cssi/SciSciGPT-SciSciNet huggingface dataset:
Epilepsy surgery in infancy

Surgery for intractable epilepsy is being offered at progressively younger ages, including infancy. The most common causes of catastrophic epilepsy in very young surgical candidates are focal malformations of cortical development and low-grade tumors. Additional causes include Sturge-Weber syndrome, epidermal nevus syndrome, hemimegalencephaly, and prenatal or perinatal infarction. Many infants manifest with focal seizures, whereas some patients have infantile spasms in the setting of a focal epileptogenic lesion. Video electroencepholography, magnetic resonance imaging, and positron emission tomography are critical investigations to explore surgical options. In small series, the percentage of infants free of seizures after surgery was in the range of 60%. This is similar to that seen after epilepsy surgery in older children, adolescents, and adults. However, larger series with long-term follow up will be important. Furthermore, the extensive procedures required in infants for removal of the epileptogenic developmental lesions entail some risk, and should not be offered in the absence of severe epilepsy. Most infant candidates for epilepsy surgery have significant developmental delay. Few data are available, but anecdotal experience suggests that surgical relief of catastrophic epilepsy may result in resumption of developmental progression. For each infant, the timing of surgery must be carefully considered based on full assessment of the relative risks and benefits, derived from a detailed presurgical evaluation.
Speckle interferometry with temporal phase evaluation: Optimization of imaging aperture for in-plane displacement

Summary Recently a new method to measure object shape and deformation using temporal evolution of speckles in speckle interferometry was reported. The principle behind the method is that certain parameter sensitive to shape or deformation is changed continuously and the fluctuations in the intensity of the speckles are recorded in a large number of frames. The phase data for the whole object deformation is then retrieved by inverse Fourier transformation of a filtered spectrum obtained by Fourier transformation of the signal. In this paper a theoretical evaluation of the amplitude of the signal for inplane sensitive interferometer that uses dual beam illumination is presented. It is shown that signal to noise ratio is better when the speckle size is smaller than the pixel size contrary to the normal assumption that the speckle size be matched to the pixel size.
Optimization of spray quenching for aluminum extrusion, forging, or continuous casting

A review of the current understanding of heat transfer from quenched alloy products to water sprays is presented. A numerical example is described to demonstrate how controlled spray cooling of products containing sections of differing thicknesses significantly reduces thermal gradients. A semi-expert computer-aided design (CAD) system is proposed for optimizing the process of spray quenching following extrusion, forging, or continuous casting. A systematic experimental approach to the problem of providing a universal heat transfer data base for the proposed CAD system is presented.
Hormonal action in human cervix—II specific progestogen binding proteins in human cervix

Abstract Progesterone binding activity has been detected in cytosols prepared from human cervical tissue. Cytosols showed high affinity ( K a , 0.2–1 nM −1 ) for progesterone and synthetic progestogens but not for corticosteroids or other steroids (norethindrone, medroxyprogesterone acetate > chlormadinone acetate, progesterone > 5α-pregnane-3,20-dione > norethisterone acetate > 17α-hydroxyprogesterone > cortisol, estradiol). Addition of 49 nM cortisol to the assay buffer permitted measurement of high affinity progesterone binding sites in those cytosols with high concentrations of CBG-like contaminants. The hormone dissociated from the complex with a dissociation rate constant of 6.9 × 10 −5 s −1 (0°C, 18% glycerol). Binding sites exhibited similar K a values throughout the cervix and were found in highest concentration in the region encompassing the columnar epithelium when expressed per mg protein and per g. The concentrations of sites per mg DNA were similar in the columnar epithelium and in the stroma but higher than in the region of the squamous epithelium. Endometrial tissue exhibited higher concentrations of progesterone binding sites than did the corresponding cervix. In both the endometrium and cervix, the mean concentrations expressed per mg protein were significantly higher for proliferative phase than for secretory phase tissues. The corresponding differences in concentration per mg DNA were significant only for cervical cytosols.
Anatomy of a complex computer purchase

Abstract In this paper, we develop guidelines for managers interested in formulating marketing strategies in complex purchasing situations. We examine a complex computer purchase: the adoption of computer integrated manufacturing (CIM). Implementation of the CIM concept requires several specialist vendors to collaborate and develop solutions for each buyer's needs. We show how suppliers can use structural role analysis to understand buyer behavior and develop the multiple alliances that facilitate buyer-seller interaction in complex purchasing situations.
A comparison of non-symmetric entropy-based classification trees and support vector machine for cardiovascular risk stratification

