to determine the atomic structure of Theiler's virus.
A new technique for characterizing low-defect simox

Abstract Defect density in thin top silicon layer of SIMOX materials was investigated. TEM characterization of low-defect ( 6 cm −2 ) SIMOX was both cost and time prohibitive to inspect large areas. A new technique using a diluted Secco etch followed by a hydrofluoric acid decoration was developed to identify unambiguously such defects. The technique utilizes the same etchant and equipment used for defect characterization of single-crystalline silicon wafers and is found useful in SOI device development.
Comprehensive study of the electronic and optical behavior of highly degenerate p-type Mg-doped GaN and AlGaN

The bulk and 2-dimensional (2D) electrical transport properties of heavily Mg-doped p-type GaN films grown on AlN buffer layers by Metal Modulated Epitaxy are explored. Distinctions are made between three primary p-type conduction mechanisms: traditional valence band conduction, impurity band conduction, and 2D conduction within a 2D hole gas at a hetero-interface. The bulk and 2D contributions to the overall carrier transport are identified and the relative contributions are found to vary strongly with growth conditions. Films grown with III/V ratio less than 1.5 exhibit high hole concentrations exceeding 2 × 1019 cm−3 with effective acceptor activation energies of 51 meV. Films with III/V ratios greater than 1.5 exhibit lower overall hole concentrations and significant contributions from 2D transport at the hetero-interface. Films grown with III/V ratio of 1.2 and Mg concentrations exceeding 2 × 1020 cm−3 show no detectable inversion domains or Mg precipitation. Highly Mg-doped p-GaN and p-AlGaN with Al...
Cattle blood group J glycolipid. I. Isolation and identification of the trihexoside ceramide component of J hapten.

Abstract A lipid preparation which inhibited the hemolysis of bovine Jcs red cells was isolated from bovine Jcs serum by extraction, column chromatography and preparative thin layer chromatography. This preparation contained long chain base, fatty acid, glucose, galactose, phosphorus and glycerol. The J activity was lost when this preparation was subjected to alkaline treatment. Prolonged alkaline methanolysis of the J active lipid afforded a glycolipid identical in base and sugar composition and ratios to the parent J active lipid. It is assumed, therefore, that the isolated glycolipid is part of the larger structure which inhibits J activity. From a study of the quantitative composition of the glycolipid and by a thin-layer chromatography comparison of its migration with that of glycolipid standards, it was concluded that the glycolipid was trihexoside ceramide. Study of the carbohydrate sequence in the glycolipid by mild acid methanolysis has established that glucose is linked to the long chain base and that galactose is the terminal sugar. The study of long chain base composition of this glycolipid has established presence of a number of bases. The principal bases were sphinganine, heptadecasphinganine and sphingenine. Palmitate, stearate and isostearate were the principal fatty acids found in this glycolipid.
IMPROVED GEODETIC RESULTS FROM CAMERA OBSERVATIONS OF SATELLITES

Analysis of Baker Nunn camera observations of satellites 1959α1 over 1032 days; 1959η over 792 days; 1960t2 over 480 days; 1961δ1 over 150 clays; and 1961αδ1 over 54 days yielded results greatly improved over those previously reported. This improvement is primarily due to the use of much more data and secondarily to various modifications in the method of analysis. As indicated by the discrepancies between results from appreciably different orbits, the datum shifts obtained have standard deviations of ±4 to ±23 meters. The tesseral harmonic of the gravity field most firmly determined appears to be J11, followed by J22, J31, J42, J13, and J32. The principal sources of error suggested are the influence of preassigned variances on separation of gravitational coefficients having the same periodic effects on an orbit (e.g., J22 and J42) and the holding fixed with respect to each other stations on the same geodetic datum, but they do not seem adequate to explain all systematic discrepancies in the results. A comparison of gravitational and geometric geoid heights at station positions gave a mean equatorial radius of 6,378,196±11 meters.
Fine Structure of the Meissner Corpuscle of Human Palmar Skin

