cssi/SciSciGPT-SciSciNet huggingface dataset:
Effect of an electric field on the luminescence of GaAs quantum wells

Low-temperature photoluminescence (PL) measurements have been performed in narrow GaAs-${\mathrm{Ga}}_{1\ensuremath{-}x}{\mathrm{Al}}_{x}\mathrm{As}$ quantum wells subject to an electric field perpendicular to the well plane. At low fields the PL spectra show two peaks associated, respectively, with exciton and free-electron-to-impurity recombination. With increasing field the PL intensity decreases, with the excitonic structure decreasing at a much faster rate, and becomes completely quenched at a field of a few tens of kV/cm. This is accompanied by a shift in the peak position to lower energies. The results are interpreted as caused by the field-induced separation of carriers and modification of the quantum energies. Variational calculations performed for isolated, finite quantum wells explain qualitatively the experimental observations.
Aluminum Does Not Accumulate in Teenagers and Adults on Prolonged Parenteral Nutrition Containing Free Amino Acids

Prolonged total parenteral nutrition (TPN) with solutions containing hydrolyzed casein has been associated with aluminum accumulation in patients with bone disease. We investigated the effects of free amino acids in TPN solution on plasma, urine, and bone aluminum in six patients, five of whom had symptoms of bone disease or documented demineralization. No evidence of aluminum accumulation was found. TPN with free amino acids, containing 42 micrograms aluminum per liter or less, does not lead to aluminum loading in adolescents or adults.
Effect of blast furnace slag grades on fly ash based geopolymer waste forms

Abstract Ground granulated blast furnace slags (GGBFSs) of grades 80, 100 and 120 were investigated for high waste loading fly ash based geopolymer waste forms. Samples were prepared at a fixed fly ash/GGBFS mass ratio of 5/3, using an activating solution prepared from concentrated Hanford secondary waste (HSW) simulant. The fresh pastes were subjected to isothermal conduction calorimetry and Vicat setting time measurements, and the cured waste forms were characterized by compressive strength test, XRD and SEM/EDS analyses, as well as the TCLP leaching test. The results show that GGBFS of higher grade generated more hydration heat, yet not definitely led to higher compressive strength or shorter setting times, suggesting that the GGBFS grading index established for cement industry may not be simply introduced to geopolymer application. It was also found that the reactivity potential of high grade GGBFS in fly ash based geopolymer might be better exploited at enhanced SiO 2 /Al 2 O 3 and SiO 2 /CaO ratios. Except for rhenium, which is not regulated in TCLP, all heavy metals and hazardous elements in the HSW simulant were effectively immobilized by the geopolymer waste forms. However, effect of different GGBFS on heavy metals and hazardous elements fixation depended on different metals and elements.
CYP2C9*8 Is Prevalent Among African-Americans: Implications for Pharmacogenetic Dosing

Aims Although the frequencies of pharmacogenetic variants differ among racial groups, most pharmacogenetic algorithms for genotype-guided warfarin dosing only include two CYP2C9 alleles (*2 and *3) and a single VKORC1 allele (g.-1639G>A or g.1173C>T) commonly found among Caucasians. Therefore, this study sought to identify other CYP2C9 and VKORC1 alleles important in warfarin dose variability and to determine their frequencies in different racial and ethnic groups. Materials & methods The CYP2C9 and VKORC1 genes were sequenced in selected sensitive ( 49 mg/week) individuals with discrepant therapeutic and algorithm-predicted warfarin doses based on prior CYP2C9 and VKORC1 genotyping. The CYP2C9 and VKORC1 allele frequencies were determined in healthy, racially self-identified blood donors. Results Sequencing identified an African-American male with a lower than predicted therapeutic warfarin dose (14.4 mg/week), previously genotyped as CYP2C9*1/*1, who was homozygous for CYP2C9*8 (c.449G>A; p.R150H). Genotyping 600 African-American alleles identified CYP2C9*8 as their most frequent variant CYP2C9 allele (0.047), and the combined allele frequency of CYP2C9*2, *3, *5, *6, *8 and *11 was 0.133. Given most warfarin pharmacogenetic dosing algorithms only include CYP2C9*2 and *3, the inclusion of CYP2C9*8 alone could reclassify the predicted metabolic phenotypes of almost 10% of African-Americans, or when combined with CYP2C9*5, *6 and *11, more than 15%. In addition, the African-American VKORC1 g.-1639A allele frequency was 0.108 and three g.1331G>A (p.V66M) carriers were identified. Conclusions CYP2C9*8 is prevalent among African-Americans ( approximately 1 in 11 individuals). Thus, in this racial group, the incorporation of CYP2C9*8 into genotyping panels may improve dose prediction of CYP2C9-metabolized drugs, including warfarin.
Secular trends in cardiovascular disease mortality, incidence, and case fatality rates in adults in the United States

