cssi/SciSciGPT-SciSciNet huggingface dataset:
Components of the mixed-function oxidase of hepatic microsomes of fresh water fishes

Abstract 1. 1. Varlations in hepatic mixed-function oxidase (MFO) ability to epoxidize and hydroxylate cyclodiene insecticides are observed among various freshwater fish. 2. 2. The rate of aldrin epoxidation in fish varies from 0·44 to 2·45 n-mole dieldrin formed/min/per mg protein as compared with 3·35 n-mole dieldrin formed/min/per mg protein in male mouse. 3. 3. The rate of metabolism of chlordene to its three products (1-hydroxychlordene, 2,3-epoxychlordene, and 1-hydroxy-2,3-epoxychlordene) varies from 0·59 to 2·15 in fishes as compared with 5·0 n-mole products/min/mg protein in male mouse. 4. 4. The ability of MFO to epoxidize aldrin appears to correlate with the concentration of P-450 and the activity of NADPH-cytochrome- c -reductase in the fish, Trout, Bluegill, and Kissing Gourami as well as in the mouse. 5. 5. The concentration of P-450 varies from 0·56 to 1·03 n-moles/mg protein in these three fish and can be lowered in the Trout, by starvation, from 0·56 to 1·19 n-moles P-450/mg protein. 6. 6. The P-450 of the fish, like that of the mouse, binds aliphatic chlorinated cyclodienes and hexobarbital as type I and aniline as type II substrates.
Quantitative Spatiotemporal Analysis of Antibody Fragment Diffusion and Endocytic Consumption in Tumor Spheroids

Antibody-based cancer treatment depends upon distribution of the targeting macromolecule throughout tumor tissue, and spatial heterogeneity could significantly limit efficacy in many cases. Antibody distribution in tumor tissue is a function of drug dosage, antigen concentration, binding affinity, antigen internalization, drug extravasation from blood vessels, diffusion in the tumor extracellular matrix, and systemic clearance rates. We have isolated the effects of a subset of these variables by live-cell microscopic imaging of single-chain antibody fragments against carcinoembryonic antigen in LS174T tumor spheroids. The measured rates of scFv penetration and retention were compared with theoretical predictions based on simple scaling criteria. The theory predicts that antibody dose must be large enough to drive a sufficient diffusive flux of antibody to overcome cellular internalization, and exposure time must be long enough to allow penetration to the spheroid center. The experimental results in spheroids are quantitatively consistent with these predictions. Therefore, simple scaling criteria can be applied to accurately predict antibody and antibody fragment penetration distance in tumor tissue.
Jacobi forms of higher index and paramodular groups in \mathcal{N} = 2, D = 4 compactifications of string theory

We associate a Jacobi form over a rank s lattice to $ \mathcal{N} $ = 2, D = 4 heterotic string compactifications which have s Wilson lines at a generic point in the vector multiplet moduli space. Jacobi forms of index m = 1 and m = 2 have appeared earlier in the context of threshold corrections to heterotic string couplings. We emphasize that higher index Jacobi forms as well as Jacobi forms of several variables over more generic even lattices also appear and construct models in which they arise. In particular, we construct an orbifold model which can be connected to models that give index m = 3, 4 or 5 Jacobi forms through the Higgsing process. Constraints from being a Jacobi form are then employed to get threshold corrections using only partial information on the spectrum. We apply this procedure for index m = 3, 4 or 5 Jacobi form examples and also for Jacobi forms over A 2 and A 3 root lattices. Examples with a single Wilson line are examined in detail and we display the relation of Siegel forms over a paramodular group Γ m to these models, where Γ m is associated with the T-duality group of the models we study. Finally, results on the heterotic string side are used to clarify the linear mapping of vector multiplet moduli to Type IIA duals without using the one-loop cubic part of the prepotential on the Type II side, and also to give predictions for the geometry of the dual Calabi-Yau manifolds.
Pregnancy Maintenance with Corticosterone in Protein-Depleted Rats: A Study on Fetal Protein Composition

A pregnancy maintenance of only 8% was obtained when rats were fed a protein free diet throughout gestation. Administration of 5 mg corticosterone on each of days S to 9 improved pregnancy maintenance to 62%. In comparison with fully fed rats, fetal weight and fetal protein (concentration and total) were significantly less in the corticosterone maintained protein deprived animal. However, fetal hepatic protein, RNA and DNA concentrations compared favorably with those of the full fed animal; total content of each of these constituents was subnormal in protein deficiency. Thus total cell numbers were fewer but cell size (P/DNA) was normal. Corticosterone may serve to mobilize amino acids and to release prolactin as a potential mode of action. (Endocrinology 90: 318, 1972)
A comparison of NASA, DoD, and hydrocode ballistic limit predictions for spherical and non-spherical shapes versus dual- and single-wall targets, and their effects on orbital debris penetration risk

