cssi/SciSciGPT-SciSciNet huggingface dataset:
Are technetium-99m-labeled myocardial perfusion agents adequate for detection of myocardial viability?

The noninvasive assessment of myocardial viability in patients with coronary artery disease and depressed left ventricular function has proven clinically useful for identifying those patients with ischemic cardiomyopathy who benefit most from coronary revascularization. Thallium-201 ( 201 T1) imaging at rest has been the radionuclide imaging technique most often utilized for distinguishing viable myocardium from scar. However, new technetium-99m ( 99m Tc) perfusion agents such as 99m Tc-sestarnibi and 99m Tc-tetrofosmin have emerged as alternatives to 201 T1 for imaging of regional myocardial perfusion. Whether these new agents, which have better physical properties for imaging with a gamma camera than 201 T1, are valid for use in assessing myocardial viability is still uncertain. Recent clinical studies have demonstrated that these agents, when imaged using quantitative SPECT, can identify patients with myocardial hibernation who exhibit improved regional systolic function following revascularization. Experimental laboratory studies have shown that the uptake of 99m Tc-sestamibi and 99m Tc-tetrofosmin in ischemic myocardium is only slightly lower than the uptake of 201 T1. These 99m Tc-labeled agents remain bound intracellularly in mitochondria of viable myocytes under conditions of myocardial stunning and short-term hibernation, producing severe myocardial asynergy. With respect to determination of viability, the inferior wall region is at times problematic since attenuation of 99m Tc-sestamibi and 99m Tc-tetrofosmin is greatest in this area. Demonstration of preserved systolic thickening on ECG-gated SPECT images is indicative of viability in the instance of decreased regional 99m Tc counts due to attenuation and not scar. Administration of nitrates prior to tracer injection improves the sensitivity for identifying viable myocardial segments using rest imaging with 99m Tc-sestamibi or 99m Tc-tetrofosmin. Thus, it appears that the new 99m Tc perfusion imaging agents can be successfully employed for the determination of myocardial viability in the setting of severe regional dysfunction and chronic coronary artery disease. The greater the myocardial uptake of these agents in the resting state, the greater the probability of improved systolic function after coronary revascularization.
Aerial observations of the evolution of ice surface conditions during summer

[1] During spring and summer, the Arctic pack ice cover undergoes a dramatic change in surface conditions, evolving from a uniform, reflective surface to a heterogeneous mixture of bare ice, melt ponds, and leads. This transformation is accompanied by a significant decrease in areally averaged, integrated albedo. The key factors contributing to this reduction in albedo are the melting of the snow cover, the formation and growth of the melt ponds, and the increase in the open water fraction. To document these changes and enable quantification of the evolution of the ponds throughout the melt season, a program of aerial photography was carried out at the main site of the Surface Heat Budget of the Arctic Ocean (SHEBA) program. A modified square pattern, 50 km on a side, surrounding the SHEBA site was flown at altitudes ranging from 1220 to 1830 m. Twelve of these aerial survey photography flights were completed between 20 May and 4 October 1998. The flights took place at approximately weekly intervals at the height of the melt season, with occasional gaps as long as 3 weeks during August and September due to persistent low clouds and fog. In addition, flights on 17 May and 25 July were flown in a closely spaced pattern designed to provide complete photo coverage of a 10-km square centered on the SHEBA main site. Images from all flights were scanned at high resolution and archived on CD-ROMs. Using personal computer image processing software, we have measured ice concentration, melt pond coverage, statistics on size and shape of melt ponds, lead fraction, and lead perimeter for the summer melt season. The ponds began forming in early June, and by the height of the melt season in early August the pond fraction exceeded 0.20. The temporal evolution of pond fraction displayed a rapid increase in mid-June, followed by a sharp decline 1 week later. After the decline, the pond fraction gradually increased until mid-August when the ponds began to freeze. By mid-September the surface of virtually all of the ponds had frozen. The open water fraction varied between 0.02 and 0.05 from May through the end of July. In early August the open water fraction jumped to 0.20 in just a few days owing to ice divergence. Melt ponds were ubiquitous during summer, with number densities increasing from 1000 to 5000 ponds per square kilometer between June and August.
Mouse mammary tumor virus gene expression regulated in trans by Lps locus

Expression of mouse mammary tumor virus (MMTV) in the lactating mammary glands of uninfected mice varies between strains of mice in a manner largely independent of the proviral content. Previous linkage analysis in the mouse suggested that the Lps locus was associated with steady-state levels of MMTV RNA. The Lps locus mediates the mouse's response to the injection of lipopolysaccharide (LPS) in the responder mouse while mice with the deficient allele are incapable of responding. Injecting LPS-responder mice, C3HfB/HeN, and nonresponder mice, C3Hf/HeJ, with LPS resulted in a threefold increase in the level of MMTV RNA in responder mice but had no effect on nonresponders. The increased level was due to only one of the possible MMTV transcripts: the 1.7-kb transcript containing the open reading frame (orf) of the long terminal repeat (LTR). The level of MMTV-specific transcripts, then, is regulated by the Lps locus, a cellular gene which is not linked to any viral coding sequences and therefore must act in trans.
On the oxidation of cyanides in the stack region of the blast furnace