Classification tree-based risk stratification models generate easily interpretable classification rules. This feature makes classification tree-based models appealing for use in a clinical setting, provided that they have comparable accuracy to other methods. In this paper, we present and evaluate the performance of a non-symmetric entropy-based classification tree algorithm. The algorithm is designed to accommodate class imbalance found in many medical datasets. We evaluate the performance of this algorithm, and compare it to that of SVM-based classifiers, when applied to 4219 non-ST elevation acute coronary syndrome patients. We generated SVM-based classifiers using three different strategies for handling class imbalance: cost-sensitive SVM learning, synthetic minority oversampling (SMOTE), and random majority undersampling. We used both linear and radial basis kernel-based SVMs. Our classification tree models outperformed SVM-based classifiers generated using each of the three techniques. On average, the classification tree models yielded a 14% improvement in G-score and a 21% improvement in F-score relative to the linear SVM classifiers with the best performance. Similarly, our classification tree models yielded a 12% improvement in G-score and a 21% improvement in the F-score over the best RBF kernel-based SVM classifiers.
Stability of a hybrid FDTD‐circuit model for on‐chip power‐grid switching analysis

A circuit model for the package-to-chip power grid interface is presented for use in conjunction with the finite-difference time-domain simulation of on-chip power-grid switching. A numerical scheme is proposed for the integration of the hybrid circuit/FDTD model, the stability of which is dictated by the CFL condition for the FDTD grid and thus is independent of the specific values of the circuit elements in the lumped model. Numerical experiments are performed in order to demonstrate the numerical stability of the model and its accuracy. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 535–540, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21401
Temperature-change-based thermal tomography

Thermal properties of biological tissues play a critical role in the study of tumor angiogenesis and the design and monitoring of thermal therapies. To map thermal parameters noninvasively, we propose temperature-change-based thermal tomography (TTT) that relies on relative temperature mapping using magnetic resonance imaging (MRI). Our approach is unique in two aspects: (1) the steady-state body temperature in thermal equilibrium is not restricted to be spatially invariant, and (2) absolute temperature mapping is not required. These two features are physiologically realistic and technically convenient. Our numerical simulation indicates that a (9mm)3 tumor inside a breast phantom can be reliably depicted, assuming moderate temperature mapping accuracy of 0.5°C.
MLHP: A High Heat Flux Localized Cooling Technology for Electronic Substrates

A novel microscale device based on phase change technology is proposed for localized cooling of very high heat flux electronic substrates. Device physics and salient design features are elucidated and a numerical model is developed to predict device performance and optimize the design parameters. The Micro-columnated Loop Heat Pipe (MLHP) consists of evaporator and condenser sections connected by liquid and vapor microchannels, all fabricated on a silicon wafer using MEMS microfabrication techniques. A novel micro-columnated wick is designed to prevent wick dryout to enhance reliability. The MLHP operates using capillary pumping thus requiring no external power and provides enhanced localized cooling capabilities by interfacing directly with a heat producing chip. Recent studies on microscale fluid flow and heat transfer physics in microchannels are implemented in a numerical model to predict the performance of the MLHP. A detailed design optimization study is performed to maximize the device heat flux carrying capacity, which at 1400 W/cm2 is a considerable improvent on all of the existing high heat flux cooling technologies.Copyright © 2008 by ASME
Consumption of dietary supplements and over-the-counter and prescription medications in men participating in the Prostate Cancer Prevention Trial at an academic center

Abstract Objective It is hypothesized that dietary patterns, individual nutrients, and specific prescription and over-the-counter medications may influence prostate carcinogenesis. Little information is available regarding the use of these products among men who are participating in prevention trials targeting prostate cancer. Materials and methods A total of 92 men (mean age 69 years) participating in the Prostate Cancer Prevention Trial (PCPT) at an academic center were asked to bring all nutritional supplements and medications to regularly scheduled study visits. Results Data were collected on 86 of 92 men. We found that 85% of men in the PCPT regularly consumed at least 1 nutritional supplement. The mean (±standard deviation) number of dietary supplements consumed per man was 3.3 ± 3.5 (range 0–21). A multivitamin and multimineral (73%) supplement was the most common product consumed. Single-nutrient supplements regularly consumed included: vitamin E (48%), vitamin C (31%), calcium (24%), and selenium (7%). Of men, 36% reported consumption of herbal products. Medications frequently consumed during the study period that may influence prostate carcinogenesis included nonsteroidal antiinflammatory drugs (57%), antihypertensives (49%), lipid lowering agents (27%), and aspirin (64%). Conclusions Participants in the PCPT at an academic center have a high propensity for dietary supplement use. Many, such as vitamin E and selenium, are hypothesized to influence the risk of prostate cancer. Several of the medications commonly consumed, including aspirin, nonsteroidal antiinflammatory drugs, and statins, are being investigated as chemopreventive agents. Investigators designing prostate cancer chemoprevention trials should consider including detailed documentation of exposure to these products that may influence study outcomes.
Hypocalcemia, hypomagnesemia and hypokalemia during chemotherapy of pulmonary tuberculosis.