Abstract All earth-orbiting spacecraft are susceptible to impacts by these particles, which can occur at extremely high speeds and can damage flight- and mission-critical systems. The traditional damage mitigating shield design for this threat consists of a “bumper” that is placed several cm away from the main “inner wall” of the spacecraft. Typical orbital debris risk analyses that include ballistic limit equations (BLEs) and curves (BLCs) assume that orbital debris particles are spherical in shape. However, spheres are not a common shape for orbital debris; rather, debris fragments might be better represented by other regular or irregular solids. This paper presents the results of a study comparing BLCs developed by NASA and the DoD for velocities up to 4 km/s considering spheres, cubes, and a “flake” shape that was proposed within NASA's Standard Breakup Model to represent orbital debris. It also compares performance of these shapes using hydrocodes at higher velocities (7–12 km/s), and generates a combined BLC for these shapes for the entire orbital debris velocity regime. In addition to shape, a multi-view method is used to examine the effects of a variety of cube and flake impact orientations on BLC, as well as a “characteristic length” parameter developed by NASA to compare the particle shapes on the basis of their radar cross section. The developed non-spherical BLCs are then evaluated for overall penetration risk considering the orbital debris environment. Their predictions of risk are compared to that predicted using sphere-based BLCs. This methodology is then extended to a single-wall shield design for velocities up to 15 km/sec, and the results of DoD predictions for a sphere and cube are compared with NASA predictions for a sphere having the same characteristic length. The results indicate that we may be over-predicting orbital debris risk for dual-wall shields by a factor of two—and for single walls by a factor of four—by limiting our analyses to spheres instead of using more representative debris shapes, such as cubes and flakes, and its characteristic length as the primary particle parameter.
The effect of chronic applications of tretinoin(retinoic acid) on acute responses of mammalian skin to UVB radiation in vivo.

The effects of long—term applications of tretinoin(retinoic acid; RA) on acute responses to UVB radiation were examined in hairless mouse skin in vivo. The skin was examined histologically and the radioactive tracer [3H]-thymidine was used to study premitotic semiconservative DNA synthesis in the epidermal basal cells. Ten and 23 wk applications of a 0.05% RA solution (3 times a wk) induced epidermal acanthosis, hypertrophy of the individual cells and an increased number of [3H]-thymidine-labelled basal cells. At both time periods there was a distinct reduction in the expected inhibition of DNA synthesis at 4 h and the expected acceleration of DNA synthesis at 48 h after a single exposure to UVB radiation. In addition, the histologic morphology was unchanged at 48 h post irradiation. Thus, the repeated RA applications had a definitive influence on at least two aspects of the cutaneous response to UVB energy.
Laser Coating of HAp/Ti Nanoparticles on Metal Implants: Interfacial Bonding Strength, Chemical Analysis and Biocompatibility

In this paper, laser coating of hydroxyapatite (HAp) and Ti nanoparticles on Ti-6Al-4V implants was developed. An Nd:YAG laser was used to coat multilayers of HAp and Ti nanoparticles on implants. This coating process has the following advantages: (1) low temperature coating of nanoscale HAp is realized due to good sinterability of titanium nanoparticles; (2) high interfacial strength between layer and substrate because of the functional multilayer coating; (3) HAp nanoparticles provide better biocompability than micro-particles; (4) biphasic calcium phosphate (BCP) could be introduced, which has been reported to have excellent biocompatibility. In order to achieve these goals, careful selection of laser processing parameters is required. A multiphysics model is built and validated with experiments. This model is employed to determine the appropriate laser processing conditions. After laser processing, the features of the coated samples were characterized, including microstructures, chemical compositions, surface roughness, structure porosity and interfacial bonding strength. Qualitative cell culture studies with osteoblast-like UMR-105 cells were carried out to reveal the biocompatibility of so-coated implants. It is found that multilayer laser coated nanoHAp/Ti implants has beneficial biocompatibility, surface roughness, maintained chemical composition, porous microstructure and strong coating/substrate interfacial strength.Copyright © 2010 by ASME
Erosion of Silicon Single Crystals

The erosion of Si single crystals by angular Al2O3 particles was investigated over a range of particle diametersD (23 to 270 μm), velocities v (32 to 134 m/s), and impact angles α (22° to 90°). For α≥45°, the steady-state erosion rate can be described within the framework of existing models by the modified relation ΔW∞(v sin α-v0)2.6(D-D0)0.6. The results are consistent with the relation D0v=Dv02200 × 10−6 m2/s for the threshold values D0 and v0. For α=22°, another term must be added, and could represent a contribution of plasticity. The results also indicate that surface morphology and/or subsurface-damage structures are important.
STRATEGIES OF CHILDREN DURING PERFORMANCE OF A SELF-PACED ACTIVITY