Computed results are reported on the oxidation of KCN particles carried by blast furnace gas through the stack region of the furnace. The calculations were performed on the assumption that the oxidation process is mass transfer controlled, but proper allowance was made for the variable CO/CO2 ratios and temperatures to which the particles are exposed during their passage through the stack. The results of these calculations show that for cyanide particles in the range 0.02 to 0.1 cm in diameter the system may be extremely sensitive both to the temperature profiles and to the CO/CO2 ratios within the stack; thus the control of these parameters could provide a means of controlling cyanide emissions.
Effects of Alternative Metal Working Fluids Upon Tool Face Wear

Orthogonal metal cutting allows the collection of force data in the laboratory in an analytical manner not practical during industrial applications. Orthogonal tube turning (OTT) allows the collection of force data at much higher speeds than the original methods used by Ernst and Merchant. An orthogonal tube turning apparatus was constructed and validated in order to study the effects of rake angle, uncut chip thickness and cutting environments on the tool forces and the wear of the tool face itself. Although there have been many studies which characterized the forces and the surface finish of the part machined, along with some version of tool life, this study is unique in that the wear of the tool face itself is characterized in a detailed analysis of variance (ANOVA) study. A widely utilized commercial water based product performed less well than either nitrogen gas or cold shop compressed air. Surface roughness of the tool was used to parameterize tool surface finish for cutting each factor level combination of the experiment.Copyright © 2010 by ASME
Beta-adrenergic blocking agents: past, present, and future perspectives.

The 'proof of concept' of beta-blockade for heart failure (i.e. that the pharmacologic actions of beta-blockers are beneficial) is now firmly established, as the treatment of heart failure has progressed from using positive inotropic stimulation, via drugs with no direct effect on cardiac function, to beta-blockers with negative intropic effects. This review addresses some remaining issues regarding beta-blockade in heart failure. The mechanism of action of beta-blockers in heart failure is more likely to be improved intrinsic cardiac myocyte function and prevention or reversal of remodeling, than restoration of beta-adrenergic signal transduction. The role of the differentiating characteristics of beta-blockers is not clear at this time, and there is no compelling evidence to select one agent over another on the basis of individual drug properties. Recent reports suggest that beta-blockers reduce the combined risk of all-cause mortality and hospitalizations by about 30-35%. These results are heavily influenced by experience with carvedilol, but other agents tested include metoprolol, bucindolol, bisoprolol, and nebivolol. Responsiveness to beta-blockers is not related to patients' age, sex, or race, or to the etiology or severity of heart failure. Beta-blockers are currently recommended as adjunctive treatment in patients who remain mildly to moderately symptomatic while receiving added digitalis, diuretics, and angiotensin-converting enzyme inhibitors. Existing gaps in our knowledge must be filled in order to achieve optimal clinical application of beta-blockers. Ongoing studies will provide much of the information required. The role of beta-blockers will probably expand as we improve our understanding of the pathophysiology of heart failure, and especially of the remodeling process.
Extending the stress-analysis range of brittle coatings

In this paper, an attempt is made to extend in both directions the range of the stresses that can be determined using brittle coatings: (1) by sensitizing the coating to determine small stresses, and (2) by the use of a new calibration device that allows the application of very large strains.
Brain and testicular function

Abstract Plasma and testicular testosterone levels can fluctuate rapidly under the influence of C.N.S. events. Both acute and chronic stress, as well as sexual satiety, will reduce testicular function in rodents whereas sexual excitation will increase it. Catecholamine and serotonin neurones appear to participate in the regulation of the pituitary-testicular system.
The effects of phenylpropanolamine on dietary intake, physical activity, and body weight after smoking cessation

This investigation evaluated the effect of phenylpropanolamine on the weight gain associated with 2 weeks of abstinence from smoking. Subjects were 57 adult female cigarette smokers who were randomly assigned, in a double-blind procedure, to chew gum with phenylpropanolamine or placebo gum, or to chew no gum. After a baseline assessment, subjects were paid to quit smoking for a period of 2 weeks. Forty-one (72%) of the 57 subjects were successful in quitting smoking for the 2-week period. Results indicated that, relative to the other two conditions, abstinent subjects receiving phenylpropanolamine gained 1.5 to 1.9 pounds less weight (p less than 0.05). In addition, abstinence rates were higher (p less than 0.03) and dietary intake lower for subjects receiving phenylpropanolamine (p less than 0.05) relative to the other two conditions. No changes in physical activity were observed. It is concluded that phenylpropanolamine may help reduce weight gain associated with smoking abstinence and in this way may enhance smoking cessation efforts in certain individuals.
Mapping the body representation in the SI cortex of anesthetized and awake rats