Marked hypocalcemia Hypomagnesemia, tetany, hypokalemic alkalosis and hypophosphatemia developed during conventional dose viomycin-pyrazinamide treatment of pulmonary tuberculosis in a middle-aged man. Recovery of renal potassium conservation required nine weeks, but serum calcium and magnesium normalized after three weeks of replacement therapy.
Infrared radiative corrections: Extended treatment applicable to resonant scattering

The calculation of infrared radiative corrections to scattering cross sections, to which a great deal of attention has been devoted in the past, is reconsidered here and carried to a higher order of accuracy within the context of a specific relativistic model. Earlier work, initiated by Low (Phys. Rev. 110, 974 (1958)) and developed further by others, which led to soft-photon approximations for bremsstrahlung amplitudes, is extended to apply to virtual- as well as real-photon emission and absorption processes. As in the earlier work the requirement of gauge invariance plays a central role in the analysis. Evaluation of the new correction term obtained here requires, as input, the physical (on-mass-shell) amplitude for scattering in the absence of radiative interactions. The new term is expected to lead, in most cases, to only small modifications of the results obtained by standard methods; verification of this expectation would provide a useful check on the range of validity of these standard procedures. It is pointed out that for scattering in the neighborhood of a very narrow resonance the new correction term, which properly accounts for rapid variations of the scattering amplitude with energy, could become numerically significant. In an attempt to examine this possibilitymore » in a very preliminary yet quantitative manner the radiative correction terms derived here have been evaluated with the aid of a simple Breit-Wigner representation of the radiation-free scattering amplitude, and some typical results are reported.« less
Does the pattern of postpartum weight change differ according to pregravid body size

OBJECTIVES: To examine differences in the pattern of weight changes during and after pregnancy among four pregravid body mass index (BMI) groups. STUDY DESIGN: Prospective cohort study of women who had two consecutive births at the University of California, San Francisco (UCSF) between 1980 and 1990. MEASUREMENTS: Maternal body weights were available before conception and delivery, and at 6 weeks postpartum for the first (index) pregnancy, and before conception for the second study pregnancy. Height and two pregravid weights were self-reported. Weights at delivery and 6 weeks postpartum were measured. Net delivery weight was defined as delivery weight minus infant birth weight. Three non-overlapping sequential weight changes were constructed: (1) net gestational gain (net delivery weight minus pregravid weight at the index pregnancy); (2) early net postpartum weight change (6-week postpartum weight minus net delivery weight); and (3) late postpartum weight change (pregravid weight at the second pregnancy minus 6-week postpartum weight). SUBJECTS: A total of 985 healthy women (age 18–41 y) from four race/ethnicity groups (Asian, Hispanic, black and white) who had a singleton, full-term, live birth for the index pregnancy followed by a second consecutive birth. RESULTS: Four race/ethnicity groups were combined (no interaction) to contrast average weight changes among pregravid BMI groups. Means adjusted for eight covariates (parity, race/ethnicity, education, mode of delivery, smoking, hypertension of pregnancy, age, height) and time intervals were not altered appreciably. Early net postpartum weight losses were similar for all pregravid BMI groups. Late (median of 2 y) postpartum weight losses were 4 kg higher in the low and average BMI groups compared with the highest BMI group. About half of the net gestational gain was lost by 6 weeks postpartum, and the percentage that was lost decreased over time. CONCLUSIONS: This study suggests that early postpartum weight loss does not vary by maternal pregravid BMI group, but late postpartum weight change does. Serial weight measurements are needed in epidemiologic studies to differentiate retention of gestational gain from weight gain during the late postpartum period.
The influence of vitamin C on antipyrine pharmacokinetics in elderly men

The influence of vitamin C on the pharmacokinetics of antipyrine was investigated in eleven elderly men aged 65-74. Antipyrine (15 mg kg-1) was administered intravenously on three separate occasions over a 7-week period: (a) before dietary vitamin C restriction, (b) after approximately 5 weeks of dietary vitamin C restriction, and (c) after 2 weeks of vitamin C supplementation (500 mg orally twice daily). The mean plasma and leucocyte vitamin C levels (+/- S.D.) before vitamin C restriction were 1.26 +/- 0.31 mg dl-1 and 26.6 +/- 6.7 micrograms 10(-8) leucocytes, respectively. These values decreased and then increased significantly following vitamin C restriction and supplementation, respectively. The mean plasma half-life of antipyrine was 10.2 h and the mean plasma clearance was 2.561 h-1 1.73 m-2 before vitamin C restriction. No significant changes in the clearance, volume of distribution, or half-life of antipyrine occurred during the study, indicating that short-term alterations in vitamin C intake do not affect the pharmacokinetics of antipyrine in elderly males.
Algal-Available Phosphorus in Suspended Sediments from Lower Great Lakes Tributaries

Suspended sediments collected from five tributaries to the lower Great Lakes were chemically analyzed for several forms of phosphorus and bioassayed under aerobic conditions to measure the release of algal-available phosphorus. The bioassay data for all samples, interpreted through a first-order model of available phosphorus release, showed an average of 21.8 percent of the total paniculate phosphorus ultimately was available to Selenastrum capricornutum, and available phosphorus was released at an average rate of 0.154 day−1. Amounts of available phosphorus varied considerably between tributaries with the Ohio tributaries (Maumee, Sandusky, and Cuyahoga Rivers) showing generally greater amounts than those in New York (Cattaraugus and Genesee Rivers). Non-apatite fractions of inorganic phosphorus (base-, and reductant-extractable) correlated well with levels of available phosphorus in the suspended sediment samples; however, the first-order release coefficients showed little dependency on the paniculate phosphorus characteristics. The results indicate that prediction of phosphorus dynamics in the lower Great Lakes may be made with greater accuracy than current models allow by considering available phosphorus to be released from an ultimately-available fraction of the total paniculate phosphorus during residence in the water column.
The NAD+-Dependent SIRT1 Deacetylase Translates a Metabolic Switch into Regulatory Epigenetics in Skeletal Muscle Stem Cells

