cssi/SciSciGPT-SciSciNet huggingface dataset:
Expectation maximization approach to vessel enhancement in thoracic CT scans

Vessel enhancement in volumetric data is a necessary prerequisite in various medical imaging applications. In the context of automated lung nodule detection in thoracic CT scans, segmented blood vessels can be used to resolve local ambiguities based on global considerations and so improve the performance of lung nodule detection algorithms. Segmenting the data correctly is a difficult problem with direct consequences for subsequent processing steps. Voxels belonging to vessels and nodules in thoracic CT scans are both characterized by high contrast with respect to a local neighborhood. Thus in order to enhance vessels while suppressing nodules, additional characteristics should be used. In this paper we propose a novel vessel enhancement filter that is capable of enhancing vessels and junctions in thoracic CT scans while suppressing nodules. The proposed filters are based on a Gaussian mixture model which is optimized through expectation maximization. The proposed filters are based on first order differential quantities and so are less sensitive to noise compared with known Hessian-based vessel enhancement filters. Moreover, the proposed filters utilize an adaptive window and so avoid the common need for multiple scale analysis. The proposed filters are evaluated and compared to known techniques qualitatively and quantitatively on both synthetic and actual clinical data and it is shown that the proposed filters perform better.
Termination of a randomized controlled trial of two vasectomy techniques

Family Health International (FHI) and EngenderHealth conducted a multicenter, randomized controlled trial to evaluate a fascial interposition (FI) component of a vas occlusion procedure for male sterilization. A data monitoring committee (DMC) was established to provide independent review of the interim report. The DMC met to review the interim report after enrollment of 552 men. As planned, an estimate of the hazard ratio (HR) for successful vasectomy for the FI group versus the no-FI group controlling for age of the participant and level of experience of the surgeon was obtained for the interim report using Cox's proportional hazards regression. The main analysis comparing time to vasectomy success, defined as two consecutive azoospermic semen samples, was highly significant and met the prespecified level for stopping enrollment (HR=1.54, p<0.01). However, a troublesome age by vasectomy technique interaction became apparent in the analysis. FI was clearly beneficial for younger males. However, the trend for older men was not as clear. The DMC recommended continuing the trial to better study this interaction and obtain more data to clarify the effect of FI for older men. After consulting further with the DMC, the study statisticians presented the interim report to senior management at FHI. A meeting between FHI senior management and the DMC followed. After much deliberation, trial enrollment was terminated. Follow-up of participants already enrolled in the study continued as planned. This paper presents the issues involved in the decision to terminate the study.
Characterization of the excitable gap in a functionally determined reentrant circuit. Studies in the sterile pericarditis model of atrial flutter.

BACKGROUNDSingle premature beats were introduced in the reentrant circuit during stable atrial flutter in the canine sterile pericarditis model to test the hypotheses that (1) despite the fact that the reentrant circuit is functionally determined, there is a fully excitable gap; (2) the excitable gap in the reentrant circuit is not uniform; and (3) inhomogeneities of conduction in the reentrant circuit explain the effects of premature beats.METHODS AND RESULTSA multiplexing system was used to record 190 unipolar electrograms from the right atrial free wall during 18 atrial flutter episodes in 9 dogs. In all 18 episodes, premature stimuli captured the atrial flutter reentrant circuit. At the longest coupling intervals, the return cycle at the site closest to the pacing site did not prolong. As the coupling interval of the premature stimulus decreased, the return cycle then progressively increased, associated with changes in conduction in the reentrant circuit that were not uniform. The result was that coup...
Accumulation and Retention of Dietary 14 C-DDT by Atlantic Menhaden

Abstract The accumulation and retention of dietary 14C-DDT by young-of-the-year menhaden, and the effect of 14C-DDT exposure on growth of menhaden were studied. A simple mathematical model was developed to predict DDT flux in a natural menhaden population. Uptake of 14C-DDT was dose dependent and a function of exposure time. Prediction equations summarize the 14C-DDT uptake by menhaden for each of three exposure levels. Menhaden assimilated and retained 17 to 27 percent of the cumulative dosages of 14C-DDT. The biological half-life of 14C-DDT in menhaden was estimated to be 428, 64, and 137 days, respectively, for the low (0.58 ppb), medium (9.0 ppb), and high (93 ppb) dose groups. Exposure to dietary 14C-DDT at these concentrations did not produce any effect on growth of menhaden nor did starvation significantly affect their retention of 14C-DDT. The linear DDT flux model for menhaden was: FDta = (γ + λ) (Dm), where F is the daily feeding rate, Df is the DDT concentration in the food, a is the fraction o...
Hormonal Regulation of MicroRNA Expression in Steroid Producing Cells of the Ovary, Testis and Adrenal Gland