We have used single unit recording techniques to map the representation of cutaneous and joint somatosensory modalities in the primary somatosensory (SI) cortex of both anesthetized and awake rats. The cytoarchitectonic zones within the rat SI were divided into the following main categories: (1) granular zones (GZs)--areas exhibiting koniocortical cytoarchitecture (i.e., containing dense aggregates of layer IV granule cells), (2) perigranular zones (PGZs)--narrow strips of less granular cortex surrounding the GZs, and (3) dysgranular zones (DZs)--large areas of dysgranular cortex enclosed within the SI. The narrow strip between the SI and the rostrally adjacent frontal agranular cortex was termed the "transitional zone" (TZ). Initial computer-based studies of the properties of cutaneous receptive fields (RFs) in SI showed that, although there were differences in response threshold, adaptability, frequency response, and overall RF size and shape of adjacent neurons, the size and location of the "centers" of the RFs were quite constant and were similar to those seen in multiple unit recordings. The same was true of RFs of single neurons recorded through different anesthetic states. The body representation in SI was first mapped by determining single unit and unit cluster RFs within a total of 2,170 microelectrode penetrations in barbiturate-anesthetized rats. Cutaneous RFs in the GZs were quite discrete. Thus, a single, finely detailed, continuous map of the cutaneous periphery was definable within the GZs themselves. Only the forepaw had a double representation. RFs in the PGZs were larger and more diffuse, but since they covered roughly the same skin areas as the RFs in the most closely adjacent GZs, they fit into the same body map. Neurons in the DZs were unresponsive to any sensory stimuli in the anesthetized animal. In chronically implanted, freely moving, awake animals cutaneous RFs were larger and more volatile than in the anesthetized, but the accuracy of the map was clearly preserved by the fact that the locations of the RF centers (which often must be defined quantitatively) were unchanged. The PGZs and DZs in the awake animals exhibited a multimodal convergence of cutaneous and joint movement RFs within single vertical penetrations, or even on single neurons. Directionally specific and bilateral cutaneous RFs were also observed in the DZs. It was concluded the DZs are more associational or integrative areas within the SI, but they could not be shown to comprise a distinct and separate body representation.(ABSTRACT TRUNCATED AT 400 WORDS)
Reroute on loop in anonymous peer-to-peer content sharing networks.

Detecting and handling routing loops is a critical issue in the design of anonymous peer-to-peer content sharing networks (apCSNs). A principal requirement of such a scheme is that it should not leak any message forwarding information that can undermine the user anonymity of the resulting apCSN. A number of loop handling schemes have been developed in apCSNs such as Freenet and GNUnet. However, they all leak certain level of message forwarding information, which can be exploited to undermine or compromise the user anonymity. In this paper we develop a new loop handling scheme named Reroute-on-Loop (ROL) that will not leak any message forwarding information. Using the Thynix simulator developed by the Freenet project, we show that overall ROL only has minor performance impacts on message path lengths compared to the current loop handling scheme of Freenet on various network topologies, ranging from small-world topologies to random topologies. For example, the average routing path lengths of ROL are only increased by less than 1 hop compared to those with the current loop handling scheme of Freenet on small-world network topologies. Our performance studies confirm that ROL is a practical scheme, and can be deployed on Freenet and similar apCSN systems.
On the validity of Freud’s dream interpretations

In this article I defend Freud's method of dream interpretation against those who criticize it as involving a fallacy-namely, the reverse causal fallacy-and those who criticize it as permitting many interpretations, indeed any that the interpreter wants to put on the dream. The first criticism misconstrues the logic of the interpretative process: it does not involve an unjustified reversal of causal relations, but rather a legitimate attempt at an inference to the best explanation. The judgement of whether or not a particular interpretation is the best explanation depends on the details of the case in question. I outline the kinds of probabilities involved in making the judgement. My account also helps to cash out the metaphors of the jigsaw and crossword puzzles that Freudians have used in response to the 'many interpretations' objection. However, in defending Freud's method of dream interpretation, I do not thereby defend his theory of dreams, which cannot be justified by his interpretations alone.
CdTe as a gamma detector

Abstract Carrier trapping effects dominate the response of semi-insulating CdTe and GaAs to nuclear particles. Photopeaks can be resolved with degraded resolution under conditions of less than full collection.
Identification of the human methylmalonyl-CoA racemase gene based on the analysis of prokaryotic gene arrangements. Implications for decoding the human genome.

Abstract In this report, we identify the humandl-methylmalonyl-CoA racemase gene by analyzing prokaryotic gene arrangements and extrapolating the information obtained to human genes by homology searches. Sequence similarity searches were used to identify two groups of homologues that were frequently arranged with prokaryotic methylmalonyl-CoA mutase genes, and that were of unknown function. Both gene groups had homologues in the human genome. Because methylmalonyl-CoA mutases are involved in the metabolism of propionyl-CoA, we inferred that conserved neighbors of methylmalonyl-CoA mutase genes and their human homologues were also involved in this process. Subsequent biochemical studies confirmed this inference by showing that the prokaryotic gene PH0272 and its human homologue both encode dl-methylmalonyl-CoA racemases. To our knowledge this is the first report in which the function of a eukaryotic gene was determined based on the analysis of prokaryotic gene arrangements. Importantly, such analyses are rapid and may be generally applicable for the identification of human genes that lack homologues of known function or that have been misidentified on the basis of sequence similarity searches.
Is user satisfaction a valid measure of system effectiveness