Stem cells undergo a shift in metabolic substrate utilization during specification and/or differentiation, a process that has been termed metabolic reprogramming. Here, we report that during the transition from quiescence to proliferation, skeletal muscle stem cells experience a metabolic switch from fatty acid oxidation to glycolysis. This reprogramming of cellular metabolism decreases intracellular NAD+ levels and the activity of the histone deacetylase SIRT1, leading to elevated H4K16 acetylation and activation of muscle gene transcription. Selective genetic ablation of the SIRT1 deacetylase domain in skeletal muscle results in increased H4K16 acetylation and deregulated activation of the myogenic program in SCs. Moreover, mice with muscle-specific inactivation of the SIRT1 deacetylase domain display reduced myofiber size, impaired muscle regeneration, and derepression of muscle developmental genes. Overall, these findings reveal how metabolic cues can be mechanistically translated into epigenetic modifications that regulate skeletal muscle stem cell biology.
Hydroxyapatite-Coated Titanium-Based Preparation of Biomaterials by RF Magnetron Sputtering

Hydroxyapatite (HAP) coatings are widely used to improve the biocompatibility of the substrate. In this paper, Ti-based HAP coatings were prepared by RF magnetron sputtering method, and the coatings’ structure and composition were analyzed by SEM，EDX and IR spectroscopy. When the sputtering conditions were 290 W and 120-180 min, the nano-HAP surface coatings had formed on the surface of Ti-based. The average size of grain was 48nm, and the elemental composition of the coatings was consistent with the HAP coatings. The coating thickness was 513±15~985±25 nm, Ca/P=1.51±0.03~1.84±0.04. After 90 days following the day when Ti-based HAP materials were implanted, bone tissues had covered the surface of the coatings, osteoclasts could be seen, and the bond strength of the coatings had not changed significantly. HAP coatings prepared by the method of RF magnetron sputtering have excellent bioactivity and stability.
Effect of retorted-oil shale leachate on a blue-green alga (Anabaena flos-aquae)

Oil shale reserves in Piceance Creek and the White River, Colorado, contain retorted-shale piles which may pollute th eground water through leaching. Bioassay experiments were carried out to determine the effects of leachates on algae, particularly ANABAENA FLOSAQUAE and SCENEDESMUS. Tests were done to establish inhibitionary concentrations of the leachates from various sources of spent shale. Retorted-shale leachates had major effects on the algae papulations at a 40% concentration, minor effects at 8%, and no effects at 0.4%. Discrepancies between experimental results and actual retorted-shale piles are dixcussed. (JMT)
Functional and Structural Characterization of Factor Xa Dimer in Solution

Previous studies showed that binding of water-soluble phosphatidylserine (C6PS) to bovine factor Xa (FXa) leads to Ca2+-dependent dimerization in solution. We report the effects of Ca2+, C6PS, and dimerization on the activity and structure of human and bovine FXa. Both human and bovine dimers are 106- to 107-fold less active toward prothrombin than the monomer, with the decrease being attributed mainly to a substantial decrease in kcat. Dimerization appears not to block the active site, since amidolytic activity toward a synthetic substrate is largely unaffected. Circular dichroism reveals a substantial change in tertiary or quaternary structure with a concomitant decrease in α-helix upon dimerization. Mass spectrometry identifies a lysine (K270) in the catalytic domain that appears to be buried at the dimer interface and is part of a synthetic peptide sequence reported to interfere with factor Va (FVa) binding. C6PS binding exposes K351 (part of a reported FVa binding region), K242 (adjacent to the catalytic triad), and K420 (part of a substrate exosite). We interpret our results to mean that C6PS-induced dimerization produces substantial conformational changes or domain rearrangements such that structural data on PS-activated FXa is required to understand the structure of the FXa dimer or the FXa-FVa complex.
A petrologic and ion microprobe study of a Vigarano Type B refractory inclusion: Evolution by multiple stages of alteration and melting

A Type B Ca-, Al-rich 6-m-diam inclusion (CAI) found in the Vigarano C3V chondrite was inspected using optical and scanning electron microscopies and ion microprobe analyses. It was found that the primary constituents of the CAI inclusion are (in percent), melilite (52), fassaite, (20), anorthite (18), spinel (10), and trace Fe-Ni metal. It is noted that, while many of the properties of the inclusion indicate solidification from a melt droplet, the Al-26/Mg-26 isotopic systematics and some textural relationships are incompatible with single-stage closed system crystallization of a homogeneous molten droplet, indicating that the history of this inclusion must have been more complex than melt solidification alone. Moreover, there was unusually high content of Na in melilite, suggesting that the droplet did not form by melting of pristine high-temperature nebular condensates.
A prophylactic usage of systematic desensitization