Background Given the emerging roles of miRNAs as potential posttranscriptional/posttranslational regulators of the steroidogenic process in adrenocortical and gonadal cells, we sought to determine miRNA profiles in rat adrenals from animals treated with vehicle, ACTH, 17α-E2 or dexamethasone. Key observations were also confirmed using hormone (Bt2cAMP)-treated mouse Leydig tumor cells, MLTC-1, and primary rat ovarian granulosa cells. Methodology RNA was extracted from rat adrenal glands and miRNA profiles were established using microarray and confirmed with qRT-PCR. The expression of some of the hormone-sensitive miRNAs was quantified in MLTC-1 and granulosa cells after stimulation with Bt2cAMP. Targets of hormonally altered miRNAs were explored by qRT-PCR and Western blotting in adrenals and granulosa cells. Results Adrenals from ACTH, 17α-E2 and dexamethasone treated rats exhibited miRNA profiles distinct from control animals. ACTH up-regulated the expression of miRNA-212, miRNA-182, miRNA-183, miRNA-132, and miRNA-96 and down-regulated the levels of miRNA-466b, miRNA-214, miRNA-503, and miRNA-27a. The levels of miR-212, miRNA-183, miRNA-182, miRNA-132, miRNA-370, miRNA-377, and miRNA-96 were up-regulated, whereas miR-125b, miRNA-200b, miR-122, miRNA-466b, miR-138, miRNA-214, miRNA-503 and miRNA27a were down-regulated in response to 17α-E2 treatment. Dexamethasone treatment decreased miRNA-200b, miR-122, miR-19a, miRNA-466b and miRNA27a levels, but increased miRNA-183 levels. Several adrenal miRNAs are subject to regulation by more than one hormone. Significant cAMP-induced changes in certain miRNAs were also noted in MLTC-1 and granulosa cells. Some of the hormone-induced miRNAs in steroidogenic cells were predicted to target proteins involved in lipid metabolism/steroidogenesis. We also obtained evidence that miR-132 and miRNA-214 inhibit the expression of SREBP-1c and LDLR, respectively. Conclusion Our results demonstrate that expression of a number of miRNAs in steroidogenic cells of the testis, ovary and adrenal glands is subject to hormonal regulation and that miRNAs and their regulation by specific hormones are likely to play a key role in posttranscriptional/posttranslational regulation of steroidogenesis.
Squared eigenfunctions and linear stability properties of closed vortex filaments

We develop a general framework for studying the linear stability of closed solutions of the vortex filament equation (VFE), based on the correspondence between the VFE and the nonlinear Schrodinger (NLS) equation provided by the Hasimoto map, and on the construction of solutions of the linearized equations in terms of NLS squared eigenfunctions. In particular, we show that the differential of the Hasimoto map is a one-to-one correspondence between curve variations and perturbations of NLS potentials induced by squared eigenfunctions. We apply this framework to vortex filaments associated with periodic finite-gap NLS potentials in the genus one case, and for cnoidal potentials we characterize the stability of the associated filaments in terms of their knot type.
Critical nanofabrication parameters for the e-beam assisted design of a subwavelength aluminum mesh

Using finite difference time domain simulations and e-beam assisted lithography we designed and fabricated high transmission transparent contacts for UV nitride devices which consist in perpendicular sets of parallel aluminum lines with a period as low as 260 nm. Transmittance values as high as 100% were predicted for aluminum meshes with the optimized periods, metal line widths and thicknesses. Simulations were compared with optical transmittance measurements. The critical parameters -such as grain size, edge roughness and mesh coating- were determined. The large aluminum grain was decreased by performing a cold aluminum deposition. The aluminum oxide layer over the aluminum mesh was found to reduce the mesh transmittance. Several alternatives were studied to overcome this issue such as coating the mesh with a thin gold or silicon dioxide layer. While the second option appeared promising the addition of the gold layer required much more improvement.
Aerosol bronchodilator delivery methods. Relative impact on pulmonary function and cost of respiratory care.

• Thirty-six acutely ill, hospitalized patients with acute exacerbations of obstructive airway disease and a greater than 10% increase in forced expiratory volume in 1 s after administration of aerosolized bronchodilator were randomized to receive either metaproterenol sulfate delivered by updraft-compressor nebulization (UDN) or terbutaline sulfate delivered by metered-dose inhaler (MDI) with a spacer. Serial analyses of pulmonary function measurements were performed with the use of 95% confidence intervals for the percentage response ratios of MDI to UDN. The response to MDI was at least equivalent to that of UDN, and MDI use was associated with no prolongation of hospital stay. Equivalent bronchodilation was achieved with MDI therapy with a lower daily charge for therapy for each patient and less respiratory therapist time. In hospitalized bronchodilator-responsive patients with acute exacerbations of obstructive airway disease, the MDI/spacer combination is the preferred approach when the status of the patient allows its use. (Arch Intern Med1989;149:618-623)
Surgical skills acquisition: performance of students trained in a rural longitudinal integrated clerkship and those from a traditional block clerkship on a standardized examination using simulated patients