User satisfaction (US) is often used as a surrogate measure of information system effectiveness. If an effective system is defined as one that adds value to the firm, then an effective system must have some positive influence on user behavior (i.e., improve productivity, decision making, etc.). Advocates of US argue that there is theoretical support for linking attitudes (i.e., satisfaction) and behavior in the psychology literature. At the same time, there is evidence of increasing employment of US questionnaires in firms as a measure of system effectiveness. Yet there is surprisingly little information systems research linking user satisfaction with user behavior. In this study, measures of user satisfaction and system affected behavior are taken for an indirect and a direct user group of the same information system in 39 organizations. Results indicate that a relationship does exist between satisfaction and behavior for both user groups.
Initial and delayed right ventricular thallium-201 rest-imaging following dipyridamole-induced coronary vasodilation: relationship to right coronary artery pathoanatomy.

The relationship of coronary anatomy to right ventricular (RV) appearance on serial thallium-201 myocardial imaging (TI) following dipyridamole (DP)-induced coronary vasodilation was examined in 71 consecutive patients undergoing coronary angiography for the evaluation of chest pain. Transient defects of the RV were found in 18 patients. All 18 had significant (≥ 50%) stenosis of the proximal right coronary artery (RCA). Nonvisualization of RV activity occurred in 13 patients. Six of these 13 (46%) had proximal RCA disease (p < 0.05 compared to transient defects). Normal RV appearance was seen in 40 patients, of whom only six (15%) had proximal RCA disease (p < 0.001 compared to transient defects). RV appearance was not affected by left anterior descending or left circumflex artery disease or by the thallium-201 uptake in the left ventricle. Thus with serial (initial and delayed) TI following DP (1) a transient RV defect appears to indicate significant proximal RCA disease; (2) normal RV appearance suggests the absence of proximal RCA disease; and (3) however, nonvisualization of the RV appears to be nondiagnostic.
Cohesion Versus Structural Equivalence as a Basis for Network Subgroups

Two basic approaches to network analysis are compared in terms of the network subgroups each produces. The relational approach, developing from traditional sociometry, focuses on relations between ...
Ifosfamide: chemotherapy with new promise and new problems for the urologist.

Abstract Ifosfamide, a chemotherapeutic agent, offers new hope as well as new problems for the uro-oncologist. The “good news” is that this drug is achieving marked benefits in treating resistant testis tumors and may even hold hope for patients with renal cell carcinoma. The “bad news” is that a price must be paid in toxicity-predominantly a severe and restrictive hemorrhagic cystitis. A breakthrough is the finding that oral administration of acetylcysteine (Mucomyst) may, to a large extent, prevent this untoward side effect.
Revisiting the thetic/categorical distinction in Japanese

In this study, I propose a refinement of Kuroda’s (1972, 1990) claim that the categorical and thetic judgments are realized syntactically in Japanese. Succinctly put, Kuroda argues that sentences with the topic marker wa represent categorical judgments whereas those with the nominative marker ga represent thetic judgments. In the present study, I demonstrate that wa-sentences do not uniformly represent categorical judgments and that ga-sentences do not represent thetic judgments across the board either. In particular, I argue that ga-sentences represent thetic judgments only on the so-called "neutral-description" reading (in the sense of Kuno 1973); on the "exhaustive-listing" reading, they instead involve categorical judgments. In addition, I demonstrate that wa-sentences also require a parallel refinement: thematic wa vs. contrastive wa. I therefore propose a four-way distinction and further demonstrate that the four readings are interrelated through different types of judgments as follows: thematic wa and exhaustive-listing ga involve categorical judgments whereas contrastive wa and neutral-description ga involve thetic judgments.
Awake at 4 a.m.: Treatment of Insomnia With Early Morning Awakenings Among Older Adults

Insomnia is a common problem among older adults. In particular, older adults experience insomnia coupled with early morning awakenings due to an interaction between age-related changes in circadian rhythm timing coupled with behavior changes that contribute to sustained poor sleep. Cognitive-behavioral therapy for insomnia (CBT-I), at times coupled with circadian interventions (e.g., timed light exposure), are likely to be most successful in optimizing sleep quality. In delivering CBT-I to older adults, modifications are sometimes necessary to accommodate for medical problems, lifestyle, social factors, and patient preferences. Addition of circadian interventions can ameliorate the negative effects of inappropriately timed sleep as well. These treatment methods can be highly effective and benefits can be long-standing. A case example is used to illustrate these points.
Layered manufacturing technologies

From the holodeck in "Star Trek" to the slice-by-slice reconstruction of the alien Leeloo played by actress Milla Jovovich in the movie The Fifth Element, science fiction has long predicted the possibility of automated one-off construction of the most complex objects from a stream of digital information. While we are still a long way from being able to build living beings in this manner, digitally controlled layered manufacturing (LM) technologies are transforming prototyping and mass customization of mechanical and biomedical parts of extraordinary geometric complexity.
PSYCHOTHERAPY APPROACHES FOR ADULT SURVIVORS OF CHILDHOOD SEXUAL ABUSE: AN INTEGRATIVE REVIEW OF OUTCOMES RESEARCH