Meissner corpuscles of human palmar skin were investigated with the electron microscope. The upper margin of the corpuscle was in direct contact with the epidermal basal cells without interposition of the basal lamina. Although no specialized junctions were formed, axon terminals and accompanying laminar cells were interdigitated with the basal cells. Axons, both those in contact with the epidermis and those terminated within the corpuscle, contained a number of mitochondria, microvesicles similar to synaptic vesicles, and myelinated dense bodies. Some axon terminals contained dense granules identical to those of the Merkel cell or chromaffin cells. Axon cylinders were enveloped with single or multiple layers of laminar cells and their processes which produced desmosome-like junctions between them. Laminar cell nuclei tended to localize at the periphery of the corpuscle and their cytoplasm extended unipolarly. Slender cytoplasmic processes often produced desmosome-like junctions between themselves, contained numerous pinocytotic vesicles, and were surrounded with a basal lamina in many areas. The laminar cell was considered to be a modified Schwann cell. Spaces between laminar cells and their processes were filled with an interlaminar substance which was composed of an admixture of basal lamina materials, microfilaments, and collagen fibrils.
Glia Modulate NMDA‐Mediated Signaling in Primary Cultures of Cerebellar Granule Cells

Abstract: Excessive activation of N-methyl-d-aspartate (NMDA) receptor channels (NRs) is a major cause of neuronal death associated with stroke and ischemia. Cerebellar granule neurons in vivo, but not in culture, are relatively resistant to toxicity, possibly owing to protective effects of glia. To evaluate whether NR-mediated signaling is modulated when developing neurons are cocultured with glia, the neurotoxic responses of rat cerebellar granule cells to applied NMDA or glutamate were compared in astrocyte-rich and astrocyte-poor cultures. In astrocyte-poor cultures, significant neurotoxicity was observed in response to NMDA or glutamate and was inhibited by an NR antagonist. Astrocyte-rich neuronal cultures demonstrated three significant differences, compared with astrocyte-poor cultures: (a) Neuronal viability was increased; (b) glutamate-mediated neurotoxicity was decreased, consistent with the presence of a sodium-coupled glutamate transport system in astrocytes; and (c) NMDA- but not kainate-mediated neurotoxicity was decreased, in a manner that depended on the relative abundance of glia in the culture. Because glia do not express NRs or an NMDA transport system, the mechanism of protection is distinct from that observed in response to glutamate. No differences in NR subunit composition (evaluated using RT-PCR assays for NR1 and NR2 subunit mRNAs), NR sensitivity (evaluated by measuring NR-mediated changes in intracellular Ca2+ levels), or glycine availability as a coagonist (evaluated in the presence and absence of exogenous glycine) were observed between astrocyte-rich and astrocyte-poor cultures, suggesting that glia do not directly modulate NR composition or function. Nordihydroguaiaretic acid, a lipoxygenase inhibitor, blocked NMDA-mediated toxicity in astrocyte-poor cultures, raising the possibility that glia effectively reduce the accumulation of highly diffusible and toxic arachidonic acid metabolites in neurons. Alternatively, glia may alter neuronal development/phenotype in a manner that selectively reduces susceptibility to NR-mediated toxicity.
Molecular Antagonism and Plasticity of Regulatory and Inflammatory T Cell Programs

Regulatory T (Treg) and T helper 17 (Th17) cells were recently proposed to be reciprocally regulated during differentiation. To understand the underlying mechanisms, we utilized a Th17 reporter mouse with a red fluorescent protein (RFP) sequence inserted into the interleukin-17F (IL-17F) gene. Using IL-17F-RFP together with a Foxp3 reporter, we found that the development of Th17 and Foxp3(+) Treg cells was associated in immune responses. Although TGF-beta receptor I signaling was required for both Foxp3 and IL-17 induction, SMAD4 was only involved in Foxp3 upregulation. Foxp3 inhibited Th17 differentiation by antagonizing the function of the transcription factors RORgammat and ROR*. In contrast, IL-6 overcame this suppressive effect of Foxp3 and, together with IL-1, induced genetic reprogramming in Foxp3(+) Treg cells. STAT3 regulated Foxp3 downregulation, whereas STAT3, RORgamma, and ROR* were required for IL-17 expression in Treg cells. Our data demonstrate molecular antagonism and plasticity of Treg and Th17 cell programs.
Studies of the dynamic properties of Langmuir probes III: Discussion of the results☆

Abstract The results obtained during the study of the dynamic properties of a Langmuir probe are discussed. Since a mathematical description of the transient behavior of a space-charge sheath is mathematically very complicated if not impossible, a qualitative theory explaining all phenomena observed is presented. This theory is based on the relatively slow motion of positive ions with respect to that of the electrons as well as on the transient distortion of the plasma region adjacent to the probe-plasma sheath. It is found that the plasma distortion may have a large influence on the probe current collection when the final probe potential is close to plasma potential. In the same region there is a possibility that transient space-charge barriers, which prevent charged particles temporarily from being collected by the probe, are produced by a sudden change in probe potential.
A holistic approach for optimal design of air quality monitoring network expansion in an urban area