Summary.-This study asked whether children, when performing self-paced work, would stop to rest rather than slow the work rate, as has been demonstrated in adults. G boys were tested individually for four testing periods during a selfpaced bicycle ergometer ride. Eight characteristics of self-paced activity were computed and analyzed for each testing period. The characteristics were analyzed in a trials-subjects design to determine the stability of their strategies for accomplishing a fixed quality of work. It was determined that the total ride time and rate were held relatively constant with an increase or decrease in the number of stops and/or the total stopping rime. By design, a self-paced mode of working on a bicycle ergometer allows S to vary his pace and his work-to-rest ratio. The external workload is standardized and held constant by maintaining a predetermined resistance and number of revolutions of the bicycle pedals (Ellis & Hubbard, 1973). When the pedalling rate is not controlled by the investigator the internal physiological work (energy expenditure) and power output varies within and between Ss. The freedom to vary the pedalling allows each S the opportunity to regulate his internal work and power output levels and to determine the ultimate strategy for the ergometer ride. Gerben and House (1969) used self-paced activity as the working mode for a study determining the characteristics of self-paced activity and the effects of hypoxia on behavior of adults. Their findings indicated variations in activity levels and that a common strategy was used by Ss during the bicycle ergometer ride. Ss paced themselves by stopping rather than changing their pedalling rate. In another study Gerben, House, and Winsmann (1972) investigated the effects of pedal resistance, motivational contingency, and inspired oxygen concentration upon a self-paced ergometer performance. They showed fluctuations in activity level during the performance of the bicycle ergometer ride similar to those defined by Gerben and House (1969) but did not identify Ss' strategies. Varying activity levels have been observed in children at play. Mean activity levels were modulated by increasing or decreasing the complexity of the stimulus environment. As the stimulus environment became more complex, by increasing the number of children in a group or the quantity of apparatus, the children's activity level also rose (Wade & Ellis, 1971). Activity has also been shown to fluctuate regularly for a given setting. The children seem to
Converter Domain Residue R759 Interaction with Relay Loop Residue N509 in Drosophila Muscle Myosin is Critical for Motor Function, Myofibril Stability and Flight Ability

We used an integrative approach to probe the significance of the interaction between the relay loop and converter domain of Drosophila melanogaster skeletal muscle myosin. We generated a transgenic line expressing myosin with a mutation in the converter domain (R759E) at the relay loop interaction site. The mutation depresses calcium, basal or actin-activated MgATPase values (Vmax) by ∼60% and actin sliding velocity ∼35% compared to wild-type myosin. Ultrastructure of two-day-old adult fibers shows cracking and frayed myofibrils with some disruption of the myofilament lattice which becomes more severe in one-week-old adults. Flight ability is reduced in two-day-old flies compared to controls and is absent in 1-week-old adults. Thus appropriate interaction between the relay loop and converter domain is essential for normal motor function, myofibril stability and locomotion. To examine the specificity of this interaction, we used a compensatory mutational approach to attempt to restore the function of the R759E mutant myosin. Our modeling indicates that relay loop residues N509 and D511 interact with converter domain residue R759. To verify our model, we generated two transgenic lines that express R759E and either the N509K or D511K mutations. Interestingly, calcium, basal, and actin stimulated ATPase values are restored to 70% and actin sliding velocity is restored to 90% in N509K/R759E but not in D511K/R759E. Structurally fibers from 2-day or one-week -old adults appear morphologically normal in N509K/R759E and their flight ability is like wild type. However, D511K/R759E myofibrils do not show any improvement compared to R759E and flight ability is worse than R759E. Overall, our results reveal the critical interaction between the converter domain with relay loop residues and their role in myosin motor function and myofibril assembly/stability.
Benzodiazepine binding after in vivo elevation of GABA.

Abstract [3H]Diazepam binding was measured in rat cortical membranes. Acute and chronic amino-oxyacetic acid (AOAA) pretreatment greatly increased GABA levels, but did not alter diazepam binding. The GABA normally present was sufficient/to maximally stimulate diazepam binding. In in vivo binding studies, acute and chronic AOAA treatment increased the amount of [3H]diazepam in the brain at the time of sacrifice, thus increasing both specific and nonspecific binding and leaving unchanged the fraction of drug specifically bound. Fluctuation of brain GABA may not affect benzodiazepine binding unless the normal concentration is greatly depressed.
Non-random interaction of N-2-acetylaminofluorene and its N-hydroxy metabolite with DNA of rat hepatic parenchymal and non-parenchymal cell nuclei following in vivo administration of carcinogen

Abstract Treatment of rats with the hepatocarcinogen, N-2-acetylaminofluorene (AAF) results in development of malignant tumors derived primarily from hepatic parenchymal cells. Following administration of AAF, or its N-hydroxy derivative, in vivo nuclei from parenchymal cell and non-parenchymal cell populations (NI and NII nuclei populations, respectively) were isolated and treated with the endonuclease DNase I. The binding of carcinogen residues to the DNA of nuclease-accessible vs. nuclease-resistant regions of chromatin was evaluated on the basis of the selectivity of DNase I for transcriptionally active DNA. Under the experimental conditions employed DNase I digested approx. 50–60% of the genome of NI nuclei while only 10–20% of the DNA from non-parenchymal cell nuclei (NII) was susceptible to this enzyme. When the DNA of NI and NII nuclei were nick translated following limited digestion with DNase I, a greater degree of transcriptional activity (nuclease accessibility) was found in parenchymal cell nuclei (NI). Following a single injection of rats with [ring-3H]AAF or its N-hydroxy metabolite (N-[ring-3H]-OH-AAF) (1.8 μmol carcinogen/100 g), adducts were preferentially associated with DNA of DNase I resistant regions of target cell nuclei (NI), while preferentially associated with nuclease-accessible regions of non-target cell nuclei (NII). Damage following a single injection persisted for up to 3 days in DNase I-resistant DNA of NI nuclei, carcinogen adducts were rapidly lost from DNase I-accessible DNA of NII nuclei. These studies stress the importance of investigating specificity of carcinogens for particular regions of the genome of cell subpopulations within the target organ.
Generation of reactive oxygen species from the reaction of selenium compounds with thiols and mammary tumor cells.

