cssi/SciSciGPT-SciSciNet huggingface dataset:
Interphase boundary diffusion of oxygen and potassium in K-feldspar/quartz aggregates

Abstract Interphase boundary diffusion rates of oxygen and potassium in fine-grained K-feldspar/ quartz aggregates were determined experimentally at 450–700°C and 100 MPa (hydrothermal). The starting materials were hot-pressed and crystallized using equal weights of natural quartz fragments and orthoclase (KAlSi 3 O 8 ) composition glass. The technique employed isotopic tracers ( 18 O, 41 K) in an aqueous solution surrounding the sample, and depth profiling using an ion microprobe (SIMS). From the depth profiles, the product of the average boundary diffusion coefficient ( D ′) and average effective boundary width (δ) was calculated using numerical solutions to the appropriate diffusion equation. Potassium and oxygen profiles measured in the same samples are different, confirming a diffusional transport mechanism. Potassium diffusion in the K-feldspar/quartz aggregate has a greater activation energy than oxygen (218 vs. 75 kJ/mol), and the Arrhenius relations cross at ∼600°C. The D ′ δ values in the K-feldspar/quartz aggregates are about a factor of four greater than both oxygen and potassium D ′ δ values previously determined in monomineralic K-feldspar aggregates, and a factor of 20–40 greater than oxygen D ′ δ values in monomineralic quartz aggregates. The Arrhenius relations show the activation energies for both oxygen and potassium are similar for the K-feldspar/quartz and monomineralic K-feldspar aggregates, and significantly lower for oxygen in K-feldspar/quartz versus monomineralic quartz aggregates.
Transition From a Continuous to Discontinuous Understanding of Cardiac Conduction

This personal reflection that celebrates the 50th anniversary of Circulation Research focuses on an area of integrative electrophysiology—the extension of continuous medium theory to the discontinuous nature of cardiac propagation produced by the cellular interconnections (gap junctions). It is appropriate to note that as a clinician who shifted to the laboratory, my collaboration with Drs Roger Barr, J. Francis Heidlage, and Paul Dolber has provided me long-term training and checks on ideas that involve conduction theory, computer modeling, and cardiac architecture. That process has been particularly influenced by advances in this field that involve the measurement and mathematical modeling of ionic channel currents, as well as the immunohistological targeting of cardiac gap junction connexins. Although journal references are not used here, I have felt compelled to mention a few scientists who advanced selected ideas about the spread of currents in cardiac muscle. It is noteworthy that the widespread use of optical mapping to measure spiral waves that represent the behavior of cardiac wavefronts at a macroscopic size scale illustrates the contemporary importance of continuous medium theory. Interestingly, van Cappele first described complex spiral wave activity for cardiac muscle in 1980 by generating a computer model of a continuous isotropic sheet. Nine years passed before this phenomenon was experimentally confirmed in cardiac muscle. With spiral waves, the nonuniformities necessary to initiate the conduction disturbances that lead to reentry are induced experimentally as repolarization inhomogeneities (primarily by introducing stimuli at two different sites). Spiral waves are mentioned at the outset because the concept of spiral waves at a macroscopic level and the concept of discontinuous conduction at a microscopic level have both gained acceptance during the past two decades as paradigms for mechanisms of cardiac arrhythmias. Thus, it may be of interest to the reader to consider how experiments done in the …
Radiochemical Purity of [14C]-Proline: Implications for Measurement of Intracellular Collagen Degradation

Measurement of intracellular degradation of newly synthesized collagen requires use of radiochemically pure [14C]-proline. It is particularly important that levels of contaminating hydroxy-[14C]-proline or other radioactive species that migrate with hydroxyproline on cation-exchange resins be very low. The objective of this study was to determine how far the levels of these impurities could be reduced. Commercially available [14C]-proline was subjected to preparative ion-exchange chromatography. The procedure was capable of adequately separating authentic hydroxyproline from proline, however, upon rechromatography of the "purified" isotope on an analytic resin it was found that background radioactivity in the hydroxyproline region could not be reduced below approximately 500 parts per 10(6) parts of [14C]-proline. The contaminants appear to be generated during the procedure itself, suggesting that further efforts to purify the material would be unproductive. The background level can be a limiting factor in attempting to measure degradation in systems that synthesize very small amounts of collagen.
THE CAMBIUM AND SEASONAL DEVELOPMENT OF THE PHLOEM IN ROBINIA PSEUDOACACIA