Abstract Objectives Rural longitudinal integrated clerkship (LIC) programs for third-year medical students provide strong educational curricula and can nurture interest in rural surgical practice. Students learn technical skills in an apprenticeship model. Variability in instruction and patient experiences across sites, coupled with a lack of simulation facilities, raise some concerns about technical skill development. To explore the adequacy of skills acquisition for students in the University of Minnesota Rural Physician Associate Program (RPAP), this study compared RPAP students’ performance on a scenario-based Objective Structured Assessment of Technical Skills (OSATS) with that of traditional surgery block clerkship students (Course 7500). Design, Setting, and Participants This is a nonexperimental post-only study. All enrolled students ( n = 254) completed the OSATS examination. Students in the Course 7500 ( n = 222) completed 15 hours of simulation skills training and supervised practice during their 6-week clerkship. RPAP students ( n = 32) completed 3 hours of skills training before their 9-month rural assignment. Both groups had access to comprehensive online materials. Mean OSATS checklist, global rating, and total scores were compared at the end of training using t tests (p Results Both groups did well on the OSATS. There were no statistical differences in completion time, checklist scores, mean global ratings, or total scores. RPAP students reported significantly more days in the OR, surgery cases, and first assists. Experience with OSATS tasks reported by RPAP students during clinical rotations correlated with their OSATS performance. Conclusion This study supports the viability of the LIC model for fundamental skills acquisition when augmented with introductory simulation skills training and online resources. It also suggests that simulation fills a training gap for students in a traditional surgery block clerkship program. It opens a dialog about the potential partnership of surgery departments with rural LICs to address rural general surgery shortages. Further research in this aspect is needed.
Impact of stress and stress physiology during pregnancy on child metabolic function and obesity risk.

Purpose of reviewTo summarize recent conceptual frameworks and empirical findings addressing the role of prenatal stress and stress biology in the context of fetal programming of metabolic function and obesity risk.Recent findingsThe link between stress exposure and adverse health outcomes is well e
Three-dimensional lithography cases for exploring technology solutions and benchmarking simulators

Advances in lithography simulation have made three dimensional analysis practical. This has resulted in a need for test structures. Five test structures of increasing topological complexity are proposed and are specified mathematically. The first two have been examined with the SAMPLE-3-D simulator. The first example is a two dimensional Gaussian etch rate extended into the third dimension. The second example is the analysis of side lobe formation in phase shifted masks. Because it is necessary to minimize the effect of the side lobes on resist development, adjusting for the proper resist parameters to accomplish this is important. Third is the formation of standing waves. The proper numerical analysis of the evolution of this structure is difficult for surface based simulators, and therefore important for testing. Fourth, holes in the resist via reflective notching is an effect that is of great importance to technologists and is a difficult problem for simulators due to the formation of holes and tunnels. Fifth is the development of a phase shifted contact cut with significant sidelobes and standing waves. This combines the simulation difficulties encountered in examples two and three, and creates new horn shaped structures to form a particularly difficult geometry problem. The mathematical models for each structure are also listed, and a discussion of the SAMPLE-3-D simulator is included.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Synthesis of Indium Oxide Microspheres for Antistatic Spacecraft Coatings

Indium oxide microspheres were synthesized for potential use in novel, polymer-based antistatic coatings for exposed spacecraft surfaces. Non-agglomerating indium oxide microspheres with diameters ranging from 0.5–2.0 μm were produced using an aerosol spray pyrolysis technique. The precursor solution used to generate the aerosol droplets for pyrolysis consisted of indium acetate dissolved in water; however, the actual indium species present in solution was identified as the hydrolysis product, dihydroxy(acetato)indium. Thermogravimetric analyses of commercial indium acetate and of pure crystals of the dihydroxy(acetato)indium compound both demonstrated clean solid-state pyrolyses to generate pure indium oxide, as confirmed by x-ray diffraction and infrared spectroscopic analysis. Air was used as the carrier gas for the aerosol droplets for the spray pyrolysis experiments, and pyrolysis took place within a 2′′ tube furnace. The microspheres were characterized by x-ray diffraction and scanning electron microscopy. The non-agglomerating characteristics of the microspheres, combined with their small size, indicates that these particles are highly promising for dispersion within a polymer matrixes required for novel polymer-based antistatic films.
The Effect of Pencil Size and Shape on the Pre-Writing Skills of Kindergartners

This study examined the effect of pencil size and shape on the pre-writing skills of children in kindergarten. A sample of 126 kindergartners from a city school in the Midwest participated in the study. The Graphmotor Task Instrument was used in an adapted format to test the children's pre-writing skills while using a triangular shaped pencil, a standard pencil, and a large diameter pencil. The results of the study indicated no effect of pencil size or shape on the quality of the children's writing. Further research is recommended to determine if the adapted writing tools, which are recommended by many teachers and occupational therapists, do improve the handwriting of children with handwriting deficits.
Drop-on-Demand: A Scale Analysis