Abstract Sodium selenite, sodium selenate, selenocystine and selenomethionine were tested for their abilities to generate Superoxide by the oxidation of glutathione and other thiols in the absence and presence of cells of the human mammary tumor cell line HTB123/DU4475. Free radical generation was measured by lucigenin- or luminol-amplified chemiluminescence. In the absence of tumor cells, lucigenin-dependent chemiluminescence was observed from the reaction of selenite with the thiols glutathione, 2-mercaptoethanol and l -cysteine, but not with oxidized glutathione. Superoxide dismutase, catalase, and glutathione peroxidase all suppressed the observed chemiluminescence; but when these enzymes were heat inactivated they had little suppressive inhibition on chemiluminescence. Luminoldependent chemiluminescence from the reaction of selenite with glutathione was much less than that observed by lucigenin-amplified chemiluminescence. In the presence of the HTB123/DU4475 mammary tumor cells, lucigenin-dependent chemiluminescence was observed from the reactions of selenite and selenocystine with glutathione which were 5 and 23 times greater than their respective reactions with glutathione in the absence of tumor cells. The enhanced chemiluminescence generated by selenite and selenocystine in the presence of the tumor cells was also suppressed by Superoxide dismutase, catalase and glutathione peroxidase. These data suggest that a free radical, the Superoxide anion (O 2 − , and H 2 O 2 ; are produced from the reaction of selenite and selenocystine with glutathione. These free radical reactions may account for the toxicity of selenite and selenocystine in vitro in comparison to a near absence of acute tumor cell toxicity and Superoxide generation by selenate and selenomethionine with thiols. Enhanced chemiluminescence in the presence of tumor cells may be an expression of cellular selenium metabolism and the capability of cells to form selenium metabolites that more easily oxidize glutathione and other thiols producing reactive free radicals and peroxides.
Subtyping of substance use disorders in a high-risk welfare-to-work sample: A latent class analysis

The goals of this study were (a) to investigate the existence of substance abuse/dependence subtypes in a diverse low-income welfare to work sample and (b) to explore subtype differences in rates of comorbid psychiatric and medical conditions. Data for all demographic and clinical variables were extracted from deidentified case records of 4,977 clients enrolled in a comprehensive case management program for welfare recipients with substance use disorders. Latent class analysis supported a five-class model made up of a multiple abuse/dependence class (n = 1,133), a cocaine/alcohol class (n = 2,120), an opioids class (n = 1,346), a cannabis class (n = 362), and a small polysubstance/none primary class (n = 16). Post hoc chi-square analyses revealed several between-class differences, perhaps reflecting differing levels of severity and service needs. All five classes were characterized by high rates of medical and psychiatric comorbidity.
Recent progress in rheumatoid arthritis genetics: one step towards improved patient care.

Purpose of reviewRecent human genetic discoveries have increased our understanding of rheumatoid arthritis (RA) susceptibility. These discoveries are reviewed and placed in the context of potential important clinical applications.Recent findingsGenome-wide association studies and related methodologi
Emergency department thoracotomy following injury: critical determinants for patient salvage.

The role of emergency department (ED) thoracotomy in resuscitation of the moribund trauma patient remains ill-defined. The purpose of this article is to analyze our experience during the past decade in order to elucidate prognostic features enabling a more cost-effective application of this heroic measure.
Monolithic Widely Tunable Packet Forwarding Chip in InP for All-Optical Label Switching

In this paper, we describe a monolithically integrated tunable optical packet forwarding chip in InP. The chip consists of a differential Mach-Zehnder Interferometer SOA tunable 40 Gbps wavelength converter integrated with an electro-refractive modulator for 10 Gbps label modulation. Error free performance and dynamic forwarding of asynchronous variable length packets is reported.
Can modifications in surgical technique improve postprostatectomy potency rates in men with prostate cancer

Can modifications in surgical technique improve postprostatectomy potency rates in men with prostate cancer?
Affective and cognitive manifestations of interaction involvement during unstructured and competitive interactions

The construct of interaction involvement was extended in this study by relating scores on the interaction involvement scale to individuals’ experienced mood state and information recall in two different communication settings. Consistent with hypotheses, highly involved persons felt more positive and less negative during an unstructured conversation and recalled more detail about the conversation than low‐involved persons. Similarly, highly involved persons felt more positive and less negative during a competitive negotiation than low‐involved persons. The results were interpreted to suggest that there is a significant affective component in interaction involvement which in part accounts for a disruption in the capacity for intersubjectivity on the part of low‐involved persons.
Comparison of intracoronary gamma radiation for in-stent restenosis in saphenous vein grafts versus native coronary arteries.