This investigation focused on the “blind” application of systematic desensitization to common fears as a means for preventing the occurrence of potential, and highly probable anxiety. Two groups of 10 student volunteers were matched on the basis of their scores on the Taylor Manifest Anxiety Scale. One group, the placebo control group (PC), received eight sessions of “systematic desensitization” using an anxiety hierarchy of irrelevant scenes. The experimental group (ET) received eight treatment sessions in the first half of each of which was devoted to desensitization to live snakes, and the second half to desensitization to public speaking. At the end of desensitization, all subjects were tested for fear reactivity to snakes and public speaking. In both areas the control group's scores were significantly higher (P < 0·05) than those of the experimental group's.
Hydrogen Production via the Iron/Iron Oxide Looping Cycle

The iron/iron-oxide looping cycle has the potential to produce high purity hydrogen from coal or natural gas without the need for gas phase separation: Hydrogen is produced from steam oxidation of iron or Wustite yielding primarily Magnetite; Magnetite is then reduced back to iron/Wustite using syngas (CO+H2 ). A system model has been developed to identify favorable operation conditions and process configurations. Process configurations for three distinct temperature ranges, (i) 500–950 K, (ii) 950–1100 K, and (iii) 1100–1200 K have been developed. The energy content of high temperature syngas from conventional coal gasifiers is sufficient to drive the looping process throughout the temperature range considered. Temperatures around 1000 K are advantageous for both the hydrogen production step and the iron oxide reduction step. Simulations of a large number of subsequent cycles indicate that quasi-steady operation is reached after approximately 5 cycles. Comparison of simulations and experiments indicate that the process is currently limited by chemical kinetics at lower temperatures. Therefore, product recirculation should be used for a scaled-up process to increase reactant residence times while maintaining sufficient fluidization velocity.Copyright © 2011 by ASME
Americium interaction with calcite and aragonite surfaces in seawater

Observations of the distribution of 241Am in the marine environment indicate that Am has a high affinity for solid surfaces. The adsorption of Am onto calcite and aragonite surfaces from seawater and related solutions has been studied, in order to establish the interaction of Am with a major component of many marine sediments. Results indicate that Am is rapidly and strongly adsorbed. This occurs even when both dissolved Am concentrations and solid to solution ratios are low. The minimum value for KD determined is 2 × 105. Measurements of reaction kinetics established that Am is adsorbed from seawater at 40 times the rate per unit surface area on synthetic aragonite that it is on synthetic calcite. Approximately 15% of the difference is attributable to epitaxial influences, with the remainder being due to enhanced site competition by Mg on calcite relative to aragonite. The adsorption rate is first order with respect to Am concentration, but follows approximately the square root of the solid surface area to solution volume ratio. Adsorption rate of Am on biogenic aragonite and Mg-calcites are, within a given particle size range, close to equal. It is not possible to normalize these adsorption rates to surface area due to the differing microporous structure of biogenic carbonates. The Am adsorption rates on a shallow water calcium carbonate-rich sediment gave results which were predicted from, its mineralogie mixture of components.
Numerical calculation of the effective second-order nonlinear coefficient along collinear phase-matching directions inside nonlinear crystals in three-wave interaction

In this work, we present the first numerically calculated values of the second-order nonlinear coefficient D/sub eff/ along collinear phase-matching directions inside the biaxial crystal. We have demonstrated our results using KTP in optical parametric generation. Our results are in agreement with recent experimental data. The theoretical approach presented here is a simple and generalized method which encompasses H. Ito's and B. Wyncke's works.
The 260 nm absorption spectrum of benzene: Remeasured band positions and refined assignments

Abstract The positions and intensities of most of the band maxima in the 1 B 2u ← 1 A 1g absorption system of benzene vapor have been remeasured at 300K. Particular attention has been given to the measurement of the positions of component maxima which are present on account of vibrational angular momentum splitting. Weak O2 absorptions included in the original listings of benzene band maxima have been identified. Assignments of the benzene maxima are given. They offer some revision and substantial extension of previous assignments. The general basis and specific details of assignments are given in papers II and III.
Glyceryl trinitrate (nitroglycerin) and the organic nitrates. Choosing the method of administration.