An increasing number of applications deal with dispensing of micro-droplets. For several years the fluids used were mostly Newtonian with low viscosity but there is nowadays a tendency to use more complex fluids. Some recent applications are encountered in the pharmaceutical industry where there is a need of producing on-demand identical droplets of a given size that can be used for drug delivery and in bioengineering where droplets have to contain cells used for tissue manufacturing or organ printing. The objective of the paper is to show that scale analysis is an efficient tool to classify the physical phenomena contributing to the breakup of a jet or of a liquid filament of a complex fluid and to provide guidelines for controlling the droplet formation process.Copyright © 2013 by ASME
Medical management of small preterm infants with symptomatic patient ductus arteriosus

During 1975, 38 of 44 infants with a birth weight of ≤1,500 gm who developed pulmonary edema and congestive heart failure due to a patent ductus arteriosus were managed medically until the ductus closed spontaneously days or weeks later. Overall survival was 71%, and there were no deaths among 11 infants weighing more than 1,250 gm. Pulmonary complications were prevalent and were attributed to the extensive use of mechanical ventilation required to control pulmonary edema. The results of this study document the results to be expected when small preterm infants with a symptomatic patent ductus arteriosus are managed without surgical or pharmacologic intervention and provide a basis for the rational design of clinical trials evaluating other management approaches.
Differential Polarized Reflectance Spectroscopy at Air/Water and Air/Metal Interfaces

We report the direct measurement of differential polarized reflectance spectra for samples at air/water and air/metal interfaces. The central component for these measurements is a polarization-division interferometer (PDI). This interferometer uses an in-house-designed beamsplitter constructed in-house from a BaF2 polarizer and a matching substrate. In conjunction with a linear polarizer in front of the source and two rooftop mirrors, one in each arm of the interferometer, the PDI divides the input beam into two orthogonal linear polarization components, recombines them for interference at the beamsplitter, and directs the output beam at 90° to the direction of the input beam. Collimated light rays exiting the interferometer are focused by an f/5 lens and bent from the horizontal propagating axis by a ZnSe wedge to give an angle of incidence of ~75°, at the sample. The reflected rays are brought back to the horizontal propagation direction by another ZnSe wedge and focused onto the detector by an f/1 lens. The interferogram obtained in this manner represents the differential polarized reflectance interferogram whose cosine Fourier transform directly gives the differential polarized reflectance spectrum. Thus, these spectra were obtained without need for the commonly used photoelastic modulator. Representative spectra for monolayers on a water surface and for samples on a gold surface are presented.
Materials aging at the mesoscale: Kinetics of thermal, stress, radiation activations

Abstract The complexity of materials aging may be seen as a result of the interplay between several activation processes operating on multiple spatial and temporal scales. Though the disciplines involved may seem disparate at first, material aging fundamentally could be linked by the same set of underlying activations and responses of the system. We examine how recent studies of shear-induced deformation and rheological flow initiated in the soft-matter community can be leveraged to probe the mechanisms of radiation damage in nuclear materials. Bridging these two traditionally separate areas of research demonstrates the emerging notions of mesoscale science as a research frontier concerned with linking macroscale behavior to microscale processes in driven systems. We suggest the combining of microstructure-sensitive measurements with fundamental theories and mechanism-specific simulations is essential to addressing metastable materials responses of strongly activated states.
Imaging of complications from hematopoietic stem cell transplant

Stem cell transplant has been the focus of clinical research for a long time given its potential to treat several incurable diseases like hematological malignancies, diabetes mellitus, and neuro-degenerative disorders like Parkinson disease. Hematopoietic stem cell transplantation (HSCT) is the oldest and most widely used technique of stem cell transplant. HSCT has not only been used to treat hematological disorders including hematological malignancies, but has also been found useful in treamtent of genetic, immunological, and solid tumors like neuroblastoma, lymphoma, and germ cell tumors. In spite of the rapid advances in stem cell technology, success rate with this technique has not been universal and many complications have also been seen with this form of therapy. The key to a successful HSCT therapy lies in early diagnosis and effective management of complications associated with this treatment. Our article aims to review the role of imaging in diagnosis and management of stem cell transplant complications associated with HSCT.
Radioiodine metabolism in children and adults after the ingestion of very small doses.

One day after oral ingestion of very small doses (about 0.01 microcurie) of an I 131 /I 135 mixture, the radioiodine content of the thyroid gland was similar in children and adults (about 20 percent of the dose ingested) as was the biological half-life of the iodine (about 90 days). Measurements were made in 15 minutes by means of a whole-body counter with a cylindrical sodium iodide (Tl) crystal, 20 cm in diameter and 10 cm thick.
Takotsubo cardiomyopathy associated with syncope