Intracoronary gamma radiation is effective in reducing recurrent in-stent restenosis (ISR) involving native coronary arteries. This study compares the effectiveness and safety of intracoronary gamma radiation for the treatment of ISR in saphenous vein grafts (SVGs) versus native coronary arteries. In the Washington Radiation for In-Stent restenosis Trial (WRIST) series of gamma radiation trials, 1,142 patients with ISR (230 in SVG and 912 in native coronary arteries) completed 6-month clinical follow-up. All patients underwent balloon angioplasty, atherectomy, and/or restenting. Different ribbon lengths containing 6 to 23 seeds of iridium-192 were used to cover lesion lengths <80 mm. The prescribed radiation doses were 14 or 15 Gy at 2-mm radial distance from the center of the source. Baseline demographics showed that patients with SVGs were older (65 ± 13 vs 61 ± 11 years, p <0.001), more likely male (79% vs 64%, p <0.001), had more multivessel coronary disease (81% vs 50%, p <0.001), and less diffuse lesions (17 ± 10 vs 24 ± 12 mm, p <0.001). At 6 months, event-free survival was similar for patients with SVG ISR and native coronary ISR (82% vs 84%, p = 0.35). The SVG ISR population had a low rate of late total occlusion (4.6%) and late thrombosis (3.5%). Thus, treatment of ISR with gamma radiation in SVGs had similar outcome to native coronary arteries. The use of gamma radiation for the treatment of ISR should expand to SVGs.
Embracing the social relevance: computing, ethics and the community

We propose the integration of service-learning into the early undergraduate computer science curriculum by way of a course on computing, ethics and society. We believe that such a course will fill a common gap in computer science and can be used to draw smart, motivated students to the discipline by embracing its social relevance. Additionally, we outline a particular service-learning project that can be undertaken by students in the course--initiating a community computer recycling program. We describe the successful implementation of such a recycling program and describe some logistical issues that may arise in organizing such a program in a service-learning course. We believe that a student-implemented community outreach project such as this can alter the public's perception of computer science and will assist in reversing the trend of declining undergraduate enrollment.
Packrat middens from Canyon de Chelly, northeastern Arizona: Paleoecological and archaeological implications

Abstract In western North America, pollen data from highland lakes are often used to reconstruct vegetation on the adjacent lowlands. Plant macrofossils and pollen from packrat middens now provide a means to evaluate such reconstructions. On the basis of pollen diagrams from the Chuska Mountains, H. E. Wright, Jr., A. M. Bent, B. S. Hansen, and L. J. Maher, Jr., ((1973), Geological Society of America Bulletin, 84 , 1155–1180) arrived at conservative estimates for late Pleistocene depression of highland conifers. In their interpretation, a proposed slight depression of 500 m for lower tree line precluded expansion of Pinus ponderosa into elevations now in desertscrub. Instead, it was suggested that pinyon pine and Artemisia occupied the lowland plateaus. Packrat midden records on either side of the Chuskas fail to verify this model. Early Holocene middens from Chaco Canyon, New Mexico, and a terminal Pleistocene midden from Canyon de Chelly, Arizona, show that blue spruce, limber pine, Douglas fir, dwarf juniper, and Rocky Mountain juniper expanded at least down to 1770 m elevation Neither Colorado pinyon nor ponderosa pine was found as macrofossils in the middens. Artemisia pollen percentages are high in the terminal Pleistocene midden, as they are in the Chuska Mountain pollen sequence, suggesting regional dominance by sagebrush steppe. Of 38 taxa identified, only 3 are shared by middens dated 11,900 and 3120 yr B.P. from Canyon de Chelly, indicating a nearly complete turnover in the flora between the late Pleistocene and late Holocene. Although corn was previously thought to have been introduced to the Colorado plateaus after 2200 yr B.P., the midden dated 3120 yr B.P. contains pollen of corn and other indicators of incipient agriculture.
Resources, Races, and Female‐Headed Congregations in the United States

This paper uses the 1998 National Congregations Study (NCS) to investigate the demographic and organizational characteristics of female-headed comgregations in the United States. Our findings significantly extend knowledge about the demographic characteristics of these congregations. Counterintuitively female-led congregations are more likely to be found in urban areas than in other locations, and they are more prevalent among African American congregations -particularly those with no denominational ties- and among ethnically mixed congregations. Our findings also confirm previous research on women clergy which indicates that, compared with congregations led by men, there is a paucity of organizational resources in female-headed congregations.
Behavior of female African elephants (Loxodonta africana) in captivity

Abstract The purpose of this research was to ascertain the repertoire of behavior of female African elephants (Loxodonta africana) in captivity. Seven female African elephants were observed for 558 hours and 22 minutes for a period of one year. This paper gives a detailed description of the activities of the elephants maintained in a relatively restricted environment. Twenty one different kinds of behaviors were observed, 14 of which were considered unique to elephants. The most frequently occurring behavior was the placement of the trunk of one elephant into or near the mouth of another elephant. The activities were discussed in terms of: (1) social behaviors; (2) individual behaviors; (3) biological behaviors; (4) dominance hierarchy; (5) four factors derived by statistical factor analysis.
Global Circumferential Strain by 2-Dimensional Speckle Tracking Method for the Evaluation of the Left Ventricular Function