Purpose To assess the effects of changes in cardiovascular disease incidence and case fatality rates on secular trends in mortality in the U.S. population between 1971–1982 and 1982–1992. Methods Using data from the first National Health and Nutrition Examination Survey Epidemiologic Follow-up Study, two cohorts (10,869 subjects in the 1971–1982 cohort and 9774 in the 1982–1992 cohort) of participants aged 35 to 74 years were created. Baseline medical history questionnaires were administered in 1971–1975 and 1982–1984, with follow-up interviews, hospital record reviews, and death certificate searches conducted in 1982–1984, 1986, 1987, and 1992. Results Between 1971–1982 and 1982–1992, age-standardized cardiovascular disease mortality declined from 79.1 (95% confidence interval [CI]: 75.2 to 83.0) to 53.0 (95% CI: 49.5 to 56.5) per 10,000 person-years, while cardiovascular disease incidence rates decreased from 293.5 (95% CI: 284.5 to 302.4) to 225.1 (95% CI: 216.6 to 233.5) per 10,000 person-years. The 28-day case fatality rate for cardiovascular disease declined from 15.7% (95% CI: 14.5% to 16.8%) to 11.7% (95% CI: 10.3% to 13.0%). After adjustment for age, sex, and race, rates were 31% lower for cardiovascular disease mortality, 21% lower for incidence, and 28% lower for 28-day case fatality in the 1982–1992 cohort than in the 1971–1982 cohort (each P Conclusion The decrease in cardiovascular disease mortality between 1971–1982 and 1982–1992 was due to declines in both the incidence and case fatality rates in this national sample. These findings suggest that both primary and secondary prevention and treatment contributed to the decline in cardiovascular disease mortality in the United States.
Maternal race, demography, and health care disparities impact risk for intraventricular hemorrhage in preterm neonates

Objective To determine whether risk factors associated with grade 2-4 intraventricular hemorrhage (IVH) differs between infants of African ancestry and white infants. Study design Inborn, appropriate for gestational age infants with birth weight 500-1250 g and exposure to at least 1 dose of antenatal steroids were enrolled in 24 neonatal intensive care units. Cases had grade 2-4 IVH and controls matched for site, race, and birth weight range had 2 normal ultrasounds read centrally. Multivariate logistic regression modeling identified factors associated with IVH across African ancestry and white race. Results Subjects included 579 African ancestry or white race infants with grade 2-4 IVH and 532 controls. Mothers of African ancestry children were less educated, and white case mothers were more likely to have more than 1 prenatal visit and multiple gestation ( P ≤ .01 for all). Increasing gestational age ( P = .01), preeclampsia ( P P = .02), cesarean delivery ( P P = .01) were associated with decreased risk for IVH. Chorioamnionitis ( P = .01), 5-minute Apgar score P P P P = .02). Among white infants, multiple gestation was associated with increased risk ( P P Conclusion The risk for IVH differs between infants of African ancestry and white infants, possibly attributable to both race and health care disparities.
Thrombolysis in the Management of Acute Myocardial Infarction and Unstable Angina Pectoris

Thrombolytic therapy has recently gained ascendance as an accepted form of treatment for acute myocardial infarction. Since the majority of patients with acute infarction have an occlusive coronary thrombus, plasminogen activators administered to these patients generate plasmin that proteolysis the fibrin elements of the thrombus and thereby reestablishes coronary patency. In addition to the conventional agents streptokinase and urokinase, newer, more fibrin-selective plasminogen activators are currently available for use or study, including tissue plasminogen activator and pro-urokinase. In acute myocardial infarction, the agents that have been studied most extensively are streptokinase and tissue plasminogen activator. Among the major recent studies of the use of these activators, several important observations have been made, including the need for administration of agent within 3 hours of the onset of pain, the efficacy of the intravenous route of administration, significant reduction in mortality with early administration, and significantly improved left ventricular function with early administration. Haemorrhagic complications remain a problem, but with judicious dosing their incidence can be kept to a minimum. Early studies in patients with unstable angina suggest that plasminogen activators may also have a role in the management of this clot-dependent disorder.
Hydroxypyridinone extraction agents for Pu(IV)

Abstract Twelve different extraction agents, based on the hydroxypyridinone (HOPO) chelating moieties 3,2‐HOPO, 3,4‐HOPO, and 1,2‐HOPO, have been synthesized and characterized for their ability to remove Pu(IV) from nitric acid solutions. Most of these, in particular those based on 1,2‐HOPO, displayed very rapid extraction kinetics and extracted Pu(IV) with large distribution ratios. They were also highly effective in removing Pu(IV) from solutions containing high concentrations of Fe(III) or ethylenediaminetetraacetic acid (EDTA). Stripping the bound Pu(IV) from the chelate complex proved challenging, as only ∼40% was removed even with concentrated (15.8 M) nitric acid.
Sporulation and Germination Gene Expression Analysis of Bacillus anthracis Sterne Spores in Skim Milk under Heat and Different Intervention Techniques

To investigate how B. anthracis Sterne spores survive in milk under heat (80 degrees C, 10 min), pasteurization (72 degrees C, 15 s), microfiltration, and pasteurization and microfiltration, the expression levels of genes related to sporulation and germination were tested using real-time PCR assays. Twenty-seven sporulation- and germination-related genes were selected for the target genes. Our results demonstrated that gene expression levels were altered by heat and microfiltration whereas the pasteurization and pasteurization and microfiltration resulted in less alteration of gene expression. Heat activated and inhibited both sporulation- and germination-related genes, suggesting that bacterial spores underwent different molecular mechanism for heat treatments. Our results may provide some insight into the molecular mechanisms of spore survival in response to heat treatment and different intervention strategies used to treat fluid skim milk.
Preliminary analysis of cometary dust trails