Nitrate usage worldwide is on the increase as the indications for therapy expand. Present indications for nitrate therapy include chronic stable angina pectoris, unstable angina pectoris, complications of acute myocardial infarction, and ‘unloading’ therapy for acute and chronic congestive heart failure. Nitrates are also being used in the operating suite by anaesthesiologists to control systolic blood pressure during various surgical procedures. New nitrate delivery systems have recently become available which provide considerable dosing flexibility, further increasing the interest in this group of compounds. The dominant action of nitrates is a direct effect on vascular smooth muscle, producing vasodilation of the veins and arteries. These drugs decrease myocardial work by lowering systolic blood pressure, systemic vascular resistance, and reducing intracardiac dimensions. In addition, nitrates have a potent effect on cardiac preload as a result of systemic venodilatation. There is also some evidence that nitrates exert direct effects on the coronary circulation (vasodilatation of coronary arteries and coronary collateral vessels, and direct atherosclerotic stenosis dilatation). These actions may play a role in relieving myocardial ischaemia. Adverse sequelae of nitrate therapy are well known and serious adverse reactions are uncommon. Headache and dizziness are the most frequent side effects. Nitrate tolerance is a definite problem — present evidence indicates that long acting formulations, high doses, or frequent dosing regimens are particularly likely to induce vascular tolerance to nitrates. Consequently, provision of a nitrate- free interval has taken on increasing significance as a strategy to avoid tolerance. Nitrate delivery systems are numerous. Although availability varies from country to country, in most countries there are a wide variety of formulations of glyceryl trinitrate (nitroglycerin) available, including sublingual and oral tablets, oral spray, topical ointment as well as discs or patches for transdermal administration, a transmucosal tablet and an intravenous formulation. Similar formulations of isosorbide dinitrate, except buccal tablets, are available in some countries. Isosorbide 5- mononitrate, a potent metabolite of isosorbide dinitrate, is achieving increasing popularity as an antianginal drug. Optimum nitrate therapy requires a good understanding of the properties of the various formulations, particularly onset and duration of action and propensity to induce tolerance. Patient preference is also an important factor in making a final choice of a formulation, particularly for angina prophylaxis where several preparations show approximately equivalent efficacy.
Activation-induced changes in alternate splice acceptor site usage

Abstract An AGCAG motif at 3′ splice acceptor sites in a diverse set of genes creates alternate in-frame splice acceptor sites that produce alternate protein isoforms differing by a single amino acid. Among a group of over 12,000 EST-verified splice acceptor sites, only 74 genes were identified that contained the AGCAG motif, comprising about 0.7% of the total. In some cases the location of the single amino acid insertion occurs in a region with the potential to affect protein function. Analysis of cDNA from five different human genes of immunologic interest that contain the AGCAG motif, CD3ζ, CD79B, PLCγ1, CD19, and CD32B (FcγRIIB), confirms that each gene encodes the two predicted splice variants. Variations occur in the splice variant ratio in all five of the genes tested during T and B cell activation, suggesting that the ratio is regulated by the cellular activation state. These results suggest that activation-induced variation in mRNA splicing may represent a mechanism for functional modulation of these proteins.
Carcinogens and carcinogenesis enhancers

The concept that chemical agents may lead to enhancement of carcinogenesis, rather than to its complete induction, is explored to explain the inexact correlation between carcinogen prescreening tests and the results of whole animal bioassays. It is suggested that carcinogenesis-enhancing agents are non-genotoxic chemicals which are positive in animal carcinogenesis bioassays. The importance of understanding the mechanisms of action of carcinogenesis-enhancing agents is emphasized.
The eosinophilia-myalgia syndrome

A seemingly new illness was first described in the United States in late 1989, when physicians in New Mexico reported the occurrence #of generalized myalgia and eosinophilia in three women, each of whom had a prior history of ingesting the amino acid, L-tryptophan.’ The illness, which has been linked to the ingestion of L-tryptophan containing trace amounts of chemical contaminants reached epidemic proportions in late 1989, and it quickly subsided when L-tryptophan containing products were recalled. This illness, now known as the eosinophilia -myalgia syndrome (EMS), was frequently complicated by the occurrence of sclerodermalike hardening of the skin and subcutaneous tissues and, thus, may be added to a growing list of environmental or toxin exposures implicated in the pathogenesis of sclerodermatous disorders. EMS shares many features with diffuse fasciitis with eosinophilia (DFE or Shulman’s disease),2 as well as with the toxic oil syndrome (TOS), another sclerodermalike disease which occurred as an epidemic in 1981, affecting nearly 20,000 individuals in Spain.3 The study of EMS and related conditions is important, not only for the sake of public health, but also for the insight which may be gained for better understanding of systemic sclerosis (SSc) and other fibrosing cutaneous processes.
Ca2+ metabolism in yeast cells and mitochondria

Abstract 1. 1. Ca 2+ in the culture medium stimulates only slightly the growth and respiration of Saccharomyces cerevisiae . 2. 2. Neither energy-linked Ca 2+ transport nor high-affinity Ca 2+ binding occur in mitochondria isolated from Saccharomyces cerevisiae or from Torulopsis utilis . 3. 3. Metabolism-independent, low-affinity binding of Ca 2+ does, however, occur in mitochondria isolated from both yeasts. The concentration of these sites varies between 40 and 50 nmoles per mg of mitochondrial protein. Their affinity for Ca 2+ is rather low ( K m = 10–20 μ M). 4. 4. Mitochondria of Saccharomyces cerevisiae contain about 10 nmoles of endogenous Ca 2+ per mg of mitochondrial protein, which is bound or sequestered in a very stable manner. 5. 5. The respiration of mitochondria from Saccharomyces cerevisiae is stimulated by valinomycin in the presence of KCl, suggesting that energy-linked transport of K + occurs. 6. 6. The results show that energy-linked Ca 2+ transport is not a universal attribute of intact mitochondria from all species. Since the yeast cells lack high-affinity Ca 2+ binding capacity, they may lack a specific Ca 2+ carrier. The basic energy-dependent cation pump may however be present in these mitochondria, since they can transport K + in the presence of valinomycin.
Hydrologic, Riparian, and Agroecosystem Functions of Traditional Acequia Irrigation Systems