This paper presents an objective methodology for determining the optimum number of ambient air quality stations in a monitoring network. The methodology integrates the multiple-criteria method with the spatial correlation technique. The pollutant concentration and population exposure data are used in this methodology in different ways. In the first stage, the Fuzzy Analytic Hierarchy Process (FAHP) with triangular fuzzy numbers (TFNs) is used to identify the most desirable monitoring locations. The network configuration is then determined on the basis of the concept of sphere of influences (SOIs). The SOIs are dictated by a predetermined cutoff value (rc) in the spatial correlation coefficients (r) between the pollutant concentrations at the monitoring stations identified from first step and the corresponding concentrations at neighboring locations in the region. Finally, the optimal station locations are ranked by using combined utility scores gained from the first and second steps. The expansion of air quality monitoring network of Riyadh city in Saudi Arabia is used as a case study to demonstrate the proposed methodology.
The Neural Basis of Innate Behavior: II. Relative Effects of Partial Decortication in Adulthood and Infancy Upon the Maternal Behavior of the Prim I Parous Rat

* Received in the Editorial Office on December 29, 1937. 1 This study was supported by a grant from the Committee on Research in Problems of Sex of the National Research Council. The author wishes to express his gratitude to Dr. K. S. Lashley for his advice and encouragement given unsparingly throughout the conduction of actual experimentation and organization of results.
K+-induced alterations of energetics and exchange diffusion in the carrier-mediated transport of the folic acid analog, methotrexate, in ehrlich ascites tumor cells

Abstract The bidirectional fluxes and energetics of methotrexate transport in Ehrlich ascites tumor cells were profoundly altered in a high [K + ], low [Na + ] buffer (K + buffer). Incubation of cells for 30 min in K + buffer reduced influx by 27% and the efflux rate constant by 53%. This asymmetrical inhibition of bidirectional fluxes increased the net exchangeable intracellular methotrexate level per cell, but the actual intracellular methotrexate concentration at the steady state was similar to that in Na + buffer, since the high [K + ] caused an increase in intracellular water. Because cells exposed to K + buffer were depolarized, the apparent electrochemical potential difference for methotrexate was markedly reduced. However, the steady-state intracellular methotrexate level was still related to the extracellular concentration by an absorption isotherm, indicating asymmetry in the bidirectional fluxes similar to that observed in Na + buffer and thus predicting that transmembrane gradients would be produced at very low extracellular methotrexate concentrations. Glucose, which had little effect on bidirectional fluxes and reduced the steady-state level of methotrexate in Na + buffer, stimulated influx, inhibited efflux and rapidly increased the steady state in K + buffer similar to the effects of glucose in the presence of iodoacetate in Na + buffer. Finally, cells exposed to K + buffer exhibited trans -stimulation of [ 3 H]methotrexate influx when loaded with non-labeled methotrexate, a phenomenon not observed in Na + buffer. The results indicate that although methotrexate transport is not affected by transient changes in the cationic composition of the extracellular compartment, prolonged exposure of cells to a high [K + ], low [Na + ] environment markedly alters the physical properties of the cells and the transport parameters for methotrexate and reveals characteristics of the methotrexate carrier system that are not evident in other buffer systems.
Comorbid substance and mental disorders among rural Americans: results from the National Comorbidity Survey.

Abstract Background The purpose of this study was to examine whether rural inhabitants were more likely than urban inhabitants to meet the criteria for comorbid mental health and substance abuse or dependence disorders. Methods Data were from the National Comorbidity Survey, and included 5185 (532 = rural; 4653 = urban) persons age 14–54 years of age who were interviewed using the Composite International Diagnostic Interview (CIDI). Logistic regression that accounted for the complex survey data and weighting scheme was utilized. Results Participants residing in rural areas were more likely to meet the DSM-III-R criteria for past month alcohol abuse or dependence if they also met the diagnostic criteria for past month major depressive disorder (MDD) or lifetime antisocial personality disorder (ASPD), adjusting for age, race, gender, education and income. Similarly, rural participants were more likely to meet the criteria for comorbid drug abuse or dependence in the past month if they met the diagnosis for either past month MDD, generalized anxiety disorder or lifetime ASPD, controlling for demographic characteristics. Rural residents with any current mental disorder also were less likely to seek treatment than their urban counterparts. Limitations Data were collected in 1991 and do not capture changes in prevalence of comorbidities. Also, the small number of rural residents sampled resulted in small cell sizes for some comorbidities. Conclusions Rural residents were significantly more likely to meet the criteria for substance disorders given they also met the criteria for a mental disorder, and those with any current mental disorder were less likely to seek treatment. Since the overall prevalence of these disorders does not differ between rural and urban inhabitants, findings suggest that rural persons may lack access to adequate treatment for their mental health disorders and subsequently may be self-medicating with alcohol and/or drugs.
The Heliospheric Termination Shock