We report an 81-year-old Japanese patient with takotsubo cardiomyopathy associated with syncope with the possibility that the latter event evoked the former condition. Initial investigations revealed elevation of cardiac enzymes and electrocardiography changes consistent with acute myocardial infarction. The patient subsequently underwent cardiac catheterization that revealed left ventricular apical ballooning and decreased left ventricular ejection fraction without significant coronary artery lesions. A marked elevation in plasma norepinephrine, as a result of baroreflex unloading associated with profound hypotension or frank baroreflex failure, may well have caused takotsubo cardiomyopathy.
Prevalence of Hyponatremia and Association with Mortality: Results from NHANES

Abstract Background Hyponatremia is the most common electrolyte abnormality in hospitalized patients and is associated with adverse outcomes, but its prevalence and significance in the general US population is unknown. Our aims were to determine the prevalence of hyponatremia and its association with mortality in the population. Methods We performed a population-based, cross-sectional study of 14,697 adults aged ≥18 years who participated in the nationally representative National Health and Nutrition Examination Survey for 1999-2004. By using measurements of serum sodium corrected for dilutional effect of hyperglycemia, we determined the association of hyponatremia with patient characteristics, comorbidities, and prescription medications, and performed unadjusted and adjusted Cox proportional hazards regression to find the association of hyponatremia with all-cause mortality. Results We provide the first estimate of the prevalence of hyponatremia in the US population, which in our weighted analysis was 1.72%. Prevalence of hyponatremia was significantly higher in women (2.09%, P = .004) and increased with age. Hyponatremia was more common in subjects with hypertension, diabetes, coronary artery disease, stroke, chronic obstructive pulmonary disease, cancer, and psychiatric disorders, and less common in those with no comorbidities (1.04%, P P P Conclusions Our findings suggest that hyponatremia is a predictor of mortality in the general population independently of age, gender, and comorbid conditions.
Application of multiple objective optimization techniques to finite element model tuning

This report examines tuning a finite element model using vector optimization techniques. Structural models using finite element theory often need to be adjusted so they can accurately simulate the real structure. The goal is to tune the model such that it will reproduce data derived from structural tests. First, the performance indices are extremized using multiple objective optimization theory, producing a set of possible solutions. Next, the solutions are rank ordered according to a decision maker's preferences to select the best answer. The tuning process was applied to a T-38 horizontal stabilizer. Numerous weighted solutions contained a best static deformation model, a best frequency model and three intermediate combinations of these two models. This automated procedure proved to be a versatile method capable of producing solutions for many types of tuning problems.
Women Police in a Traditional Society: Test of a Western Model of Integration

It has been argued that policewomen in traditional societies do not aspire to being fully integrated into mainstream policing, but may prefer a more restricted and segregated role. This thesis is examined in the context of policing in Tamil Nadu, a state of India. The present study uses data gathered through interviews and a standardized questionnaire, and focuses on the preferences expressed by women officers about roles and styles of policing. These preferences are compared with those of women interviewed in earlier research in India and other countries. It is concluded that, while progress to full integration in traditional societies may be slower, it seems to follow the same sequence of stages found in Western societies.
Spline-based sieve maximum likelihood estimation in the partly linear model under monotonicity constraints

We study a spline-based likelihood method for the partly linear model with monotonicity constraints. We use monotone B-splines to approximate the monotone nonparametric function and apply the generalized Rosen algorithm to compute the estimators jointly. We show that the spline estimator of the nonparametric component achieves the possible optimal rate of convergence under the smooth assumption and that the estimator of the regression parameter is asymptotically normal and efficient. Moreover, a spline-based semiparametric likelihood ratio test is established to make inference of the regression parameter. Also an observed profile information method to consistently estimate the standard error of the spline estimator of the regression parameter is proposed. A simulation study is conducted to evaluate the finite sample performance of the proposed method. The method is illustrated by an air pollution study.
Stem Cells: It's Good to Have Choices

Three types of stem cells, embryonic, adult, and induced pluripotent stem cells, are currently studied by scientists. Barack Obama's presidency has opened the door for stem cell research by revoking statements and orders made during the former President Bush's administration. This provisional period will allow the National Institute of Health to rewrite policies governing how federal funds are distributed for stem cell research. These new regulations will grant more freedom to researchers wishing to use stem cells in their research and challenge them to determine the most appropriate stem cell treatment for a given disorder.
Technical Note-On the Weighted Selection Algorithm for Certain Linear Programs with Nested Constraint Coefficients

Recently, B. Faaland has developed a weighted selection algorithm for certain linear programming problems with nested constraint coefficients. The purpose of this note is to present a direct, concise proof of validity of Faaland's weighted selection algorithm that does not use graph theory or duality theory.
Substituent Effects in the Vinylcyclopropane Radical Cation Rearrangement: A Computational Road to a New Synthetic Tool