ABSTRACT Traditional cultures in arid landscapes of the southwestern United States and northern Mexico developed irrigation systems to irrigate floodplain valleys along streams and rivers. Many of these traditional irrigation systems, referred to as acequias, continue to be used today. Population growth in the region is creating pressures to convert agricultural land and irrigation water to urban and other uses. Unique hydrologic features of the acequia systems suggest that, beyond providing crop irrigation, they may provide additional valuable hydrologic, riparian, and agroecosystem functions worth maintaining. We investigated in detail the seepage and the groundwater response to seepage from a traditional acequia irrigation ditch along the Rio Grande in north-central New Mexico. We found that 16% of ditch flow seeps into the ditch bed and banks. Groundwater levels near the ditch and midway between the ditch and the river rise 1 m or more within three to four weeks following the start of the irrigation s...
Induced deactivation of naphthalene triplets by cis-piperylene.

— Interaction of naphthalene triplets with trans-piperylene leads to triplet energy transfer with unit efficiency. When cis-piperylene is used as a quencher of naphthalene triplets, the efficiency of triplet energy transfer is found to be 0–76 ± 004. The rest of the quenching encounters in this case lead to deactivation of naphthalene triplets, without energy transfer.
The changing faces of children with cleft lip and palate

There have been major advances in the care of children born with cleft lip and palate. Dr. John B. Mulliken makes the case that every newborn with a cleft lip should be sent to a regional center.
Development and characterization of two porcine monocyte-derived macrophage cell lines

Cell lines CΔ2+ and CΔ2− were developed from monocytes obtained from a 10-month-old, crossbred, female pig. These cells morphologically resembled macrophages, stained positively for α-naphthyl esterase and negatively for peroxidase. The cell lines were bactericidal and highly phagocytic. Both cell lines expressed the porcine cell-surface molecules MHCI, CD11b, CD14, CD16, CD172, and small amounts of CD2; however, only minimal amounts of CD163 were measured. The lines were negative for the mouse marker H2Kk, bovine CD2 control, and secondary antibody control. Additionally, cells tested negative for Bovine Viral Diarrhea Virus and Porcine Circovirus Type 2. Therefore, these cells resembled porcine macrophages based on morphology, cell-surface marker phenotype, and function and will be useful tools for studying porcine macrophage biology.
High-Energy π 0 Photoproduction from Hydrogen with Unpolarized and Linearly Polarized Photons

We have completed measurements of the differential cross section for $\ensuremath{\gamma}+p\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}+p$, and the asymmetry with polarized photons, for incident photon energies from 4 to 18 GeV and momentum transfers between $t=\ensuremath{-}0.1 \mathrm{and} \ensuremath{-}1.4$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$. The experiment was performed at the Stanford Linear Accelerator Center, using the SLAC 1.6-GeV/c spectrometer to analyze protons recoiling from a hydrogen target. For the cross-section measurements a normal collimated bremsstrahlung beam was used. For the asymmetry measurements the polarized photons were produced by coherent bremsstrahlung from a diamond crystal, and a coincidence was required between the recoil proton and one of the ${\ensuremath{\pi}}^{0}$ decay photons in a shower counter.
Reliability of segmented edge seal ring for RF devices

RF devices are sensitive to noise coupling between devices. One source of coupling is the edge seal ring. We propose using a segmented guard ring to reduce coupling between devices. We demonstrate that the segmented guard ring is reliable for a 0.18 µm RF technology.
Subtraction computed tomographic angiography: use of pre-contrast images for calcification removal

Arterial stenoses may be obscured by calcified atherosclerotic plaque in computed tomographic angiography (CTA). A technique of subtraction computed tomographic angiography (sCTA) for calcification removal is proposed and evaluated in a preliminary manner. In the proposed sCTA method, the examination includes a pre-contrast computed tomogram (pcCT) and a CTA. The pcCT is performed using the CTA scan protocol. Subtraction of the registered pcCT from the CTA is performed after calcifications in the pcCT are registered to the CTA using a piecewise-rigid transformation model. The registration is based on a maximum-cancellation cost-function. Points at the boundary of the artery in the CTA are given a greater weight in the cost function than those towards the center of the artery. sCTA was evaluated using a calcified-artery phantom whose dimensions approximate those of the superficial femoral artery. The phantom represented both calcified plaque surrounding stenotic segments of the artery. pcCT and CTA's were obtained on a 4-multidetector-row CT system with 1.25-mm slice thickness and 0.7-mm in-plane resolution. The phantom was slightly displaced between the pcCT and the CTA. sCTA closely resembled a gold-standard image of the phantom that was obtained with the calcification material removed. The sCTA accurately demonstrated the degree of stenosis and artifacts in the sCTA were minimal. This study demonstrates in a preliminary manner that sCTA is feasible.
Comparison of intravenous digital subtraction angiography to conventional aortography in patients with abdominal aortic aneurysm