The cambium in black locust consists of several layers of cells at all times. Cambial reactivation (division) is preceded by a decrease in density of cambial cell protoplasts and cell wall thickening but not by cell enlargement. During the resumption of cambial activity, periclinal divisions occur throughout the cambial zone. Early divisions contribute largely to the phloem side. The period of greatest cambial activity coincides with early wood formation. Judged by numerous collections made during two seasons (October, 1960-October, 1962) the seasonal cycle of phloem development is as follows. Phloem differentiation begins in early April, ends in late September. The amount of phloem produced is quite variable (range: 1-10 bands of sieve elements per year). Cessation of function begins with the accumulation of definitive callose in the first-formed sieve elements and spreads to those more recently formed. By late November all but the last-formed sieve elements are collapsed. All sieve elements are collapsed by mid-winter and before the resumption of new phloem production in spring. Phloem differentiation precedes xylem differentiation by at least 1 week, and apparently functional sieve elements are present 3 weeks before new functional vessel elements. Xylem and phloem production ends simultaneously in most trees.
The role of sentinel lymph node biopsy for melanoma.

Abstract Regional lymph nodes are a common site of melanoma metastases, and the presence or absence of melanoma in regional lymph nodes is the single most important prognostic factor for predicting survival. Furthermore, identification of metastatic melanoma in lymph nodes and excision of these nodes may enhance survival in a subgroup of patients whose melanoma has metastasized only to their regional lymph nodes and not to distant sites. Sentinel lymph node (SLN) biopsy was developed as a low morbidity technique to stage the lymphatic basin without the potential morbidity of lymphedema and nerve injury. The presence or absence of metastatic melanoma in the SLN accurately predicts the presence or absence of metastatic melanoma in that lymph node basin. When performed by experienced centers, the false-negative rate of SLN biopsy is very low. As such, the nodal basin that contains a negative SLN will usually be free of microscopic disease. Since occult micrometastatic disease affects only 12% to 15% of patients with melanoma, selective SLN dissection allows up to 85% of patients with melanoma to be spared a formal lymph node dissection, thus avoiding the complications usually associated with that procedure. While standard pathologic evaluation of lymph nodes may miss metastatic melanoma cells, more sensitive techniques are developing which may identify micrometastases more accurately. The clinical significance of these micrometastases remains unknown and is the subject of active investigations. Semin Oncol 29:341-352. Copyright 2002, Elsevier Science (USA). All rights reserved.
The Contribution of Experiential Avoidance and Social Cognitions in the Prediction of Social Anxiety

Background: Cognitive models propose that social anxiety arises from specific dysfunctional cognitions about the likelihood and severity of embarrassment. Relational frame theory (RFT), on the other hand, posits that social anxiety arises from the unwillingness to endure unpleasant internal experiences (i.e. experiential avoidance [EA]). Although cognitive models have garnered empirical support, it may be that newer models such as RFT can improve our ability to predict and treat social anxiety. Aims: We aimed to elucidate the relationship between dysfunctional cognitions and EA, as well as their independent and relative contributions to the prediction of social anxiety symptoms. We hypothesized that dysfunctional cognitions and EA would each be associated with social anxiety, as well as with each other. We also predicted that both EA and dysfunctional cognitions would remain independent predictors of social anxiety symptoms after controlling for each other and general distress. Method: Undergraduates high (n = 173) and low (n = 233) in social anxiety completed measures of social anxiety, dysfunctional cognitions, EA, and general distress. The overall sample was 66.3% female; mean age = 20.01 years (SD = 2.06). Results: Correlational analyses revealed that EA, dysfunctional cognitions, and social anxiety symptoms were moderately correlated with one another. Additionally, hierarchical regression analyses revealed that dysfunctional cognitions predicted social anxiety symptoms even after controlling for EA; the reverse was not found. Conclusions: Results suggest that EA and social anxiety specific cognitive distortions overlap to a moderate extent. EA does not add to the prediction of social anxiety symptoms above and beyond dysfunctional cognitions. Additional theoretical and treatment implications of the results are discussed.
174 MicroRNA EXPRESSION PROFILE IN BOVINE CUMULUS–OOCYTE COMPLEXES DURING LATE OOGENESIS