This review synthesized results of 26 outcomes research studies and two meta-analyses that evaluated abuse-focused psychotherapy techniques for survivors of childhood sexual abuse. Different therapeutic approaches delivered in individual, group, or combination formats were evaluated with pre/post test, quasi-experimental, or randomized control designs. Accumulated research findings suggest that abuse-focused psychotherapy for adults sexually abused as children is generally beneficial in reducing psychiatric distress, depression, and trauma-specific symptoms. No one therapeutic approach was demonstrated to be superior. There was little evidence about the effectiveness of individual versus group therapy or the optimal treatment duration.
Noninsulin pharmacological management of type 1 diabetes mellitus

The injectable nature and other shortcomings of insulin have stimulated interest in studying the noninsulin pharmacological therapies to manage type 1 diabetes mellitus (T1DM). The purpose of this study is to conduct a systematic literature review of noninsulin pharmacological therapies for the management of T1DM. For this, the following PubMed search was conducted: Diabetes Mellitus, Type 1/therapy”[Mesh] Limits: Review Sort by: Publication Date. After applying various inclusion and exclusion criteria, a total of 63 studies were reviewed. Based on this review, noninsulin pharmacological therapies can be divided into following classes: (1) Insulin-sensitizing agents (biguanides and thiazolidinediones), (2) gastrointestinal nutrient absorption modulators (α-Glucosidase inhibitors and amylin), (3) immunotherapeutic agents, (4) incretin-based therapies, (5) recombinant human insulin-like growth factors, and (6) other promising therapeutics. Some of these are already used either as monotherapy or adjuvant to insulin, whereas, to manage T1DM, the benefits and risks of the others are still under evaluation. Nonetheless, insulin still remains the cornerstone to manage the T1DM.
On the roughening of solid surfaces

Abstract Two roughening phenomena are discussed. The kink-driven line roughening of high-indexed surfaces (such as fcc(113), (115) and (117), discussed in various papers recently) is presumably undergoing an Ising-type transition in contrast to the step-driven surface roughening which shows either a Kosterlitz-Thouless-type infinite-order phase transition, or, depending on the step energy parameters, a smooth cross-over only.
Distribution of Foraminifera and Sediments, Peru-Chile Trench Area: ABSTRACT

Nineteen trawl samples and 13 trigger cores were collected between depths of 179 and 6,250 m. in the Peru-Chile trench area off the western coast of South America. Sediments are mainly olive-green silt, clay, and colloidal material; however, four cores contain significant amounts of either sand-size Foraminifera or shale fragments, and one of these cores is mainly white volcanic ash. Values for organic carbon and nitrogen are much higher in the bathyal than in the abyssal zone. Sediment grain sizes do not exhibit definitive trends with either water depth or distance from shore. Calcium carbonate content decreases sharply below 3,500 m., reflecting reduced quantities of calcareous Foraminifera in the trench. Deeper than 1,500 m., radiolarians are commonly more than twice as abundant as Foraminifera. Foraminifera larger than 0.5 mm. were concentrated in the trawl samples and below 1,000 m. are dominantly arenaceous. Among smaller Foraminifera, calcareous forms predominate down to 2,000 m.; at greater depths calcareous- arenaceous ratios fluctuate greatly. Planktonic foraminiferal tests are most abundant in the bathyal zone. Bathymetric foraminiferal zonation is based upon upper limits of occurrence for both the larger live End_Page 1756------------------------------ Foraminifera from the trawls and the smaller Foraminifera from the cores. Maximum size of the larger Foraminifera usually is between 1-10 mm. The zonation is: Table Estimates of the total volumes of material caught by each trawl range from 2 to about 43 kg., dry weight. End_of_Article - Last_Page 1757------------
Comparison of the Strain Localization Approaches: Viscoplasticity Theory and Gradient Dependent Theory

This work is focused on the comparison between the two strain localization techniques namely, the viscoplasticity and the gradient dependent theory. In the first approach a length-scale parameter is introduced implicitly through viscosity in order to address strain localization and material instability in the (initial) boundary value problems. The second approach is the enhanced nonlocal gradient-dependent theory which formulates a constitutive framework on the continuum level that is used to bridge the gap between the micromechanical theories and the classical (local) continuum. It is successful in explaining the size effects encountered at the micron scale and in preserving the well-posedeness of the (initial) boundary value problems governing the solution of material instability triggering strain localization. This is due to the explicit incorporation of an intrinsic material length scale parameter in the constitutive description. These numerical examples prove the excellent performance of the present frameworks in describing the strain localization problem.Copyright © 2005 by ASME
Transport and countertransport of thymidine in ATP depleted and thymidine kinase‐deficient novikoff rat hepatoma and mouse L cells: Evidence for a high Km facilitated diffusion system with wide nucleoside specificity