Dust trails are observed in the orbits of some short-period comets. Large particles, having diameters in the submillimeter range and larger, are ejected by these comets into orbits close to that of the parent comet. By considering the effects of ejection and radiation forces, the spread of particles of different diameters along a parent comet's orbit, both ahead and behind the comet in mean anomaly were modeled. Using this model, the ages of the dust trail material associated with P/Tempel 2, P/Gunn, P/Encke, and P/Schwassmann-Wachmann 1 were estimated; they are found to consist of emissions occurring over a minimum of one to a few orbital periods. It also becomes possible to constrain the particle diameters in a trail segment forward of a comet's orbital position. Such a forward extension is observed in the Tempel 2 and Gunn dust trails, but not the Encke and S-W 1 dust trails. Relative particle sizes among these trails are discussed. The Tempel 2 dust trail is found to have an excess of particles with diameters greater than 1 mm.
An eleven-year cycle in human births.

The prominent endogenous cycle of the sun, with a period of approximately 11 years, is correlated with human conceptions. Time series methods (periodograms and periodic regression analyses) established that an approximate 11-year period exists in the data on births in the 20th century (1909–1985) in the United States and in New Zealand. Statistical comparisons indicated a reliable and direct relationship of conceptions with the approximately 11-year sunspot cycle. These findings were discussed in terms of the possible mediating role of geomagnetic disturbances and other factors that have been suggested in the literature to mediate human conception.
Biotransformation of tamoxifen in a human endometrial explant culture model.

Abstract Although long-term tamoxifen therapy is associated with increased risk of endometrial cancer, little is known about the ability of endometrial tissue to biotransform tamoxifen to potentially reactive intermediates, capable of forming DNA adducts. The present study examined whether explant cultures of human endometrium provide a suitable in vitro model to investigate the tissue-specific biotransformation of tamoxifen. Fresh human endometrial tissue, microscopically uninvolved in disease, was cut into 1×2-mm uniform explants and incubated with media containing either 25 or 100 μM tamoxifen in a 24-well plate. Metabolites were analyzed by reversed-phase HPLC using postcolumn, online, photochemical activation and fluorescence detection. Three metabolites, namely, α-hydroxytamoxifen, 4-hydroxytamoxifen, and N-desmethyltamoxifen were identified in culture medium and tissue lysates. N-desmethyltamoxifen was found to be the major metabolite in both tissue and media extracts of tamoxifen-exposed explants. Incubations of tamoxifen with recombinant human cytochrome P-450s (CYPs) found that CYP2C9 and CYP2D6 produced all three of the above tamoxifen metabolites, while CYP1A1 and CYP3A4 catalyzed the formation of α-hydroxytamoxifen and N-desmethyltamoxifen, and CYP1A2 and CYP1B1 only formed the α-hydroxy metabolite. CYP2D6 exhibited the greatest activity for the formation of all three tamoxifen metabolites. Western immunoblots of microsomes from human endometrium detected the presence of CYPs 2C9, 3A, 1A1 and 1B1 in fresh endometrium, while CYPs 2D6 and 1A2 were not detected. Immunohistochemical (IHC) analysis also confirmed the presence of CYPs 2C9, 3A and 1B1 in fresh human endometrium and in viable tissue cultured for 24 h with or without tamoxifen. Together, the results support the use of explant cultures of human endometrium as a suitable in vitro model to investigate the biotransformation of tamoxifen in this target tissue. In addition, the results support the role of CYPs 2C9, 3A, 1A1 and 1B1 in the biotransformation of tamoxifen, including the formation of the DNA reactive α-hydroxytamoxifen metabolite, in human endometrium.
Pathways to Medical Utilization

The role of psychologists in medical settings is evolving to include the development, delivery, and evaluation of psychosocial treatments for individuals who use disproportionate amounts of medical services. The primary purpose of this article is to present a model of psychological factors that drive health care utilization. A stepped care model of treatment delivery is also discussed along with a brief literature review depicting the impact of treatment approaches on high utilizing populations. This article concludes with recommendations for psychologists interested in providing treatment to medical utilizers.
Extracellular Glutamate Is Increased in Thalamus During Thiamine Deficiency‐Induced Lesions and Is Blocked by MK‐801

The current study measured extracellular fluid (ECF) levels of excitatory amino acids before and during the onset of thiamine deficiency-induced pathologic lesions. Male Sprague-Dawley rats were treated with daily pyrithiamine (0.25 mg/kg i.p.) and a thiamine-deficient diet (PTD). Microdialysates were simultaneously collected from probes inserted acutely via guide cannulae into right paracentral and ventrolateral nuclei of thalamus and left hippocampus of PTD and pair-fed controls. Hourly samples were collected from unanesthetized and freely moving animals. Basal levels obtained at a prelesion stage (day 12 of PTD treatment) were unchanged from levels in pair-fed controls. In samples collected 4-5 h after onset of seizures (day 14 of PTD), the levels of glutamate were elevated an average 640% of basal levels in medial thalamus and 200% in hippocampus. Glutamine levels declined, taurine and glycine were elevated, and aspartate, GABA, and alanine were unchanged during this period. Within 7 h after seizure onset glutamine was undetectable in both areas, whereas glutamate had declined to approximately 200% in thalamus and 70% in hippocampus. No significant change in glutamate, aspartate, or other amino acids was observed in dialysates collected from probes located in undamaged dorsal-lateral regions of thalamus. Number of neurons within ventrolateral nucleus of thalamus was significantly greater in PTD animals in which the probe was dialyzed compared with nondialyzed, suggesting that removal of excitatory amino acids was protective. No significant pathologic damage was evident in hippocampus.(ABSTRACT TRUNCATED AT 250 WORDS)
Glutamyl cysteine synthetase catalytic and regulatory subunits localize to dopaminergic nigral neurons as well as to astrocytes