During late oogenesis, the mammalian oocyte synthesizes and stores mRNA necessary to guide the early stages of embryo development before the activation of embryonic transcription. The oocyte also contains many post-transcriptional regulatory mechanisms that coordinate mRNA stability and translation before specific activation. MicroRNAs (miRNAs) are short noncoding RNAs (17–25 nucleotides) that repress translation of target genes through sequence complementation and have recently been identified in murine oocytes. The objective of the current study was to identify and characterize the expression of miRNAs in bovine cumulus–oocyte complexes (COC) during late oogenesis as a potential mechanism for post-transcriptional regulation of mRNA in developing bovine oocytes. Ovaries from beef cattle (mixed populations) were obtained at a local abattoir. The COC were aspirated from 2- to 10-mm follicles and were pooled from each of 5 replicate collections for RNA extraction (n = 2241 total COC). Small RNA in the 16- to 27-bp range was isolated and used to construct cDNA libraries for sequencing, producing 2529 successful sequences that were clustered based on matching 14 consecutive bases to the most common member of the cluster. The consensus sequences of the clusters were screened for mitochondrial RNA, rRNA, tRNA, and snoRNA contaminants, leading to removal of 774 (31%) sequences from consideration. The remaining 1755 putative miRNA sequences were compared with known miRNA in miRBase, revealing 62 bovine COC miRNA clusters matching previously known sequences and 4 with no match. The cluster with the largest number of sequences identified in bovine COC matched the sequence of the let-7 miRNA family (657 sequences or 37% of putative miRNA). Within the let-7 family, let-7b (459 sequences or 26%) was the most abundant followed by let-7i (135 sequences or 8%). The four clusters that did not match sequences in miRBase represent putative novel miRNA. One of these four clusters had relatively high expression in bovine COCs (308 sequences or 18%), whereas the other 3 clusters had relatively low expression (total of 55 combined sequences or 3%). Expression of several putative miRNAs (let-7b, let-7i, miR-106a, and the abundant novel miRNA) in bovine COC were confirmed using TaqMan miRNA assays. These results demonstrate the presence of miRNA within bovine COC during late oogenesis, which suggests that these post-transcriptional regulatory elements may play a role in coordinating mRNA stability and translation in bovine oocytes.
Surface analysis of cubic silicon carbide (001)

Abstract Cubic β-SiC(001) surfaces were cleaned in ultra-high vacuum by heating within a Si atomic flux, allowing contaminant species to desorb while continuously replenishing volatile surface Si. Using this technique, surface compositions ranging from Si-rich to Si-deficient were prepared. Surfaces were subsequently characterized using Auger electron, electron energy loss. X-ray photoelectron, and ultraviolet photoelectron spectroscopies as well as low energy electron diffraction. Data are presented for a range of surface compositions which result in formation of several reconstructions: (3 × 1), c(4 × 2), (2 × 1), c(2 × 2), and (1 × 1). Results are interpreted based on surface models which include ordered arrays of surface Si dimers for Si-rich and Si-terminated surfaces and graphite formation for Si-deficient surfaces.
Some families of periodic solutions in the planarN-body problem

Recent results and existence proofs concerning periodic motions of circular-elliptic type forN=3 andN=4 are reviewed.
A Note on Two Dimensional Division Ring Extensions

A division subring Γ of a division ring Δ is said to be Galois in Δ (and Δ is Galois over Γ) if Γ is the set of invariants (or fixed points) of a group of automorphisms acting in Δ. The two dimensional Galois extensions of a division ring have been determined by Dieudonne.2 In this note we shall show that if Γ is a division ring of characteristic ≠ 2 which is finite dimensional over its center Ψ and Δ contains Γ and has left dimensionality [Δ:Γ] L = 2 then Δ is Galois over Γ On the other hand, we shall construct a class of examples where [Δ: Γ] L = 2 = [Δ:Γ] R , Γ of characteristic ≠ 2 and Δ is not Galois over Γ.
Visualization of Steam Injection in Fractured Systems Using Micromodels