Incubation of cultured Novikoff rat hepatoma and mouse L cells in a glucose-free basal medium containing 5 mM KCN and 5 mM iodoacetate for about 10 minutes resulted in a complete depletion of the cells of ATP. ATP-depleted wild type cells or thymidine kinase-deficient sublines of Novikoff or L cells took up thymidine rapidly from the medium without concentrating it intracellularly, and exhibited countertransport of thymidine. Thus uptake was by facilitated diffusion. This transport system differs from the substrate-specific, low-Km (0.5 muM] thymidine transport system previously described for various types of cultured cells in that it exhibits an at least 100-fold higher Km and transports equally well various ribo- and deoxyribonucleosides. The results suggest that the rate-limiting step in thymidine incorporation into the nucleotide pool by wild type cells is phosphorylation rather than transport, or that the cells possess two transport systems, a facilitated diffusion system with low substrate specificity and a second system which involves substrate phosphorylation by thymidine kinase.
Controlled synthesis of iron oxide nanoplates and nanoflowers

An effective approach to synthesizing crystalline iron oxide nanoplates (∼3 nm thick) and nanoflowers composed of ∼5 nm small grains was reported. The formation of different-shaped nanoparticles in a similar system was achieved by controlling the nucleus concentration and growth rate.
Evidence-based ethics in the gray zone of neonatal viability: promises and limitations

The term ‘evidence-based ethics’ was coined by Tyson to describe the use of specific and detailed outcome data to guide decision making surrounding the provision of neonatal intensive care to infants of borderline viability. Recently, developed prognostic models using factors such as birthweight, gender, multiple birth and antenatal corticosteroid exposure, in addition to gestational age may help refine estimates of prognosis. We will argue that such estimates may help refine the boundaries of the gray zone of infant viability, in which the prognosis is uncertain or guarded enough that parental authority should take precedence in decision making regarding neonatal resuscitation. We will also examine the evidence for applying immediate postnatal factors, such as initial infant heart rate, to determine the appropriateness of resuscitation and conclude that there are few postnatal factors that should alter resuscitation decisions made in concert with the parents prior to delivery.
Local pressure effects on vitreous kinetics

Fluorescein (F) or carboxyfluorescein (CF) was injected subconjunctivally in rabbits and its penetration into and subsequent loss from the vitreous body and anterior segment was measured. Pressure was applied over the site of the injected dye, sufficient to close down the local choroidal circulation. This raised the penetration of F about 30 times and delayed its loss, and raised the penetration of CF about seven times without affecting its loss rate. Cooling the tissue, in addition to local pressure, had little additional effect on the penetration. When F was made to penetrate by transcleral iontophoresis, pressure over the site had no effect on its kinetics. This behavior was compared with the predictions by a mathematical model in which the dye was released as a pulse at the inside of the retina and then diffused freely in the vitreous, loss occurring at the retinal surface by an outward transport process. Two experimental observations, the time at which the fluorescence behind the lens reached its peak and its subsequent loss rate, were related in a graphical representation to two physiological parameters, the rate of diffusion of the dye in the vitreous body and the outward permeability of the retinal layer. In some sets of experiments, particularly those in which iontophoresis was used, the kinetics conformed well to the predictions of this model. In other cases, the agreement was poor, and mechanisms such as storage of dye in the retina and its penetration into the vitreous by an anterior pathway appear to play a role.
In-vitro study of the cellular control of 18F uptake in the enamel of developing rat molar teeth

Abstract Molar expiants from 6-day-old rats were cultured for 4 h in medium containing approx. 2μCi/ml 18 F. Control-cultured expiants were compared to their contralateral pairs which had been subjected to: (1) the enamel organ removed prior to incubation; (2) the expiants heat-treated (65 °C for 10 min); or (3) a metabolic inhibitor, 5mM dinitrophenol (DNP), added to the medium. The Ca concentration of the medium indicated that the expiants became mineralized during incubation. Both removal of enamel organ and heat-treatment enhanced uptake of 18 F from the medium. DNP had no consistent effect. As the pattern of 18 F uptake was similar to that for net Ca uptake by mineralizing enamel, the findings suggest that there is no direct cellular control of F − flux through the enamel organ during the secretory phase of enamel formation.
Field ionization of ozone

Abstract Experimental results on the field ionization of ozone at an iridium surface using a magnetic sector atom-probe FIM show that at the lowest field of ~1.5 V/A only 25% of all ions produced are O+3, while O+2 and a small percentage of O+ indicate field induced dissociation of ozone and recombination of atomic oxygen into O2. At high fields and free space ionization, O+2 is predominant, while the atomic oxygen as a dissociation product escapes without being ionized and cannot be detected. Using pure oxygen as an imaging gas in the FIM, O+2 ions do not dissociate under the same conditions.
Retrieval of an Aspirated Bullet Fragment by Flexible Bronchoscopy in a Mechanically Ventilated Patient

We report the case of a 28-year-old man who aspirated a bullet fragment following a gunshot. Review of the literature indicates this to be a rare finding. Bedside flexible bronchoscopy provided visualization of the foreign body and facilitated its removal while the patient was on a ventilator. The benefits of flexible bronchoscopy in similar conditions are discussed.
Alfalfa root and shoot mulching effects on soil hydraulic properties and aggregation.