Glutathione (GSH) is considered one of the primary antioxidant compounds in the brain, important for the removal of peroxides from this organ. GSH levels have been reported to be significantly lower in the substantia nigra (SN) of Parkinson patients vs. age-matched controls. Curiously, GSH has been proposed to be present in brain astrocytes rather than in neurons even though these cells are not lost in Parkinson disease. We report that the catalytic and regulatory subunit proteins of glutamyl cysteine synthetase (GCS), the primary enzyme involved in GSH synthesis, are present not only in astrocytes but also in dopaminergic neurons of the SN. This may have important implications in terms of GSH loss associated with Parkinson disease. J. Neurosci. Res. 64:203–206, 2001. © 2001 Wiley-Liss, Inc.
Manometric characteristics of the upper esophageal sphincter recorded with a microsleeve.

Abstract OBJECTIVES: We compared manometric recordings of the upper esophageal sphincter (UES) recorded with a miniature sleeve to those obtained using standard manometry. METHODS: The UES pressure of eight volunteer subjects was measured by station pull-through (SPT), by rapid pull-through (RPT), and with a microsleeve sensor for 30 min, followed by 15 min of esophageal acid infusion. Deglutitive UES relaxation recorded with a microsleeve and solid state sensor were compared. RESULTS: The UES pressure recorded with the microsleeve (25 ± 9 mm Hg) was significantly less than that by SPT (114 ± 18 mm Hg) or RPT (152 ± 19 mm Hg), and was unaffected by acid infusion. Periods of low UES pressure were observed during long interswallow intervals (11 ± 4, range 6–18 mm Hg). Deglutitive relaxation duration and intrabolus pressure measured with the microsleeve were less than those recorded by the solid state transducer. CONCLUSIONS: “Normal” UES pressure is heavily dependent on measurement technique; pressures obtained with a miniature sleeve are a fraction of those obtained by SPT or RPT. During periods of relative comfort with minimal swallowing, UES tone is approximately 10 mm Hg, similar to that during sleep. Volume modulation of deglutitive UES relaxation is demonstrable with a microsleeve, albeit with less precision than with a solid-state transducer.
Temporal trends in operative obstetric delivery: 1992–1999

Abstract Objective: To evaluate the rates of operative obstetric delivery by indication and gestational age longitudinally from 1992 to 1999. Methods: We reviewed our obstetric database from August 1992 to July 1999, identifying all women undergoing operative obstetric delivery. Incidence, gestational age, and indication for each delivery were recorded and compared temporally over the study interval. Statistical analyses were performed using the χ2 test. Results: Over the study interval, 12,491 deliveries were recorded: 72.0% spontaneous vaginal delivery, 6.8% low/outlet forcep delivery, 0.3% mid-forcep delivery, 2.1% vacuum delivery, and 17.9% cesarean delivery. A significant reduction in the use of forceps was noted from 1992 (10.4%) to 1999 (5.6%) (P Conclusion: The temporal trend of increased cesarean delivery rate appears to be secondary to reduced rate of forceps and vacuum assisted delivery.
Mutagenic conformation of 8-oxo-7,8-dihydro-2'-dGTP in the confines of a DNA polymerase active site.

The crystal structure of human DNA pol beta with DNA template and an incoming 8-oxo-dGTP forming a mutagenic pair with template base A is now presented, revealing the structural constraints within the polymerase active site that result in this mutagenic incorporation.
Effects of a Two-Way Bilingual Program on the Literacy Development of Students in Kindergarten and First Grade.

Abstract This study examines the short-term effects of a two-way bilingual education program on the literacy development of students in kindergarten and first grade. This study compared the literacy development of two groups of children who received different proportions of instruction in English and Spanish. Both the experimental and control groups consisted of students who were English language learners (ELLs), as well as students who were not ELLs (i.e., native English speakers and former ELLs who reached proficiency). Students in the experimental group participated in a two-way bilingual program in which instruction was in English approximately 70% of the time and in Spanish approximately 30% of the time. Students in the control group attended the same school but were in mainstream classes and received instruction in English about 90% of the time. Comparison of test scores (on district-developed assessments and the Scholastic Reading Inventory) of the two groups at the end of the school year indicated...
Extended scene SH wavefront sensor algorithm: Minimization of scene content dependent shift estimation errors

Adaptive Periodic-Correlation (APC) algorithm was developed for use in extended-scene Shack-Hartmann wavefront sensors. It provides high-accuracy even when the sub-images in a frame captured by a Shack-Hartmann camera are not only shifted but also distorted relative to each other. Recently we found that the shift-estimate error of the APC algorithm has a component that depends on the content of extended-scene. In this paper we assess the amount of that error and propose a method to minimize it.
Time and space resolved neutron diagnostic systems for magnetically confined plasmas

Abstract Neutron spectrometer/counter systems have been developed for diagnostic measurements on magnetically confined deuterium and deuterium-tritium plasmas. An early version was used to determine the mean ion energy as well as the ion-energy confinement time in the endplugs of the Tandem Mirror Experiment. A recent upgrade includes a 10 MHz pulse height analysis and particle identification capability for time- and space-resolved neutron spectrum measurements. Resolution is adequate for a neutron Doppler-width measurement of mean ion energy in near-future confinement experiments such as the Mirror Fusion Test Facility.
Complement dances with T cells.