The effect of substituents on the rearrangement of vinylcyclopropane radical cation to cyclopentene was explored by density functional theory. Correlations have been established between the activation energy of the system and the nature, as well as the position, of the substituents. It was found that radical- or cation-stabilizing substituents in select positions reduce the activation energy for the rearrangement substantially, while activation energies for competing hydrogen shifts were largely left unchanged. We have identified positions in the vinylcyclopropane where substitution is necessary, and others that can be substituted less discriminately. The mechanism of the rearrangement changes from stepwise to concerted when a strongly cation-stabilizing substituent is used, because the first step in the stepwise reaction becomes a barrierless ring opening of a strained cyclopropane. Steric effects were also explored and have been found to be of crucial importance for the success of a rearrangement. Finally, a simple set of rules has been devised to predict the outcome of oxidation of a vinylcyclopropane without requiring detailed mechanistic investigations. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Noninvasive recovery of acinar anatomic information from CO2 expirograms

A numerical single path model of respiratory gas exchange with distributed alveolar gas sources was used to estimate the anatomical changes in small peripheral airways such as occur in chronic obstructive pulmonary diseases (COPD). A previous sensitivity analysis of the single path model showed that decreasing total acinar airway cross-sectional area by an area reduction factor, R, results in computed gas expirograms with Phase III steepening similar to that observed in COPD patients. From experimental steady state CO2 washout data recorded from six healthy subjects and six COPD patients, optimized area reduction factors for the single path model were found that characterize peripheral airway anatomy for each subject. Area reduction factors were then combined with measured functional residual capacity data to calculate the normalized peripheral airspace diameters in a given subject, relative to the airspace diameters in the generations of an idealized standard lung. Mean area reduction factors for the patient subgroup were 63% of those for the healthy subgroup, which is related to the gas transport limitation observed in disease. Mean airspace sizes for the patient subgroup were 235% of the healthy subgroup, which characterizes the increase in size and reduction in number of peripheral airspaces due to tissue erosion in emphysema. From these results, the air-phase diffusive conductance in COPD patients was calculated to be 32% of the mean value in the healthy subjects. These findings correlated well with standard pulmonary function test data for the patients and yield the recovery of acinar airway information from gas washout by combining the single path model with experimental measurements.
Mechanisms of c-myc-mediated transcriptional repression of growth arrest genes

Constitutive expression of the proto-oncogene c-myc results in oncogenic activation and contributes to progression of a wide range of human and animal tumors. Myc executes its multiple activities mostly through transcriptional regulation of the target genes. The special interest of this review is the mechanism of transcriptional repression of cell cycle inhibitors by Myc. Myc suppresses expression of cell cycle/growth arrest genes gas1, p15, p21, p27, and gadd34, -45, and -153. It appears that Myc represses growth arrest gene transcription by at least two distinct mechanisms. One mechanism is limited to the binding of Myc-Max heterodimers to the Inr element in their promoters and inhibition of Miz-1 or other transcriptional activators via the C-terminal domain of c-Myc. This mechanism requires DNA binding of the Myc-Max complex to Inr sequences. The other mechanism is dependent on c-Myc binding to the Sp1 transcription factor via the c-Myc central region and inhibition of Sp1 transcriptional activity. At this time it is not entirely clear which Sp1-containing promoters will be repressed by c-Myc and what other modes of c-Myc transcriptional repression may exist. The ability of c-Myc to repress transcription of growth arrest genes may contribute to its potential to promote proliferation and oncogenesis.
MANAGEMENT OF BRONCHOPULMONARY DYSPLASIA (BPD) USING PRESSURE SUPPORT VENTILATION. 1970

Recent technological advances in signal detection, transduction and processing have enabled the inclusion of pressure support ventilation (PSV) in mechanical ventilators designed for neonatal use. PSV is a ventilatory mode used in spontaneously breathing infants to provide an inspiratory pressure assist to overcome the work of breathing imposed by high resistive endotracheal tubes, the ventilator circuit, and the demand valve. It is pressure triggered, pressure limited, and flow cycled.
Experimental measurements of sidebranching in thermal dendrites under terrestrial-gravity and microgravity conditions

We perform sidebranch measurements on pure succinonitrile dendrites grown in both microgravity and terrestrial-gravity conditions for a set of supercoolings within the range 0.1--1.0 K. Two distinct types of sidebranch regions, uniform and coarsening, exist, and are characterized by the distance from the tip at which the region began, ${D}_{i},$ and the average spacing of sidebranches within that region, ${\ensuremath{\lambda}}_{i}.$ There does not appear to be any significant dependence on either gravity level or supercooling when ${D}_{i}$ or ${\ensuremath{\lambda}}_{i}$ are normalized with respect to the radius of curvature of the tip, R. The apparently constant normalized proportionality factor between ${D}_{i},$ ${\ensuremath{\lambda}}_{i},$ and R, regardless of the relative importance of diffusion and convective heat transport, demonstrates self-similarity between dendrites of different length scales propagating under various heat transfer conditions. However, when the form of the sidebranch envelope is defined by a power law relating the amplitude and relative positions of the sidebranches normalized to the radius of the tip, the form is seen to have significant variations with supercooling between the terrestrial gravity and microgravity growth dendrites. Furthermore, both the amplitude coefficient and exponent from the power-law regressions of the microgravity data are statistically different (95% confidence level) than their terrestrial counterparts.
Increased NMDA affinity of the H780Q mutant of the NMDA receptor