Background and Objectives: The speckle tracking method using 2-dimensional (2D) echocardiography is not affected by the tethering of neighboring segments and angulation. Global circumferential strain (GCS) of the left ventricle (LV) has been suggested as a systolic index and correlated with LV contractility. The purpose of this study was to investigate whether acute changes in preload affect global circumferential strain and to evaluate the usefulness of GCS by the speckle tracking method. Subjects and Methods: 2D echocardiography was performed in 69 patients with end-stage renal disease before and after hemodialysis to measure the LV end-diastolic volume and LV ejection fraction. 2D images were acquired from the short-axis view of the mid-LV for the evaluation of GCS. Results: Mean LV end-diastolic volume significantly decreased from 91.2±33.3 mL to 72.3±32.0 mL (p< 0.05), and LV ejection fraction decreased from 63.6±13.1% to 60.0±11.2% (p=0.006) after hemodialysis. However, mean GCS showed no significant change after hemodialysis (17.2±5.3% vs. 16.6±4.7%, p=0.13). GCS was found to be well correlated with LV ejection fraction (r=0.54, p<0.05) and peak systolic mitral annular velocity (r=0.46, p=0.000), but not with LV preload (r=0.06, p=0.622). Conclusion: GCS using the speckle tracking method is a useful index for the evaluation of LV systolic function because it is not affected by acute preload change and is correlated with LV ejection fraction and peak systolic mitral annular velocity. (Korean Circ J 2008;38:379-386)
Optimized Design of Regenerative Blowers for Enhanced Efficiency

In this paper, we studied geometric effects of impeller blade angles and hub configurations on the energy conversion efficiency of regenerative blowers, using commercial CAD and CFD software. As a base geometry, a regenerative compressor, that was commercially available with accessible experimental data, was modeled and simulated. Both Pro/Engineering (PTC) and SolidWorks (Solidworks Corp.) were used for 3D geometrical modeling, and ANSYS-CFX (ANSYS, Inc.) was used for CFD flow simulation. The CFD flow simulation was performed at a constant impeller rotational speed of 3600 rpm, while the air flow rates varied from 60, 80, 100, to 120 cfm. The simulation results for the base geometry agree with the experimental data, confirming the validity of the modeling and simulation schemes. For the parametric study of the impeller blade angles and hub configurations for enhanced efficiency, the two geometrical design parameters were systematically investigated to find out optimal efficiency points. The result shows that the protrusion and shape of a hub are more impactful to the pump efficiency than the outflow angles of blades, and enhances the power efficiency more effectively.Copyright © 2010 by ASME
Thermal chemistry of water adsorbed on clean and oxygen-predosed V(100) single-crystal surfaces

The adsorption of water on V(100) single-crystal surfaces was characterized by temperature programmed desorption and X-ray photoelectron spectroscopy. On clean surfaces, the adsorption of water was determined to be dissociative, and dissociation to be favored at low coverages. With the aid of deuterium and 18O isotope labeling, it was found that coadsorbed surface oxygen blocks this dissociation but also opens a new reaction channel that relies on hydrogen bonding to enhance the generation of hydroxide surface species. The new reaction channel is seen throughout all stages of oxygen uptake, even after the formation of a thin surface oxide film. Three water desorption states were identified in the oxygen-treated substrates, corresponding to recombination of hydroxide surface groups, decomposition of hydrogen-bonded stabilized water, and molecular desorption, respectively.
On “The Methodology of Positive Economics”

I. Introduction, 554. — II. Friedman's main thesis evaluated, 556. — III. Other aspects of Friedman's argument considered, 564. — IV. Conclusion, 570.
A Method for the Routine Measurement of Dielectric Photoconductivity

An instrumentation and data reduction technique for the routine analysis of dielectric photoconductivity data has been developed. This technique provides detailed conductivity versus time data during and shortly after an ionizing radiation pulse. Thus, it complements the timeintegral of conductivity technique, which can provide good long-term delayed conductivity data, and it offers some advantages over similar methods developed to measure conductivity. The unique features of this technique include the use of spline functions in the data reduction, the use of a sample designed to provide noise current cancellation, and circuit analysis that includes a mismatched transmission line.
Side view thrombosis microfluidic device with controllable wall shear rate and transthrombus pressure gradient

Hemodynamic conditions vary throughout the vasculature, creating diverse environments in which platelets must respond. To stop bleeding, a growing platelet deposit must be assembled in the presence of fluid wall shear stress (τw) and a transthrombus pressure gradient (ΔP) that drives bleeding. We designed a microfluidic device capable of pulsing a fluorescent solute through a developing thrombus forming on collagen ± tissue factor (TF), while independently controlling ΔP and τw. Computer control allowed step changes in ΔP with a rapid response time of 0.26 mm Hg s−1 at either venous (5.2 dynes cm−2) or arterial (33.9 dynes cm−2) wall shear stresses. Side view visualization of thrombosis with transthrombus permeation allowed for quantification of clot structure, height, and composition at various ΔP. Clot height was reduced 20% on collagen/TF and 28% on collagen alone when ΔP was increased from 20.8 to 23.4 mm Hg at constant arterial shear stress. When visualized with a platelet-targeting thrombin sensor, intrathrombus thrombin levels decreased by 62% as ΔP was increased from 0 to 23.4 mm Hg across the thrombus-collagen/TF barrier, consistent with convective removal of thrombogenic solutes due to pressure-driven permeation. Independent of ΔP, the platelet deposit on collagen had a permeability of 5.45 × 10−14 cm2, while the platelet/fibrin thrombus on collagen/TF had a permeability of 2.71 × 10−14 cm2 (comparable to that of an intact endothelium). This microfluidic design allows investigation of the coupled processes of platelet deposition and thrombin/fibrin generation in the presence of controlled transthrombus permeation and wall shear stress.
Oral antioxidants improve leg blood flow during exercise in patients with chronic obstructive pulmonary disease