We present visualization studies of hot water and steam injection in micromodel geometries that mimic a matrix-fracture system. Emphasis is placed on the matrix-fracture interaction during steam injection. We visualize the movement of steam and determine the conditions under which matrix penetration by steam occurs. More generally, the effectiveness of steam injection in displacing oil from the matrix is assessed. Displacement of oil was observed to occur by three mechanisms : a thermally-induced solution gas-drive, capillary imbibition of condensed water and displacement by steam, when the latter penetrated the matrix. Vaporization of light components at elevated temperatures generated an efficient solution-gas drive in the matrix, without the need for steam penetration. This also led to the formation of stable foam-like lamellae, which improved oil production by blocking the movement of steam and water in the fracture. This mechanism was also found to apply during hot water injection. Condensed water imbibed the matrix according to rules that govern imbibition of a fracture-matrix system. Steam penetration of the matrix occured when the steam rate exceeded a critical value, determined from drainage considerations. The results should be useful in modeling of steam injection in naturally fractured reservoirs.
The Drosophila melanogaster host model.

The deleterious and sometimes fatal outcomes of bacterial infectious diseases are the net result of the interactions between the pathogen and the host, and the genetically tractable fruit fly, Drosophila melanogaster, has emerged as a valuable tool for modeling the pathogen–host interactions of a wide variety of bacteria. These studies have revealed that there is a remarkable conservation of bacterial pathogenesis and host defence mechanisms between higher host organisms and Drosophila. This review presents an in-depth discussion of the Drosophila immune response, the Drosophila killing model, and the use of the model to examine bacterial–host interactions. The recent introduction of the Drosophila model into the oral microbiology field is discussed, specifically the use of the model to examine Porphyromonas gingivalis–host interactions, and finally the potential uses of this powerful model system to further elucidate oral bacterial-host interactions are addressed.
Predicting differential renal function using computerized tomography measurements of renal parenchymal area.

Purpose: We evaluated any correlation between measured renal parenchymal area on computerized tomography and differential function on 99mtechnetium-mercaptoacetyltriglycine renal scan to ascertain whether computerized tomography measurements could predict differential renal function.Materials and Methods: Between 2005 and 2007 we identified 111 patients who underwent computerized tomography and renal scan. Average renal parenchymal thickness was calculated by measurements made at the upper and lower poles of each kidney. The product of average renal parenchymal thickness and renal length was calculated bilaterally and the ratio of parenchymal area was compared to the differential shown on renal scan.Results: The average difference between predicted and observed renal function was 4.73% (Pearson's correlation coefficient 0.959). Patients with positive urine cultures at renal scan were compared to the other 89. The average functional difference was 6.54% vs 4.28% (Pearson's correlation 0.955 vs 0.965, p = 0...
CHROMOPHORE REORIENTATIONS IN THE EARLY PHOTOLYSIS INTERMEDIATES OF BACTERIORHODOPSIN

The photoselection-induced time-resolved linear dichroism of a bacteriorhodopsin suspension of purple membrane from 350 to 750 nm is measured by a new pseudo-null measurement technique. In combination with time-resolved absorption measurements, these linear dichroism measurements are used to determine the reorientation of the retinal chromophore of bacteriorhodopsin from 50 ns to 50 microseconds after photolysis. This time range covers the times when the K photointermediate decays to form L, as well as the early times during the formation of the M intermediate in the photocycle. An analysis of the photoselection-induced linear dichroism measured directly, along with the absorbance changes polarized parallel to the linearly polarized excitation, shows that the anisotropy is invariant over this time period, implying that the photolyzed chromophore rotates less than 8 degrees C with respect to unphotolyzed chromophores during this part of the photocycle.
TSLP is involved in expansion of early thymocyte progenitors