Although alfalfa (Medicago sativa L.) stands have been reported to improve soil physical properties, little is known about the specific influences of above- and belowground alfalfa components on soil physical properties. A 2-yr study was conducted to investigate alfalfa root and shoot mulch modifications of soil physical properties and water movement in the root zone of a Kalamazoo loam soil (fine-loamy, mixed, mesic Typic Hapludalf) in southwest Michigan. Four treatments were considered: bare fallow (BF), bare fallow with alfalfa shoot mulch (BFSM), alfalfa with shoots removed and roots remaining (AR), and alfalfa with alfalfa shoot mulch (ASM). Volumetric soil water contents were measured by time domain reflectometry (TDR). Development of fine roots was monitored by minirhizotron technology. Alfalfa root systems increased saturated hydraulic conductivity (K sat ) by 57%, total and macroporosities by 1.7 and 1.8%, respectively, and water recharge rate of the soil profile by as much as 5.4% per day. These effects of alfalfa roots on soil porosity were mainly attributed to increased amplitudes of wetting and drying cycles and high rates of root turnover in the Ap horizon. K sat was significantly correlated with macroporosity (r = 0.90, P ≤ 0.01). Mean weight diameter (MWD) of aggregates from hare fallow soils was 20% higher when alfalfa shoot mulch was applied. Our results suggest that aggregate stability was more affected by C sources from shoot mulch and root turnover than by factors specific to root activities such as physical enmeshment of aggregates and increased soil wetting and drying cycles.
Understanding the Relationship between Language Proficiency, Language Impairment and Rehabilitation: Evidence from a Case Study.

The goal of this study was to address the relationship between language proficiency, language impairment and rehabilitation in bilingual Russian-English individuals with aphasia. As a first step, we examined two Russian-English patients' pre-stroke language proficiency using a detailed and comprehensive language use and history questionnaire and evaluated their impairment using the Bilingual Aphasia Test. We then attempted to replicate and extend Kiran and Roberts' study in 2010, examining results of a primarily semantic treatment for anomia in one Russian-English bilingual patient. The patient's ability to name the trained and untrained items in both the trained (English) and untrained (Russian) languages significantly improved by achieving 100% accuracy. Finally, we examined whether improvements observed in treatment were captured by a broader language test such as the Bilingual Aphasia Test. Results are discussed with respect to factors contributing to the successful treatment and the implications of rehabilitation on assessment of language skills as a function of treatment.
Novel Applications in Pediatric Emergency Ultrasound

New indications for bedside emergency ultrasound are consistently being described in the literature. In recent years, emergency ultrasound has been used in the diagnosis of ocular trauma, the measurement of optic nerve sheath diameter as a surrogate for intracranial pressure, the confirmation of endotracheal tube placement, the diagnosis of hip effusions, the identification of landmarks during lumbar puncture, procedural guidance during peripheral nerve blocks, and the diagnosis of skull fractures. Many of these applications have not been rigorously studied in pediatric patients; however, this article offers a summary of the latest applications of this diagnostic tool in emergency care.
(RbxK1-x)3C60 Superconductors: Formation of a Continuous Series of Solid Solutions.

By means of an approach that employs alkali-metal alloys, bulk single-phase (Rb x K 1– x ) 3 C 6O superconductors have been prepared for all x between 0 and 1. For x = 1 it is shown that the maximum superconducting fraction, which approaches 100% in sintered pellets, occurs at a Rb to C 60 ratio of 3:1. More importantly, single-phase superconductors are formed at all intermediate values of x , and it is shown that the transition temperature ( T c ) increases linearly with x in this series of materials. The formation of a continuous range of solid solutions demonstrates that the rubidium- and potassium-doped C 60 superconducting phases must be isostructural, and furthermore, suggests that the linear increase in T c with x results from a chemical pressure effect.
The role of atropine as a mediator blocker of induced bronchial obstruction.

Abstract Airway obstruction can be induced easily in asthmatic subjects by inhalations of specific allergenic extracts or solutions of cholinergic drugs. Atropine was administered to 26 inpatients with asthma of allergic origin by different routes and at different times prior to such challenge. Atropine did block the airway responses to Mecholyl under certain conditions, when given by inhalation but not by the sublingual route. When given by inhalation or by the intravenous route in the dose of 0.5 mg., or even in a dose as high as 1.5 mg., atropine failed to block the antigenic responses in 12 of 20 patients. Atropine mixed with histamine solution, in a dose of up to 1.6 to 2 mg. of histamine base, and given by inhalation failed to reduce the airway response to histamine in 18 of 19 patients. Atropine by inhalation was far less successful than Benadryl by the same route in interfering with allergen inhalation challenge. These observations suggest that the mechanism of the production of airway obstruction due to antigen-antibody interaction is not, in a majority of the patients studied, via the cholinergic pathway. Further, the importance of local action of drugs in the bronchial tree is re-emphasized.
The role of testimony in young children's solution of a gravity-driven invisible displacement task