The consequence of elevated oxidative stress on exercising skeletal muscle blood flow as well as the transport and utilization of O2 in patients with chronic obstructive pulmonary disease (COPD) is not well understood. The present study examined the impact of an oral antioxidant cocktail (AOC) on leg blood flow (LBF) and O2 consumption during dynamic exercise in 16 patients with COPD and 16 healthy subjects. Subjects performed submaximal (3, 6, and 9 W) single-leg knee extensor exercise while LBF (Doppler ultrasound), mean arterial blood pressure, leg vascular conductance, arterial O2 saturation, leg arterial-venous O2 difference, and leg O2 consumption (direct Fick) were evaluated under control conditions and after AOC administration. AOC administration increased LBF (3 W: 1,604 ± 100 vs. 1,798 ± 128 ml/min, 6 W: 1,832 ± 109 vs. 1,992 ± 120 ml/min, and 9W: 2,035 ± 114 vs. 2,187 ± 136 ml/min, P < 0.05, control vs. AOC, respectively), leg vascular conductance, and leg O2 consumption (3 W: 173 ± 12 vs. 210 ± 15 ml O2/min, 6 W: 217 ± 14 vs. 237 ± 15 ml O2/min, and 9 W: 244 ± 16 vs 260 ± 18 ml O2/min, P < 0.05, control vs. AOC, respectively) during exercise in COPD, whereas no effect was observed in healthy subjects. In addition, the AOC afforded a small, but significant, improvement in arterial O2 saturation only in patients with COPD. Thus, these data demonstrate a novel beneficial role of AOC administration on exercising LBF, O2 consumption, and arterial O2 saturation in patients with COPD, implicating oxidative stress as a potential therapeutic target for impaired exercise capacity in this population.
Design and synthesis of novel pH and temperature sensitive copolymers for injectable delivery

We have developed methods to synthesize a family of novel self-assembling, pH and temperature sensitive water-soluble multiblock copolymers based on poly(ethylene oxide) (PEO) and poly(diethylaminoethylmethacrylate) (PDEAEM) with a variety of nanoarchitectures.. We have developed oxyanionic polymerization techniques to synthesize di-, tri-, and pentablock copolymers of PEO, poly(propylene oxide) (PPO) and PDEAEM, and also random copolymers of poly(ethylene glycol) methyl ether methacrylate and PDEAEM. The pentablock copolymers self-assemble to form nanometer scale micelles in aqueous solutions and above a critical gelation temperature, the micelles entangle and self-assemble to form macroscale thermoreversible water-soluble physical gels. Aqueous solutions of these polymers at room temperatures can be injected into the body where they form physical gels for controlled delivery that eventually dissolve and release the entrapped molecules. They also possess the ability to undergo swelling/syneresis in response to changes in pH. These polymers were characterized by a number of techniques such as NMR, gel permeation chromatography, infrared spectroscopy, etc. Such smart injectable systems could be very useful for insulin in response to glucose changes. These cationic polymers also exhibit complexation with DNA at physiological pH values and are potential as gene therapy vectors.
Occipital condyle fracture in a victim of a motor vehicle collision

Occipital condyle fractures are rarely reported in the Emergency Medicine literature. It is unclear whether these fractures are rare or under-diagnosed. Occipital condyle fractures are associated with high-energy blunt trauma with significant cranial-cervical torque or axial loading. We report a case of a female patient with an occipital condyle fracture. The patient only complained of shoulder pain, but was found to have high cervical spine tenderness, after a moderate-speed front-end motor vehicle collision. Initial cervical spine radiographs were non-diagnostic. Computed tomography of the cervical spine demonstrated a non-displaced occipital condyle fracture. Conservative management with a semi-rigid cervical collar was successful in treating this patient's fracture. A review of the literature covers the diagnosis, radiographic findings, and management of this fracture.
Building better swarms through competition: lessons learned from the AAAI/RoboCup Rescue Robot competition

A common problem in a disaster situation, whether man-made or natural, is the need to quickly identify locations of potential victims and potential hazards to human rescuers, with minimal personnel on site at the beginning of the emergency. Robots can be used to supplement available personnel and to assist them in their search. However, it is important that the robots used not pose a danger to rescuers and victims through collisions or causing structural collapse and that they not get in the way of rescue efforts. Another problem in a disaster area is that environmental conditions (e.g., rubble, scrap metal, dust, smoke, and fire) can make it difficult for robots to maneuver, reduce effectiveness of sensors, and hamper communications. We believe the best approach to developing an effective robotic assistant to human rescue teams is through swarms of low-cost, small robots. The robots should be low cost to eliminate concerns about not recovering them after a disaster. They should be small so they don't hinder or pose a risk to humans (rescuers can kick them or step on them if they are in the way and they will be too small to move objects or injure a person through collision). And we believe a swarm should be used to maximize the area covered while maintaining enough contact between robots to maintain a reliable communications link. A swarm of small robots programmed with simple behaviors can achieve these goals while keeping costs down. This paper describes the efforts we have undertaken at Utah State University in developing urban search and rescue robot swarms for the American Association for Artificial Intelligence and RoboCup Rescue Robot competitions. Both of these competitions make use of the standard urban search and rescue test course developed by the National Institute of Standards and Technology (NIST). Our initial efforts to try to determine the bare minimum competence required for a rescue swarm are described, as are our efforts to improve communications between robots and a base station. Our current efforts to implement a flocking behavior in a robot swarm are described, as is the most recent modular, behavioral robot design we are working on. The development of a graphical user interface for use by rescuers to interface with the swarm is also described. Finally, we discuss the direction we think this research needs to take in the future.
Does loading time affect implant survival? A meta-analysis of 1,266 implants.