A point mutation within the coding sequence of the primary subunit of the N-methyl-d-aspartatge (NMDA) subtypr of glutamate receptor (glutamine substitution for histidine at position 780) exhibits a higher affinity for NMDA than the wild type receptor (EC50 5 versus 27 μM). To our knowledge this is the first point mutation of this ligand-gated ion channel described with higher agonist affinity. This observation may help further localize the agonist binding site and help to understand the heterogeneity of agonist affinity within the glutamate receptor family.
Angular momentum effects in nuclear evaporation processes: Charged-particle emission

Abstract The effect of angular momentum upon the evaporation of neutrons, protons and alpha particles from excited nuclei has been calculated from the statistical model. The level density assumed was of the Fermi gas type with a Gaussian J -dependence for values of J corresponding to a classical rotation energy less than the total excitation energy; it was assumed that there were no levels with J -values higher than this. Transmission coefficients for the emitted particles were computed from the optical model. Quantities computed as a function of the compound nucleus angular momentum included the average energy of the first emitted particle, the average change in angular momentum, the particle emission widths and the ratios of emission widths. The effect of angular momentum upon these quantities can be quite different for different nuclei at different excitation energies and for different choices of the parameters, especially the nuclear moment of inertia. When the classical rotational energy is considerably less than the excitation energy, these variations can be readily understood with the aid of approximate formulae derived from a very simple model. These formulae also give a rough guide as to the order of magnitude of the effects to be expected in any particular case. The results can be greatly altered when the compound nucleus spin is greater than the angular momentum of any available levels in the residual nucleus. Particle emission widths are sharply reduced, sometimes drastically, and the effect can be quite different particles, thus altering their emission ratios. Gamma de-excitation, which is not considered, will be important in some such cases.
Nanometer-scale heat-conductivity measurements on biological samples.

With semiconductor structures reaching the nanometer scale, heat conductivity measurements on the mesoscopic range of some tens of nanometers become an increasingly important aspect for the further improvement in digital processing and storage. Also the attempt to use atomic-force microscopy (AFM) technology for high-density data storage by writing information bits as nanometer-sized indentations into a polymer substrate with a heated cantilever tip asks for a careful investigation of the nano-scale heat-conductivity properties of polymers. Furthermore, in many AFM imaging applications, heat conductivity can provide additional information about the material the imaged structures consist of. In this respect, heat conductivity can also become very interesting in studies of usually quite heterogeneous biological samples, if the resolution can attain the nanometer range. In standard scanning thermal microscopy application, the tip forms a thermocouple, which precludes high-resolution imaging, as thermocouples cannot be made sufficiently small. In this paper, which focuses on biological applications, we demonstrate that by using an ultra sharp AFM cantilever with a Joule heating element above the tip structure different molecular components can be distinguished thanks to their different heat-conductivity properties. In this case, the resolution is determined by the actual tip size, and it can reach 10 nm.
Steric stability of alkoxy-precipitated TiO2 in alcohol solutions

Abstract An experimental program is described which evaluated the suitability of various surfactants as steric stabilizers for ethanol suspensions of alkoxy-precipitated TiO 2 particles. This experimental program included surfactant solubility, the effect of the polymer on the critical coagulation concentration of LiCl, and determination of the critical polymer concentration required to prevent coagulation. The results of these experiments allowed the selection of four surfactants from the twenty-seven evaluated which would sterically stabilize the particles against coagulation. In addition, hydroxypropyl cellulose allowed the precipitation to proceed in its presence. Adsorption during growth allowed for nearly complete protection from particle coalescence.
Potential Role of Caveolin-1 in Acetaminophen-Induced Hepatotoxicity

Caveolin-1 (Cav-1) is a membrane scaffolding protein, which functions to regulate intracellular compartmentalization of various signaling molecules. In the present studies, transgenic mice with a targeted disruption of the Cav-1 gene (Cav-1(-/-)) were used to assess the role of Cav-1 in acetaminophen-induced hepatotoxicity. Treatment of wild-type mice with acetaminophen (300 mg/kg) resulted in centrilobular hepatic necrosis and increases in serum transaminases. This was correlated with decreased expression of Cav-1 in the liver. Acetaminophen-induced hepatotoxicity was significantly attenuated in Cav-1(-/-) mice, an effect that was independent of acetaminophen metabolism. Acetaminophen administration resulted in increased hepatic expression of the oxidative stress marker, lipocalin 24p3, as well as hemeoxygenase-1, but decreased glutathione and superoxide dismutase-1; no differences were noted between the genotypes suggesting that reduced toxicity in Cav-1(-/-) mice is not due to alterations in antioxidant defense. In wild-type mice, acetaminophen increased mRNA expression of the pro-inflammatory cytokines, interleukin-1beta, and monocyte chemoattractant protein-1 (MCP-1), as well as cyclooxygenase-2, while 15-lipoxygenase (15-LOX), which generates anti-inflammatory lipoxins, decreased. Acetaminophen-induced changes in MCP-1 and 15-LOX expression were greater in Cav-1(-/-) mice. Although expression of tumor necrosis factor-alpha, a potent hepatocyte mitogen, was up-regulated in the liver of Cav-1(-/-) mice after acetaminophen, expression of proliferating cell nuclear antigen and survivin, markers of cellular proliferation, were delayed, which may reflect the reduced need for tissue repair. Taken together, these data demonstrate that Cav-1 plays a role in promoting inflammation and toxicity during the pathogenesis of acetaminophen-induced injury.
Elevated expression levels of ANXA11, integrins β3 and α3, and TNF-α contribute to a candidate proteomic signature in urine for kidney allograft rejection.