Abstract Previous research has shown that young children make a perseverative, gravity-oriented, error when asked to predict the final location of a ball dropped down an S-shaped opaque tube ( Hood, 1995 ). We asked if providing children with verbal information concerning the role that the tubes play, in determining the ball's trajectory would improve their performance. Experiment 1 showed that performance of 3.5-year-olds improved after hearing testimony about the movement of the ball. Experiment 2 showed that the specific content of the testimony – rather than any accompanying non-verbal cues – helped children improve. These findings suggest that other people's testimony can be a valuable source of information when young children learn about the physical world. Indeed, under some circumstances children seem to benefit more from verbal than visual information. An educational implication is that it may sometimes be ineffective to focus on the impact of first-hand experience while marginalizing the role of verbal information.
Theoretical investigations of the light-induced effects in hydrogenated amorphous silicon

Abstract The light-induced effects in hydrogenated amorphous silicon (a-Si:H) are briefly described, and the two classes of models for their origin are summarized. A wide array of recent theoretical calculations that have been performed to elucidate the microscopic and macroscopic mechanisms for light-induced changes are described in detail. Although the basic origins of the effects are still in doubt and may be quite complex, there is at present a great deal of theoretical and experimental evidence in favor of the existence of large concentrations of charged centers in all a-Si:H samples.
Whimpers and bangs: of death and dying in the nervous system.

Mechanisms of cell death in general and in the nervous system in particular have received increasing attention over the past several years. Recent studies have begun to address the pathogenetic and...
Mouse glycosylphosphatidylinositol-specific phospholipase D (Gpld1) characterization.

Glycosylphosphatidylinositol-specific phospholipase D (GPI-PLD) is an 110-kDa monomeric protein found in the circulation that is capable of degrading the GPI anchor utilized by dozens of cell-surface proteins in the presence of detergent. This protein is relatively abundant (5–10 μg/ml in human serum), yet its sites of synthesis, gene structure, and overall function are unclear. It is our purpose to use the mouse system to determine its putative roles in lipid transport, pathogen control, and diabetes. We have isolated murine full-length cDNA for GPI-PLD from a pancreatic alpha cell library. The deduced amino acid sequence shows 74% homology to bovine and human GPI-PLD. There is a single structural gene (Gpld1) mapping to mouse Chromosome (Chr) 13, and among nine tissues, liver showed the greatest abundance of GPI-PLD mRNA. Genetic differences in serum GPI-PLD activity were seen among four mouse strains, and no correlation was seen between GPI-PLD activity and circulating levels of high density lipoproteins in these mice. This is the first report of map position and genetic regulation for Gpld1. This information will enable us to further study the expression and function of GPI-PLD in normal and pathological conditions.
Production and characterization of monoclonal antibodies to rat liver microsomal 3-hydroxy-3-methylglutaryl-coenzyme A reductase

Abstract Rat liver microsomal 3-hydroxy-3-methylglutaryl-CoA reductase [HMG-CoA reductase; mevalonate:NADP+ oxidoreductase (CoA-acylating), EC 1.1.1.34], the key regulatory enzyme in cholesterol biosynthesis, has been purified to apparent homogeneity. Purified HMG-CoA reductase yields a single diffuse band when NaDodSO4/polyacrylamide gels are stained with Coomassie blue and yields two adjacent bands when gels are stained with silver. Purified reductase was used to elicit the production of monoclonal antibodies. Spleen cells from BALB/c mice immunized with purified HMG-CoA reductase were fused with Sp-2/0 myeloma cells. Clones producing monoclonal antibodies to HMG-CoA reductase were identified by using a solid-phase radioimmunoassay and were subcloned in soft agar. The three relatively stable hybridoma lines isolated secrete different Igs as judged by their antibody subclasses and differing abilities to inhibit HMG-CoA reductase in solution. Efficient precipitation of solubilized HMG-CoA reductase was achieved with the two IgG antibodies but not with the IgM. A mixture of all three monoclonal antibodies immunoprecipitates more than 90% of the HMG-CoA reductase activity in solubilized rat liver extracts. These monoclonal antibodies should be useful probes for investigation of the regulation of HMG-CoA reductase and cholesterol synthesis.
Why tunneling FETs don't work, and how to fix it

To date, TFET results have been unsatisfying. The best reported subthreshold swings have been measured at a current density of around a nA/um and get significantly worse as the current increases. In order to achieve a better performance, there are fundamental design issues that need to be engineered. We can understand these issues by analyzing the three types of devices shown in Fig 1. The voltage required to operate a TFET can be given by: VDD = VSS × Log(Ion /Ioff)+ VOV. VSS is the subthreshold swing and VOV is the overdrive voltage needed to achieve the desired on-current after threshold. VOV will be determined by the device geometry as shown in Fig 2 [1]. Introducing quantum confinement in the direction of tunneling increases the conductance by 1-2 orders of magnitude at low voltage. VSS is given by the following model [2]: SS = 1/ ηel × (1/SBarrier + ηconf/SDOS)-1 (1) ηel is the electrostatic gate efficiency. ηconf is the quantum confinement efficiency and comes from energy level shifts that occur when the quantum well shape changes with bias. SBarrier represents the steepness in mV/decade that comes from changing the thickness of the tunneling barrier. SDOS is the steepness of the joint density of states (DOS) and represents the rate at which the joint DOS fall off as the band edges are misaligned.