Background: Considerable controversy exists as to whether immediate or early implant loading is associated with a higher failure rate compared to conventional loading. Numerous trials conducted have yielded inconsistent results, partly due to low statistical power. Thus, we sought to determine whether combining results from all published trials would provide a better estimate of the impact of implant loading time on survival. Methods: We carried out a meta-analysis of all previously published prospective trials comparing conventional with early or immediate implant loading. The outcome of interest was implant failure rate. The Q statistics test was used to assess the presence of heterogeneity. We identified relevant studies through a search of the MEDLINE database and the Cochrane Registry of Controlled Trials. Results: We found 13 prospective trials (1,266 implants) in which early or immediate implant loading was compared to conventional loading. Overall there was no difference in implant failure rate be...
Moving overlapping grids with adaptive mesh refinement for high-speed reactive and non-reactive flow

We consider the solution of the reactive and non-reactive Euler equations on two-dimensional domains that evolve in time. The domains are discretized using moving overlapping grids. In a typical grid construction, boundary-fitted grids are used to represent moving boundaries, and these grids overlap with stationary background Cartesian grids. Block-structured adaptive mesh refinement (AMR) is used to resolve fine-scale features in the flow such as shocks and detonations. Refinement grids are added to base-level grids according to an estimate of the error, and these refinement grids move with their corresponding base-level grids. The numerical approximation of the governing equations takes place in the parameter space of each component grid which is defined by a mapping from (fixed) parameter space to (moving) physical space. The mapped equations are solved numerically using a second-order extension of Godunov's method. The stiff source term in the reactive case is handled using a Runge-Kutta error-control scheme. We consider cases when the boundaries move according to a prescribed function of time and when the boundaries of embedded bodies move according to the surface stress exerted by the fluid. In the latter case, the Newton-Euler equations describe the motion of the center of mass of the each body and the rotation about it, and these equations are integrated numerically using a second-order predictor-corrector scheme. Numerical boundary conditions at slip walls are described, and numerical results are presented for both reactive and non-reactive flows that demonstrate the use and accuracy of the numerical approach.
Gate sizing using incremental parameterized statistical timing analysis

As technology scales into the sub-90 nm domain, manufacturing variations become an increasingly significant portion of circuit delay. As a result, delays must be modeled as statistical distributions during both analysis and optimization. This paper uses incremental, parametric statistical static timing analysis (SSTA) to perform gate sizing with a required yield target. Both correlated and uncorrelated process parameters are considered by using a first-order linear delay model with fitted process sensitivities. The fitted sensitivities are verified to be accurate with circuit simulations. Statistical information in the form of criticality probabilities are used to actively guide the optimization process which reduces run-time and improves area and performance. The gate sizing results show a significant improvement in worst slack at 99.86% yield over deterministic optimization.
Scavenger receptor B1 facilitates macrophage uptake of silver nanoparticles and cellular activation

Due to increased use of silver nanoparticles (AgNPs) for their antimicrobial activity, concerns have risen regarding potential adverse human health effects. Scavenger receptor B1 (SR-B1), a major receptor for high-density lipoprotein (HDL), is expressed by macrophages and has also been reported to play a role in recognition of negatively charged particles. We, therefore, hypothesized that SR-B1 mediates macrophage uptake of AgNPs and inflammatory activation. To test this hypothesis, we exposed a mouse macrophage cell line RAW264.7 (RAW) and bone marrow-derived macrophages (BMDM) to 20 nm citrate-suspended AgNPs. To verify the role of the SR-B1 receptor, we utilized a SR-B1 inhibitor (Blt2). In vitro studies demonstrated uptake of AgNPs and HDL-coated AgNPs by macrophages which were significantly reduced following pretreatment with Blt2. Inflammatory cytokine arrays revealed that macrophages exposed to AgNPs up-regulated expression of Tnf-α, Oncostatin m (OSM), Ccl4, Il17f, Ccl7, and Ccl2, whereas Il16 was found to be down-regulated. Macrophage activation was observed following AgNP and HDL-coated AgNP exposure as measured by OSM protein production and increased surface expression of CD86. These markers of activation were reduced with Blt2 pretreatment. The in vitro findings were confirmed in vivo through pulmonary instillation of AgNPs in mice. Pulmonary instillation of AgNPs resulted in a recruitment of inflammatory cells that were reduced in SR-B1-deficient mice or following Blt2 pretreatment. This study suggests that SR-B1 plays a major role in cellular recognition of AgNPs and the induction of cell responses that could contribute to inflammation caused by AgNP exposure.
Polishness of the Wijsman Topology Revisited

Let X be a completely metrizable space. Then the space of nonempty closed subsets of X endowed with the Wijsman topology is a-favorable in the strong Choquet game. As a consequence, a short proof ofthe Beer-Costantini Theorem on Polishness of the Wijsman topology is given.