The heliospheric termination shock is a vast, spheroidal shock wave marking the transition from the supersonic solar wind to the slower flow in the heliosheath, in response to the pressure of the interstellar medium. It is one of the most-important boundaries in the outer heliosphere. It affects energetic particles strongly and for this reason is a significant factor in the effects of the Sun on Galactic cosmic rays. This paper summarizes the general properties and overall large-scale structure and motions of the termination shock. Observations over the past several years, both in situ and remote, have dramatically revised our understanding of the shock. The consensus now is that the shock is quite blunt, is with the front, blunt side canted at an angle to the flow direction of the local interstellar plasma relative to the Sun, and is dynamical and turbulent. Much of this new understanding has come from remote observations of energetic charged particles interacting with the shock, radio waves and radiation backscattered from interstellar neutral atoms. The observations and the implications are discussed.
Computed tomography and ultrasound demonstration of squamous cell carcinoma of the kidney

The computed tomography and ultrasound appearance of a case of squamous cell carcinoma of the kidney is reported and the relevant clinical and urographic findings in this rare entity are reviewed.
Modification of the SPUR rangeland model to simulate species composition and pasture productivity in humid temperate regions

Abstract Plant, water, and soil components of the Simulation of Production and Utilization of Rangelands model (SPUR 2.4) were incorporated into the Integrated Farm System Model (IFSM 1.2) to represent the growth and competition of multiple plant species in pastures and their effects on pasture productivity and botanical composition in temperate climates. Developed for semi-arid rangelands, SPUR required major adjustment to represent temperate pastures adequately. In particular, the effects of soil moisture on root and shoot mortality and photosynthetic rates were adjusted to represent greater susceptibility of temperate plants to drought. Sensitivity analysis showed that predicted total shoot dry matter appeared most sensitive to photosynthesis and growth parameters in the spring, soil moisture parameters in the summer, and senescence parameters in autumn. Across all seasons, shoot dry matter appeared most sensitive to optimum photosynthetic temperatures, specific leaf area, start and end dates of senescence, maximum nitrogen concentration in live shoots, and a maximum shoot specific growth rate. The revised pasture model incorporated into IFSM was calibrated with 2002 field data from experimental pastures in central Pennsylvania, USA containing primarily orchardgrass (Dactylis glomerata) and white clover (Trifolium repens). Predictive accuracy of the model was then further evaluated by comparing 2003 data from the same pastures to simulated production. The integrated submodel predicted soil water content and dry matter production relatively well. It did not achieve a desired degree of accuracy in predicting the dynamics of botanical composition; however, adjustment of SPUR subroutines to allow variable maximum root:shoot ratios and competition for light and water may improve predictions. Further development and use of this integrated model can help researchers improve their understanding of temperate pasture systems, identify gaps in knowledge, and prioritize future research needs. Ultimately, the integrated model could provide more accurate assessment of the influence of management strategies on pasture productivity, animal production, and economics at the whole-farm scale.
Elastodynamic stress intensity factors of a crack near an interface

Abstract The elastodynamic problem of the diffraction of stress waves by a crack near an interface is considered. Using integral transform techniques the case of a crack perpendicular to the interface is reduced to a system of singular integral equation. The stress intensity factors at the crack tips are calculated by numerical techniques over a range of frequency for different material properties and crack distances from the interface.
Brain Dynamics and Hypnosis: Attentional and Disattentional Processes