Conventionally, complement is considered mostly a component of innate immune system; however, emerging data suggest that complement has pleiotropic effects impacting many aspects of the immune system. The modulation of T-cell responses and shaping of the overall immune response by locally produced/
Managing heart failure: a critical appraisal of the literature.

Background Preventing heart failure (HF) rehospitalizations requires examination of evidence-based research, which may lead to opportunities to improve on care transitions upon discharge from an acute care setting. This review was conducted to identify current literature in HF and disease management without focusing specifically on disease management programs. Purpose The purpose of this study was to conduct a systematic review of the literature to better understand how to structure interventions for HF patients upon transition from the hospital to home and to outline critical research gaps. Conclusion Patients recently hospitalized for HF or at high risk for HF decompensation should be considered for comprehensive heart failure disease management (HFDM) and/or structured HF interventions. Level 1 evidence demonstrated positive benefits from HFDM programs, structured telephone support, and telemonitoring interventions as an effective component of contemporary multidisciplinary HF management. Clinical implications Based on the evidence from this critique, key features and recommendations are provided. Also discussed is the State Action on Avoidable Rehospitalizations program, which may provide acute care centers in Massachusetts an opportunity to create an ideal transition home for HF patients.
Bipolar Pre-Planetary Nebulae: Hydrodynamics of Dusty Winds in Binary Systems. II. Morphology of the Circumstellar Envelopes

We have constructed three-dimensional smoothed particle hydrodynamics models to examine the influence of a detached binary companion on the dusty winds from red giants and asymptotic giant branch (AGB) stars and the degree to which this model can reproduce some of the observable characteristics of axisymmetric or bipolar pre-planetary nebulae. In this second paper in the series, we focus our attention on the morphology of the circumstellar envelopes. The parameter space of our models includes wind outflow velocities in the range 10-26 km s-1, circular orbits with binary separations 3.6-50 AU, and binary companions having masses in the range 0.25-2 M☉. By varying these parameters, we find a continuous range of envelope geometries and density contrasts that correspond well to observational classifications of planetary and pre-planetary nebulae: bipolar, with density contrasts from 10 to >200 between the equatorial plane and the polar direction; elliptical, with intermediate contrasts of 5-10; and quasi-spherical, with very low density contrasts. This last category manifests a hitherto unknown type of hydrodynamic solution, in which a spiral shock is formed, covering most of the solid angle around the binary. The cross sections of these shocks, and to a lesser extent the two-dimensional projections of the quasi-spherical envelopes, appear as a series of rings in the wind. We discuss the observational implications of that type of wind solution. The quasi-spherical geometry is the prevailing type in parameter space. From binary statistics we estimate that ~34%-40% of detached binaries will give rise to bipolars for a 10 km s-1 outflow. We present a classification scheme of the envelope geometries based on a combination of binary and wind parameters. We also find that the mass accretion rates onto the secondary are systematically lower than is predicted by the Bondi-Hoyle theory.
High prevalence of postpartum anemia among low-income women in the United States ☆

Abstract Objective: To determine the prevalence of anemia from 4 to 26 weeks post partum and to examine prenatal predictors of postpartum anemia. Study Design: Retrospective cohort analysis of 59,428 participants in the Special Supplemental Nutrition Program for Women, Infants, and Children in 12 US states. Results: The prevalence of postpartum anemia was 27%. Anemia rates were higher among minority women, reaching 48% among non-Hispanic black women. Of 9129 women who had normal hemoglobin in the third trimester, 21% had postpartum anemia. Prenatal anemia was the strongest predictor of postpartum anemia (adjusted odds ratio, 2.7; 95% confidence interval, 2.5-2.8). Maternal obesity, multiple birth, and not breast-feeding also predicted postpartum anemia. Conclusion: The high prevalence of post partum anemia among low-income women highlights the importance of anemia screening at 4 to 6 weeks post partum. These data suggest that screening should not be limited, as it is at present, to women considered at high risk. (Am J Obstet Gynecol 2001;185:438-43.)
The Temporal Expression of Transforming Growth Factor-β1in Early Aortocoronary Vein Grafts