Thymic stromal derived lymphopoietin (TSLP) is preferentially and highly expressed in the thymus, but its function in T cell development is not clear. We report here that TSLP, independently or in combination with IL-7, enhances thymopoiesis in the murine fetal thymic organ culture (FTOC) model. Furthermore, TSLP preferentially increases the number and proliferation of the (DN1 and DN2) pro-T progenitor cells, and FTOC lobes from TSLP receptor-null mice show a decreased number of these cells. Finally, DN1-DN2 cells expanded with TSLP in vitro are functional T progenitors that are able to differentiate into mature T cells in fetal or adult thymus organs. Together, these data suggest that TSLP plays an important role in expansion of thymocyte progenitors and may be of value for expanding T progenitor cells in vitro.
Derivation of an analytical model to calculate junction depth in HgCdTe photodiodes

An enhanced analytical model is derived to calculate the junction depth and Hg interstitial profile during n-on-p junction formation in vacancy-doped HgCdTe. The enhanced model expands on a simpler model by accounting for the Hg interstitials in the p-type, vacancy-rich region. The model calculates junction depth during both the initial, reaction-limited regime of junction formation and the diffusion-limited regime. It also calculates junction depth under conditions when the abrupt junction approximation of the simpler model fails. The enhanced model can be used to determine the limits of the annealing conditions and times for which the junction depth calculated analytically is valid. The decay length of interstitials into the p-type region estimated analytically places an upper bound on the grid spacing needed to accurately resolve the junction in a numerical simulation.
Finite-difference — time-domain analysis of a high-frequency microwave connector

In this study, the finite-difference-time-domain method (FDTD) is used to analyze a complex packaging component, namely, a high-frequency microwave connector. Because the FDTD technique is easy to use and very flexible, it can be employed to analyze packaging components whose geometrical configurations are highly complex. In contrast, other approaches, for example, the method of moments (MoM), the method of lines (MoL), and the finite-element method (FEM), are more difficult to apply to complex geometries. In this article we employ the FDTD method to investigate the scattering parameters of a microwave connector and validate the numerical results by comparing them with measured data. © 1995 John Wiley & Sons, Inc.
Microstructure of a 12H Mg‐Si‐Al‐O‐N Polytype Alloy: Intergranular Phases and Compositional Variations

The mil-restructure of a 12H polytype alloy having a composition Mg, 86A1,67Si2.47O3.19N3.81 was examined by transmission electron microscopy with the techniques of X-ray spectroscopy microanalysis and lattice fringe imaging. An intergranular film (2.5 to 10 nm thick) is present at the majority of two-grain junctions. At several boundaries, the polytype fringe spacing decreases abruptly near the boundary, indicating a change in poiytype structure and composition. The intergranular phase at three-grain junctions is partially crystallized and the crystalline regions incorporate principally Mg and Si cations, whereas the surrounding amorphous phase contains Si, Mg, Ca, and Al cations. The composition of one of the glassy regions is calculated as about Mg2.5Si0.42Al0.13Ca0.95(ON).
Potential cerebral perfusion agents: synthesis and evaluation of berberine analogues

A partir de chlorhydrate de berberine, synthese de tetrahydro-7,8,13,13a berberine marquee T par reduction par le tetrahydroborate de sodium tritie et synthese de p-iodo (I125)benzyl-8 tetrahydro-7,8,13,13a berberine par reaction avec le bromure de p-bromobenzyl magnesium suivie de reduction, puis de reaction d'echange d'halogene par Na 125 I. Evaluation biologique
The phase difference between length of day and atmospheric angular momentum at subannual frequencies and the possible role of core-mantle coupling

We examine discrepancies in the angular momentum budget of the Earth on subannual timescales. We find that for signals with long periods (> 30 days) the phase of the length of day (ΔLOD) significantly leads that of the atmospheric angular momentum (AAM). The discrepancy has an amplitude of ≃ 15% of the observed AAM at periods of around 100 days. We show that if changes in the ΔLOD are driven by the atmosphere, then this is diagnostic either of the importance of the oceans or of dynamical coupling between the core and mantle for these frequencies. We find that a simple model of core-mantle coupling can cause a phase lead of ΔLOD of the correct magnitude. We attempt to fit the transfer function with a simple three-layer model of the Earth, treating the core as a rotating solid body coupled to the mantle by a specified function. Although our simple model can supply sufficient phase lead of the ΔLOD, the fit to the frequency dependence is poor and it can not fit the magnitude of the transfer function. Nevertheless, this suggests that core-mantle coupling is a plausible explanation of the observed phase difference. Better fits might be obtained with more realistic models of the core.
All on Board? Changing the Culture of Couplet Care