Purpose—Kidney transplantation is the treatment of choice for end stage renal disease, with long term allograft loss being the major obstacle, and for which potential treatments are based on a histological diagnosis. The problem is that markers for predicting graft rejection are limited in number and invasive and quite non-specific. We have hypothesized that protein biomarkers might be discovered in the urine of patients when acute or chronic rejection might be occurring. Experimental design—We have established a workflow in which initial screening for candidate biomarkers is first performed using urine samples on large scale antibody microarrays. This approach generated several dozen candidates. The next step is to qualify some of the strongest signals using the high throughput Reverse Capture Protein Microarray platform. Results—Four top candidates including ANXA11, Integrin α3 and Integrin β3, and TNFα initially identified by the antibody microarray platform were all qualified using Reverse Capture Protein Microarrays. We also used Receiver Operating Condition (ROC) curves to independently quantify the specificity and sensitivity of these four analytes. Conclusions and clinical relevance—The present data suggest that these novel four analytes in the urine, together or independently, may contribute to a robust and quantitative urine proteomic signature for diagnosing acute or chronic rejection of renal allografts.
Free-floating Iliofemoral Thrombus: A Risk of Pulmonary Embolism

• We retrospectively evaluated the risk of pulmonary embolism in hospitalized patients with venographically proved iliofemoral deep vein thrombosis (DVT). Venograms and clinical records of 78 patients with iliofemoral DVT were reviewed and the proximal intraluminal thrombus was characterized as free-floating (>5-cm nonadherent segment) or occlusive (no free-floating elements). The incidence of pulmonary embolism confirmed by high-probability radioisotope ventilation-perfusion lung scanning within ten days following venography was 9% (7/78) and was associated with 60% (3/5) free-floating and 5.5% (4/73) occlusive phlebographic criteria (P .05). Patients with iliofemoral DVT that met free-floating criteria are at significant risk for pulmonary embolism, despite the administration of heparin. (Arch Surg1985;120:806-808)
Narcissism and recollections of early life experiences

Recent studies have found associations between narcissistic personality features and retrospective accounts of early experiences. The current study sought to extend these previous findings by examining whether adaptive and maladaptive features of narcissism were associated with recollections of early life experiences in a non-clinical sample of undergraduate students (N = 334). Results revealed that the Entitlement/Exploitativeness feature of narcissism was associated with low security, high parental discipline, and high threats of separation. Narcissistic Grandiosity was positively associated with peer affectional support and parental discipline, whereas Narcissistic Vulnerability was not uniquely associated with memories of early life experiences. The results provide partial support for models of narcissism in which parents are recalled as failing to provide a secure base while inducing threats of separation and discipline. 2011 Elsevier Ltd. All rights reserved.
Microjet cooling devices for thermal management of electronics

This research is an effort to demonstrate the applicability of miniaturized synthetic jet (microjet) technology to the area of thermal management of microelectronic devices. Synthetic jets are jets which are formed from entrainment and expulsion of the fluid in which they are embedded. Design issues of microjet cooling devices are discussed along with characterization of excitation elements and the turbulent synthetic jets produced thereby. Geometrical parameters of the microjet cooling devices were empirically optimized with regards to cooling performance. The cooling performance of the optimized microjets was compared with previous theoretical and empirical studies of conventional jet impingement. The cooling performance of the microjet devices has been investigated in an open environment as well as in a vented and closed case environment. In such experiments, the synthetic jet impinges normal to the surface of a packaged thermal test die, comprising a heater and a diode-based temperature sensor. This test assembly allows simultaneous heat generation and temperature sensing of the package, thereby enabling assessment of the performance of the synthetic jet. Using microjet cooling devices, a thermal resistance of 30.1/spl deg/C/W has been achieved (when unforced cooling is used, thermal resistance is 59.6/spl deg/C/W) when the test chip is located at 15mm spacing from the jet exit plane. In order to more directly compare and scale the cooling results, a preliminary study on heat transfer correlations of the microjet cooling device has been performed. Finally, a comparison of the performance of the microjet cooler with standard cooling fans is given.