The success of coronary reconstructive procedures is limited by the high incidence of restenosis secondary to intimal hyperplasia (IH). Transforming growth factor-β 1 (TGF-β 1 ) is a growth factor which has been shown to be important in the early development of IH in arteries and peripheral vein grafts. To date, there is little information concerning the early remodeling in aortocoronary vein grafts (ACVG). The purpose of this study was to characterize the expression of TGF-β1 expression in early aortocoronary vein grafts. Eighteen mongrel dogs underwent aortocoronary vein bypass grafting. Vein grafts were excised at 2 hr, 4 hr, and 7 days after implantation, snap frozen, and processed for ribonuclease protection assays (RPA) using 32 P-labeled riboprobes for TGF-β 1 and 18 S rRNA. TGF-β1 expression was quantified by densitometric analysis of autoradiographs which were expressed as a ratio TGF-β 1 /rRNA. Representative vessel rings were also collected for histology. There was a significant rise in TGF-β 1 expression in the 2-hr vein grafts (0.42 ± 0.04 compared to control saphenous vein 0.21 ± 0.05, P < 0.02). In addition, there was significant downregulation of TGF-β 1 at 4 hr (0.28 ± 0.05) and at 7 days (0.18 ± 0.01) when compared to 2 hr (P < 0.05). Histological specimens showed minimal intimal hyperplasia at 7 days. These results show for the first time an acute rise in TGF-β 1 expression in ACVG. This upregulation quickly subsides by 4 hr and gene expression approaches control values by 7 days. By understanding this temporal relationship of expression one could better target potential therapeutic modalities to attenuate IH.
Potential induced changes in the electronic states of monolayer guanine on graphite in NaCl solution

Abstract Monolayer guanine on graphite has been studied in NaCl solution by scanning tunneling microscopy (STM) and atomic force microscopy (AFM) as a function of the substrate potential. The STM image of the monolayer changes dramatically as the potential varies, while the AFM image shows no changes over a broad potential range. The observation indicates that the electronic states of organic films can be modified and controlled at solid-liquid interfaces, and STM can provide a local measurement of potential dependent electronic states.
Alterations in regional brain GABA concentration and turnover during pregnancy

Abstract During pregnancy, mice are more susceptible to flurothyl-induced seizures than are nonpregnant control mice. The potential role of brain GABA in mediating this behavior was examined in the present study. GABA concentrations in the cerebellum, hippocampus, striatum, midbrain, and cortex from individual control, pregnant (days 17–18) and delivery-day Heterogeneous Stock mice were assayed using a fluorometric method. Turnover of GABA was assessed by inhibiting metabolism with aminooxyacetic acid and measuring GABA accumulation over the next 2 h. Steady-state GABA concentrations decreased significantly from control in all brain regions during pregnancy. Reductions in GABA concentrations were approximately 25–30% in the affected regions. At parturition, GABA concentrations in the cerebellum and cortex returned to control levels, but hippocampal, striatal, and midbrain GABA levels remained significantly depressed. All the indices of GABA turnover-first-order rate constant, half-life, initial rate of synthesis, and turnover rate (product of first-order rate constant and initial concentration)-showed a significant reduction in pregnancy, which was continued through the time of delivery in all brain regions except the hippocampus. Half-life values for GABA increased nearly fourfold in the cerebellum and cortex. These results show that there is a significant alteration in GABAergic systems during pregnancy and parturition. We suggest that the reduction in GABA turnover is a compensatory anticonvulsant mechanism to offset the inherent seizure susceptibility brought about by the reduced level of the major inhibitory neurotransmitter in the brain.
Memory: an overview, with emphasis on developmental, interpersonal, and neurobiological aspects.

ABSTRACT Objective To review recent findings from memory research and related scientific studies and to provide an overview of their implications for clinical practice. Method Published research data from a range of scientific disciplines are summarized and integrated into a conceptual framework regarding the interpersonal, neurobiological, and subjective nature of the development of memory. Results Memory is a fundamental property of the human mind that has been the focus of research of a wide range of academic disciplines. Convergent findings from these various studies suggest that the fundamental elements of memory can be best understood by focusing on its origins in the brain and the impact of social communication on its development. Conclusions An interdisciplinary approach is important for the clinician who seeks to understand the various layers of memory that develop during the early years of life.
Probing the Strand Orientation and Registry Alignment in the Propagation of Amyloid Fibrils

Detailed knowledge of the structure and growth mechanism of amyloid fibrils is important for understanding the disease process. Recently, solid-state NMR and other spectroscopic data have revealed the equilibrium organization of the tertiary structure of fibrils formed by various segments of β-amyloid peptides. A three-step “dock-and-lock” mechanism for fibril growth has been proposed on the basis of the kinetic data. Here we use all-atom replica-exchange molecular dynamics simulations in generalized-Born implicit solvent to probe the mechanism of tertiary structure propagation in fibrils of Aβ16−22 modeled as an oligomer consisting of two β-sheets each having four strands. The data show that following association with the oligomer, but before being fully locked onto the existing β-sheet, the added monomer predominantly samples states with the antiparallel strand orientation, but both in- and one-residue shifted backbone hydrogen bond alignments. The in-register state, which is the experimentally observed...
Dispersion of heavy particles by turbulent motion

Abstract Accurate prediction of heavy particle dispersion in turbulent flows requires a simultaneous consideration of particle's inertia and particle's drift velocity. A mathematically simple and physically comprehensive analysis was developed to solve the dispersion statistics of heavy particles in a homogeneous and isotropic turbulent flow. Normalized particle diffusivity, rms fluctuating velocity, and Lagrangian integral time were related by algebraic equations to three dimensionless parameters: the inertia parameter, the drift parameter, and the turbulence structure parameter. When the drift parameter is large, dispersion scales are very sensitive to the inertia parameter. Heavy particles were found to disperse faster than fluid elements if the inertia parameter controls the dispersion and slower than fluid elements if the drift parameter governs the dispersion. This finding explains previous “contradictory” dispersion data observed in experimental measurements. Not only the particle time respective b...
Distribution of Nonciliated Bronchiolar Epithelial (Clara) Cells in Intra- and Extrapulmonary Airways of the Rabbit