Paper Presentation Purpose for the Program For many years traditional couplet care has separated mothers and newborns shortly after birth. Studies have shown the detrimental effects on mothers and newborns when care is given in separate locations. Proposed Change Before the implementation of couplet care, this organization separated mothers from their newborns when providing care during transition and at night in the nursery. Using the Iowa model of evidence‐based practice to improve quality care, we developed evidence‐based practice changes that were guided by nurses that questioned the rational (which was not supported by the literature) for continued separation of mothers and newborns. The planning phase included development of an interdepartmental team, literature review, survey of comparable facilities, and piloting models of couplet care. Implementation, Outcomes, and Evaluation In 2011, the implementation process began with interdepartmental and interdisciplinary meetings lead by the clinical nurse specialist and staff development instructors to identify barriers and assist with the change process. Discussion at unit based committees provided staff input and feedback for the change. Education was provided for registered nurses, ancillary staff, and physicians. Verbal and written information also was provided to patients at childbirth classes and prenatal visits. Skin‐to‐skin contact began in the delivery room for all healthy term and late preterm newborns. After transfer to the maternity unit skin‐to‐skin contact was uninterrupted throughout the transition period. The journey to the standard of couplet and family‐centered care has had many challenges and rewards. Changing the nursing culture to embrace this new practice has been challenging. Some staff nurses are resistant to change their delivery of care. The mother's exhaustion often was sited as the reason for the newborn being returned to the nursery at night. Some staff members use pacifiers to comfort newborns. Difficulty in maintaining sustained practice changes contribute to the challenges. Positive outcomes related to the nonseparation of new mothers and newborns focus on both patients and staff. Increased patient satisfaction scores, decreased neonatal intensive care unit admissions, reduced incidences of hypoglycemia, as well as positive feedback from families about their experience validate the success of our care model. Staff satisfaction and interdepartmental teamwork related to bedside report for new admissions have improved. Though there have been many successes and challenges along the way, our organization is committed to evolve a culture of best practice for couplet care. Implications for Nursing Practice The nursing culture shifted from traditional care to evidence‐based care.
Dome growth and destruction during the 1989–1990 eruption of redoubt volcano

Abstract Much of the six-month-long 1989–1990 eruption of Redoubt Volcano consisted of a dome-growth and -destructive phase in which 14 short-lived viscous silicic andesite domes were emplaced and 13 subsequently destroyed. The life span of an individual dome ranged from 3 to 21 days and volumes are estimated at 1 × 10 6 to 30 × 10 6 m 3 . Magma supply rates to the vent area averaged about 5 × 10 5 m 3 / day for most of the dome-building phase and ranged from a high of 2.2 × 10 6 m 3 per day initially to a low of 1.8 × 10 5 m 3 per day at the waning stages of the eruption. The total volume of all domes is estimated to be about 90 × 10 6 m 3 and may represent as much as 60–70% of the volume for the entire eruption. The site of 1989–1990 dome emplacement, like that in 1966, was on the margin of a north-facing amphitheatre-like summit crater. The domes were confined on the east and west by steep cliffs of pre-eruption cone-building volcanic rocks and thus were constrained to grow vertically. Rapid upward growth in a precarious site caused each dome to spread preferentially to the north, resulting in eventual gravitational collapse. As long as the present conduit remains active at Redoubt Volcano, any dome formed in a new eruption will be confined to a narrow steeply-sloping gorge, leading to rapid vertical growth and a tendency to collapse gravitationally. Repetitive cycles of dome formation and failure similar to those seen in 1989–1990 are probably the norm and must be considered in future hazard analyses of Redoubt Volcano.
Screening and Relativistic Effects on Beta-Spectra