This article reviews recent research findings, expanding an evolving neuropsychophysiological model of hypnosis (Crawford, 1989; Crawford & Gruzelier, 1992), that support the view that highly hypnotizable persons (highs) possess stronger attentional filtering abilities than do low hypnotizable persons, and that these differences are reflected in underlying brain dynamics. Behavioral, cognitive, and neurophysiological evidence is reviewed that suggests that highs can both better focus and sustain their attention as well as better ignore irrelevant stimuli in the environment. It is proposed that hypnosis is a state of enhanced attention that activates an interplay between cortical and subcortical brain dynamics during hypnotic phenomena, such as both attentional and disattentional processes, among others, are important in the experiencing of hypnosis and hypnotic phenomena. Findings from studies of electrocortical activity, event-related potentials, and regional cerebral blood flow during waking and hypnosis are presented to suggest that these attentional differences are reflected in underlying neurophysiological differences in the far fronto-limbic attentional system.
Determination of the deuterium/hydrogen ratio in gas reaction products by laser-induced breakdown spectroscopy

Abstract This paper reports the first application of laser-induced breakdown spectroscopy technique (LIBS) to the determination of deuterium/hydrogen numeric ratio (β) in the headspace gases, essentially HD + H2, that are generated by the hydrolysis of NaBD4–NaBH4 mixtures (molar fraction of NaBD4, x = 50–100%) in acidic H2O media (0
The absolute abundance of the chromium isotopes in some secondary minerals

Abstract Isotopic assays have been made on the chromium in samples from fourteen different chrominiferous minerals from different geographic and meteoritic sources. The results of the assays indicate that it is not possible to unequivocally state that variations in isotopic composition have been observed.
Secondary Ion Mass Spectrometry of Poly(styrene-co-isoprene) Diblock Copolymers: Improved Surface Sensitivity Using the High-Mass Region

Thin film preparations of symmetric poly(styrene-co-isoprene) (PS−PI) diblock copolymers on silver were examined by TOF-SIMS. This diblock system is known to segregate, forming a PI block layer at ...
Subchronic Oral and Intravenous (iv) Safety Evaluation and Pharmacokinetics in Rats and Dogs of Ipazilide Fumarate (Win 54, 177-4), an Antiarrhythmic Agent

Abstract Ipazilide fumarate (Win 54,177-4) is a chemically novel antiarrhythmic agent that prolongs ventricular refractoriness and possesses antiectopic activity. Subchronic (29 days) nonclinical safety evaluation of ipazilide was conducted following oral and iv administration in Sprague-Dawley rats (20–320 mg/kg oral and 1.25 – 10 mg/kg iv) and 14 and 28 days in beagle dogs (3–30 mg/kg oral and 2.5–20 mg/kg iv). The pharmacokinetic parameters of ipazilide indicate that ipazilide is absorbed ( t max ≤ 1 hr) in fasted rats and dogs following single and repeated oral administrations. The apparent elimination half-life in the two species is approximately 1 hr (except in rats at a dosage of 320 mg/kg), suggesting rapid clearance. Increases in liver weights (rats 320 mg/kg) accompanied by the observation of centrilobular hypertrophy of hepatocytes were considered an expression of an adaptive metabolic response of the liver to ipazilide and may be associated with the induction of microsomal enzymes. Duodenal villous atrophy and epithelial hyperplasia (rats, 80 and 320 mg/kg) were interpreted to represent an irritant response to the drug. Local irritation was also observed at the injection site in rats and dogs. Dogs tolerated the oral and the iv administration of ipazilide at dosages of up to 30 and 20 mg/kg, respectively. Despite emesis (oral dogs), which was reduced in frequency following repeated treatment over several weeks, plasma levels in treated dogs (i.e., C max 4–5 μ g/ml) were approximately twice that required to convert spontaneous arrhythmias in the conscious dog model 24 hr after myocardial infarction. Moreover, plasma levels ( C max 6–7 μ g/ml) of iv-treated dogs were approximately three times higher than the efficacious levels in the dog model and did not cause adverse effects except emesis. Electrocardiographic changes (i.e., increased P wave and QRS durations, and T wave alterations) in dogs were transient and represented an extension of the pharmacological effects of ipazilide. In summary, since ipazilide, at multiple therapeutic dosages, was well tolerated in rats and dogs, it may be considered an appropriate drug for clinical evaluation of safety and efficacy in humans as a potential antiarrhythmic agent. The safety profile of ipazilide in clinical trials is currently ongoing.
Syntheses with stable isotopes: Oleic-1-13C acid and triolein-1′,1″, 1″′-13C3