Three types of nonciliated secretory epithelial cells are thought to contribute to the mucous lining of intrapulmonary airways: mucous cells, serous cells, and Clara cells. The Clara cell is distinguished from the other two by low cuboidal shape, presence of membrane-bound electron-dense ovoid secretory granuLes, abundant apical agranular endoplasmic reticulum (AER), and its location as the lining cell of distal conducting airways (bronchioles). The present study was designed to define the distribution of the Clara cell within the trachea and intrapulmonary airway tree. We correlated airway size, generation of branching, and airway wall components with Clara cell morphology and abundance. Lungs of 6 male rabbits (8-15 weeks old) free of respiratory disease were fixed by airway infusion of glutaraldehyde/paraformaldehyde at 30 cm pressure. The trachea, primary bronchi, and airways of the right cranial lobe of each lung were exposed by microdissection. The branching pattern was recorded and numbered. One half of the dissected lung was processed for scanning electron microscopy and the other half embedded as large epoxy blocks for simultaneous transmission electron and light microscopy. The percentages of ciliated, mucous, nonciliated, and basal epithelial cells were quantitated by light microscopy. Basal cells and peribronchial cartilage were absent distal to the fourth intrapulmonary generation in both the axial airway and its first major branch. Mucous (goblet) cells were present (less than 2%) only in trachea and primary and lobar bronchi. Nonciliated cells were more abundant distally, constituting 21%-45% of the epithelium in cartilaginous airways and 35%-65% in noncartilaginous ones. In the first six airway generations including trachea, nonciliated cells were without large apical protrusions but were covered by long microvilli. Cells of more distal airways had prominent apical protrusions and lacked microvilli. Nonciliated cells in all airways had abundant apical AER, granular endoplasmic reticulum (GER), and electron-dense ovoid granules. Cells in proximal airways were columnar rather than low cuboidal and had more GER. Only nonciliated cell shape, luminal surface, and granule abundance varied with airway size and generation. We concluded that the nonciliated secretory cell lining all intrapulmonary airways in the rabbit lung is one cell type, the Clara cell.
C-terminal Mutations That Alter the Turnover Number for 3-O-Methylglucose Transport by GLUT1 and GLUT4

Turnover numbers for 3-O-methylglucose transport by the homologous glucose transporters GLUT1 and GLUT4 were compared to those for truncated and chimeric transporters expressed in Xenopus oocytes to assess potential regulatory properties of the C-terminal domain. The ability of high intracellular sugar concentrations to increase the turnover number for sugar entry ("accelerated exchange") by GLUT1 and not by GLUT4 was maintained in oocytes. Replacing the GLUT1 C terminus with that of GLUT4 stimulated turnover 1.6-fold, but abolished accelerated exchange. Thus, the GLUT1 C terminus permits accelerated exchange by GLUT1, but in doing so must interact with other GLUT1 specific sequences since the GLUT4ctrm1 chimera did not exhibit this kinetic property. Removal of 38 C-terminal amino acids from GLUT4 reduced its turnover number by 40%, whereas removing only 20 residues or replacing its C terminus with that of GLUT1 increased its turnover number 3.5-3.9 fold. Therefore, using mechanisms independent of those which alter transporter targeting to the plasma membrane, C-terminal mutations in either GLUT1 or GLUT4 can activate transport normally restricted by the native C-terminal domain. These results implicate the C termini as targets of physiological factors, which through covalent modification or direct binding might alter C-terminal interactions to regulate intrinsic GLUT1 and GLUT4 transporter activity.
Comparison of classifier performance estimators: a simulation study

We aim to compare resampling-based estimators of the area under the ROC curve (AUC) of a classifier with a Monte Carlo simulation study. The comparison is in terms of bias, variance, and mean square error. We also examine the corresponding variance estimators of these AUC estimators. We compared three AUC estimators: the hold-out (HO) estimator, the leave-one-out cross validation (LOOCV) estimator, and the leave-pair-out bootstrap (LPOB) estimator. Each performance estimator has its own variability estimator. In our simulations, in terms of the mean square error, HO is always the worst and the ranking of the other two estimators depends on the interplay of sample size, dimensionality, and the population separability. In terms of estimator variability, the LPOB is the least variable estimator and the HO is the most variable estimator. The results also show that the estimation of the variance of LPOB using the influence function approach with a finite data set is unbiased or conservatively biased whereas the estimation of the variance of the LOOCV or the HO is downwardly (i.e., anti-conservatively) biased.
Intrinsic modulation of lymphocyte function by stromal cell network: advance in therapeutic targeting of cancer.