Evaluation of intravenous digital subtraction angiography (IV DSA) in patients with abdominal aortic aneurysm was performed by obtaining catheter aortograms immediately before DSA studies in ten patients. Diagnostic images were obtained in nine of ten digital subtraction examinations. Although repeat injections were necessary in six DSA and three conventional aortography cases for adequate imaging of both cephalad and caudal extension of the aneurysm, average contrast dose was 53 cc (62 cc in standard catheter studies). Renal artery stenosis was diagnosed by DSA in two of three vessels, multiple renal arteries were demonstrated by both modalities in two cases. Digital subtraction and conventional aortographic findings were proved at surgery. Intravenous DSA was shown to be useful in the preoperative evaluation of patients with abdominal aortic aneurysm.
Reassessing Gentrification: Measuring Residents’ Opinions Using Survey Data

Qualitative studies have focused on the proponents and the opponents to gentrification but have not provided a clear picture of the opinions of a truly representative sample of residents. This article uses probability sampling and a large sample size to examine residents in two gentrifying neighborhoods in Portland, Oregon. The results suggest that the majority of residents—including owners and renters, Whites and minorities, newcomers and longtime residents, those college educated and not—like how their neighborhood has changed and think it will improve even more in the future. However, regression analysis reveals that renters and longtime Black residents are less likely to view these changes positively.
Introduction: Access Services at Penrose Library, University of Denver: A Case Study

The endeavors of the Access Services Department of University of Denver's (DU) Penrose Library is introduced as a six-year case study. The purpose, mission, and functions of the department are described.
Using colloidal gold nanoparticles for studies of laser interaction with defects in thin films

A model thin-film system based on SiO2 coating with artificially introduced gold nanoparticles was investigated for the mechanism of 351-nm, pulsed-laser-radiation interaction with well-characterized nanoabsorbers. Damage morphology, represented by craters, provides strong evidence of the important role of the melting and vaporization processes. Measured crater volumes and numerical estimates based on them suggest that crater formation cannot proceed through laser-energy absorption confined within the particle. It instead starts in the particle and then, due to energy transfer, spreads out to the surrounding matrix during the laser pulse.
Hypotension: Preventing the Fall

Childbearing Poster Presentation Purpose for the Program The staff in the labor and delivery (L&D) unit at Baylor University Medical Center noticed an increased incidence of hypotension after epidural placement, which required ephedrine for treatment. Data collection began to determine if the perception was accurate and if there were recognizable patterns. Initial surveys that evaluated knowledge regarding hypotension were given to various nurses on each shift. Additionally, 69 retrospective random chart audits were conducted, which evaluated baseline blood pressure before and after epidural placement and evaluated the use of ephedrine to treat hypotension. Our initial data suggested a staff knowledge deficit and a postepidural hypotension rate of 22.67%. Proposed Change The L&D Comprehensive Unit‐Based Safety Program (CUSP) felt this data reflected a quality improvement opportunity. Based on our process modeling flow chart and fishbone diagram, we developed a goal to reduce postepidural hypotension in the obstetric patient population by 5% with the implementation of nursing education and clarification of order sets. Implementation, Outcomes, and Evaluation To correct the knowledge deficit and inconsistent use of order sets, we developed and provided educational in‐services. The in‐services focused on potential exaggerating or precipitating factors and the prevention and corrective measures of postepidural hypotension. We also focused on improving communication between registered nurses (RNs) and anesthesiologists, empowering the RNs to ask more questions regarding procedure type, medications given, timing, and amount of preload versus co‐load. Additionally, our documentation system was revised to facilitate improved documentation of interventions, including intravenous fluid bolus timing and amount. Biweekly random chart audits were performed to evaluate progress and percentage of hypotension. Through standardized education and improved collaboration between RNs and anesthesiologists, Baylor University Medical Center's hypotension rate in the obstetric population decreased from 22.67% to 8%. Implications for Nursing Practice Though literature states that hypotension affects up to 80% of parturient women, we aim to decrease the incidence of maternal/fetal response and promote safe passage with efforts focused on prevention, recognition, and early intervention,
A parasitics extraction and network reduction algorithm for analog VLSI

A transmission line model for the extraction of circuit parasitics in integrated circuits is presented. This model is shown to give a better account of the DC and aC characteristics of interconnects than models incorporating exclusively the R or C components. A network-reduction technique that is used to simplify the extracted RC network at user-specified accuracies to manageable complexities, especially for large VLSI circuits, is also discussed. The model and circuit reduction algorithms are applied to practical sample circuits and results of simulations illustrating the reduction in circuit complexity and the degree of modeling accuracy by these methods are given. >