A synthesis of oleic-1-13C acid and its conversion to triolein-1′,1″,1″′-13C3 are described. 9-Octadecynenitrile-1-13C was prepared from 1-bromo-8-heptadecyne and sodium cyanide-13C. Hydrolysis afforded stearolic-1-13C acid, which was reduced to oleic-1-13C acid by the action of disiamylborane on methyl stearolate-1-13C. Hydrogenation of stearolic acid in the presence of Lindlar's catalyst was also investigated. Condensation of glycerol and oleic-1-13C acid to give triolein-1′,1″,1″′-13C3 was effected with dicyclohexylcarbodiimide and 4-dimethylaminopyridine. The overall yield of triolein-13C3 from sodium cyanide-13C was 40%.
Robust automated instrument for measuring the focal length of a lens

An instrument has been prototyped for the purpose of determining the effective focal length of a spherical lens. The instrument employs a two-dimensional position-sensitive detector, two diode laser modules, a microcontroller, and an LCD readout. The system is designed to be automated, be immune to modest misalignment of the test lens, require no mechanical adjustments or image processing, and be accurate for spherical lenses with positive or negative focal lengths in the range of 25 mm f |<1,000 mm, and lens diameters no less than 25 mm. The user only needs to insert the test lens. By incorporating a Fourier lens in front of the detector and averaging the signals from the two beams that enter the system parallel and symmetrical with respect to the optic axis, the effect of a modest longitudinal, lateral, or tilt misalignment may be negated.
The Dopamine Transporter Constitutively Internalizes and Recycles in a Protein Kinase C-regulated Manner in Stably Transfected PC12 Cell Lines

The dopamine transporter (DAT) removes dopamine from the extracellular milieu and is potently inhibited by number of psychoactive drugs, including cocaine, amphetamines, and methylphenidate (Ritalin). Multiple lines of evidence demonstrate that protein kinase C (PKC) down-regulates dopamine transport, primarily by redistributing DAT from the plasma membrane to endosomal compartments, although the mechanisms facilitating transporter sequestration are not defined. Here, we demonstrate that DAT constitutively internalizes and recycles in rat pheochromocytoma (PC12) cells. Temperature blockades demonstrated basal internalization and reliance on recycling to maintain DAT cell surface levels. In contrast, recycling blockade with bafilomycin A1 significantly decreased transferrin receptor (TfR) surface expression but had no effect on DAT surface levels, suggesting that DAT and TfR traffic via distinct endosomal mechanisms. Kinetic analyses reveal robust constitutive DAT cycling to and from the plasma membrane, independent of transporter expression levels. In contrast, phorbol ester-mediated PKC activation accelerated DAT endocytosis and attenuated transporter recycling in a manner sensitive to DAT expression levels. These data demonstrate constitutive DAT trafficking and that PKC-mediated DAT sequestration is achieved by a combination of accelerated internalization and reduced recycling. Additionally, the differential sensitivity to expression level exhibited by constitutive and regulated DAT trafficking suggests that these two processes are mediated by independent cellular mechanisms.
Facial shell temporary veneers: Reducing chances for misunderstanding

Abstract With increasing demand for esthetically pleasing porcelain veneers, dentists face the challenge of delivering final restorations that fulfill patients' expectations. Given that “beauty is in the eye of the beholder,” dentists need a method of determining the cosmetic outcomes that the patient hopes to achieve. This article presents procedures that allow patients to “preview” the veneers before the final restorations are fabricated. This provisional restorative method can clarify patient expectations and reduce the need for costly remakes.
Intraperitoneal Thrombolytic Therapy for Peritoneal Dialysis–Associated Peritonitis

OBJECTIVE:To review the literature pertaining to the use of adjunctive thrombolytic therapy for the treatment of peritoneal dialysis–associated peritonitis (PDAP).DATA SOURCES:A MEDLINE search was conducted (January 1966– December 1997) to find articles using the terms peritonitis, peritoneal dialysis, and each thrombolytic drug. References from these articles were then reviewed to identify further sources.DATA EXTRACTION:Representative case reports and clinical trials are summarized in this report. Information regarding thrombolytic dosing, administration techniques, and reported efficacy rates are included from both case reports and clinical trials.DISCUSSION:Thrombolytic agents administered intraperitoneally appear to facilitate antibiotic penetration into the biofilm formed by certain bacteria. Numerous case reports of intraperitoneal thrombolytic adjunctive therapy for recurrent or persistent PDAP have indicated that these agents may have a role in the treatment of selected patients. Urokinase and st...