Advances in tumor biology have demonstrated a point of critical importance: tumor are established as an intersection of malignant clone cells and surrounding stromal cells. The stroma is composed of nonhematopoietic cells, including connective tissue cells, blood vessels, nerves, fat and smooth muscle cells, in the extracellular matrix niche. Recent studies have demonstrated that stromal cells regulate immune responses by: coordinating lymphocyte homing, differentiation, activation and antigen responses; inducing tolerance; and maintaining immunologic memory. Hence, elucidation of the interaction between stromal cells and lymphocytes is essential for generating effective immunotherapies. In this article, we summarize what is currently known about the interactions between stromal cells and lymphocytes in the tumor microenvironment, as well as potential immunotherapeutic approaches targeting stroma–lymphocyte interactions; both in the context of our work on multiple myeloma, and of recent literature in both...
A mapping algorithm for domain decomposition in massively parallel finite element analysis

Abstract A new mapping algorithm is presented for domain decomposition for the purpose of allowing researchers to conduct finite element analysis on massively parallel computers. Over the last few years, massively parallel MIMD machines such as the Intel Touchstone Delta and recently the Intel Touchstone Paragon have become increasingly popular for speeding up finite element computations. Most of these applications use domain decomposition as a first step towards conquering the problem. Many different algorithms have been developed by researchers to achieve an effective domain decomposition. Some of these methods use connectivity information only, some use coordinate information only, while others use both of them together. Some algorithms are based on assigning weights to nodes using a particular strategy while others are recursive in nature. As will be discussed in this paper, the logic employed in various algorithms works perfectly well for certain meshes to be decomposed, in certain numbers of subdomains; while it gives far from perfect results for other meshes or for same meshes to be decomposed in a different number of subdomains. The logic used in the proposed algorithm has been developed in a creative way such that it is closer to a human's natural thinking when making decisions. Fairly large meshes can be decomposed in a matter of seconds on a Sun Sparc station by the proposed algorithm. Its execution time remains almost the same for any number of subdomains.
Slowed glycogen utilization enhances exercise endurance in patients with heart failure

Abstract OBJECTIVES The objective of the study was to investigate the impact of alteration of glycogen stores and metabolism on exercise performance in patients with heart failure. BACKGROUND In normal subjects, muscle glycogen depletion results in increased exertional fatigue and reduced endurance. Skeletal muscle biopsies have revealed reduced glycogen content in patients with congestive heart failure (CHF). Whether glycogen depletion contributes to reduced endurance and abnormal ventilation in these patients is unknown. METHODS Bicycle exercise tests with measurement of respiratory gases were performed following dietary manipulations to induce glycogen depletion (60% protein, 40% fat) and slow glycogen utilization (60% carbohydrate, 30% fat, 10% protein) in 13 patients with CHF (left ventricular ejection fraction 22 ± 6%; age 48 ± 9 years) and 7 control subjects (age 45 ± 5 years). Maximal exercise, exercise at 75% of peak workload until exhaustion and 1-min cycles of supramaximal exercise at 133% of peak were performed on three occasions over a two-week period. RESULTS Significant changes in resting respiratory quotients (RQs) in normal (Baseline: 0.78 ± 0.03; Depleted: 0.69 ± 0.05) and CHF subjects (Baseline: 0.84 ± 0.05; Depleted: 0.72 ± 0.05) were observed (both p CONCLUSIONS Glycogen depletion minimally affects maximal exercise performance, endurance or ventilation in CHF patients, whereas slowed glycogen utilization markedly enhances exercise endurance. Therapeutic interventions that increase or slow use of glycogen stores may have clinical benefit.
The effect of hypothermic ischemia on the α‐adrenergic mechanisms of the canine tibia vascular bed

The effect of hypothermic ischemia on alpha-1 and -2 adrenergic receptor mediated vasoconstriction has been studied in an in vitro perfused canine tibia preparation. Bones were perfused at a constant rate with aerated (95% O2, 5% CO2) modified Krebs Ringer solution and the effect of bolus injections of norepinephrine (0.025-6.4 nmol) on the perfusion pressure was studied. For all bones the first dose-response curve was produced under control conditions. In one group the second dose-response curve was generated during a constant infusion of prazosin (alpha-1 adrenergic antagonist); in another it was produced during a constant infusion of rauwolscine (alpha-2 adrenergic antagonist); in the control group it was generated under control conditions. The results demonstrate that, after 48 h of hypothermic ischemia, alpha-1 adrenergic-mediated vasoconstriction was significantly attenuated (p less than 0.001). However, alpha-2 adrenergic-mediated vasoconstriction was unaffected by increasing periods of hypothermic ischemia.
Relation between mortality of young walleye (Stizostedion vitreum) and recruitment with different forms of compensation

The relation between mortality of young fish and recruitment is important for assessment of the environmental effects of facilities that kill large numbers of young fish, such as electric power stations and hydropower plants. A simulation model with a bioenergetic growth component was applied to examine the relation between mortality of young and recruitment for walleye (Stizostedion vitreum) with different forms of population regulation, including: food limited growth, food limited growth with size-dependent mortality, and food limited growth with age at maturity dependent on size. With food limited growth small increases in mortality of young reduced recruitment considerably, but the population slowly approached a new equilibrium. If mortality of young increased when growth was food limited, the population approached a new equilibrium of natality and mortality because with fewer individuals there was more food per individual, and individuals were larger in size and produced more eggs; this feedback adjusted natality to equal mortality. With either mortality or age at maturity dependent on size, large increases in mortality of young resulted in only small decreases in recruitment.