The effect of screening by atomic electrons on the form of allowed beta-ray spectra of the Fermi theory is calculated approximately, with the assumption of a screened potential based on the Thomas-Fermi model of the atom. The apparent deviation from theory caused by neglecting screening is given for the beta-emitters ${\mathrm{S}}^{35}$, ${\mathrm{Cu}}^{64}$, and RaE. Another smaller source of error in interpreting experimental results is the use of the non-relativistic approximation to the Coulomb correction factor. These effects cannot be neglected in an accurate analysis of data for Cu and heavier elements.
Surface reduction study of monoazo dyes by adsorptive square wave voltammetry

Abstract The surface reduction behavior of nine monoazo dyes at the static mercury drop electrode has been studied by adsorptive square wave voltammetry. Three types of surface reduction behavior are seen among the nine azo dyes. Two of them are modeled as a two-step mechanism in which the first step is a quasi-reversible reduction followed by a totally irreversible reduction. For those dyes having strong electron-donating groups such as amino or dimethylamino, the second reduction occurs at a potential almost the same as that of the first, and only one peak is observed. The second step gradually separates from the first step as the pH-value of the solution increases. For those azo dyes having methoxy or hydroxy substituents, two peaks are observed; one is quasi-reversible, the other is totally irreversible. The second, irreversible step gradually overlaps the first step as the pH-value of the solution decreases. The third type voltammogram of these monoazo dyes displays a single irreversible peak that is modeled as a four-electron one-step irreversible reduction. These surface reduction behaviors are quantitatively explained by the proposed models. Kinetic parameters for these surface reactions are obtained by non-linear least squares (COOL) analysis of the voltammograms. These techniques are useful both for establishing mechanisms and chemical analysis.
Homogenization of magnetostrictive particle-filled elastomers using an interface-enriched reproducing Kernel particle method

A formulation is proposed for homogenization of magnetostrictive particle-filled elastomers (MPFE) based on an interface-enriched reproducing kernel particle method. A variational equation for obtaining the local fluctuating deformation of MPFE is introduced. The magnetostrictive effect in the metal inclusion is modeled as an eigen-deformation. An interface-enriched reproducing kernel approximation with embedded derivative discontinuities on the material interface is presented. This approach does not require additional degrees of freedom in the approximation of displacement field for the interface conditions compared to the conventional reproducing kernel approximation. Microscopic solution and homogenized constitutive behavior of uniaxial tension and simple shear deformation of MPFE are presented.
Changes in dopamine D2-receptor modulation of the hypoxic ventilatory response with chronic hypoxia

Abstract Modulation of the hypoxic ventilatory response (HVR) by dopamine D2-receptors (D2-R) in the carotid body (CB) and central nervous system (CNS) are hypothesized to contribute to ventilatory acclimatization to hypoxia. We tested this with blockade of D2-R in the CB or CNS in conscious rats after 0, 2 and 8 days of hypoxia. On day 0, CB D2-R blockade significantly increased V i and frequency (f r ) in hyperoxia ( Fi O 2 =0.30), but not hypoxia ( Fi O 2 =0.10). CNS D2-R blockade significantly decreased fR in hypoxia only. On day 2, neither CB nor CNS D2-R blockade affected V i or f r . On day 8, CB D2-R blockade significantly increased hypoxic V i and f r . CNS D2-R blockade significantly decreased hypoxic V i and f r . CB and CNS D2-R modulation of the HVR decreased after 2 days of hypoxia, but reappeared after 8 days. Changes in the opposing effects of CB and CNS D2-R on the HVR during chronic hypoxia cannot completely explain ventilatory acclimatization in rats.
Strategies for Prostate Cancer Gene Therapy

Gene therapy for prostate cancer is a relatively new experimental treatment modality and several different therapeutic approaches are being considered. Prostate cancer is the most commonly diagnosed cancer in males and has unique features that make it ideal for gene therapy. Although prostate cancer that is confined to the gland can be cured in many of the patients using local treatments (radical prostatectomy or irradiation therapy), the long-term failure rate of these therapies suggests that cancers can metastasize relatively early in the course of the disease. Once prostate cancer has metastasized there are no curative therapies. The greatest challenge in the treatment of advanced prostate cancer is to access and eliminate metastatic cells. Therefore, successful prostate cancer gene therapy will ultimately require an effective strategy to kill cancer cells both at the site of the primary tumor and at distant metastatic sites. In this article we review many aspects of gene therapy specifically relevant for prostate cancer. We discuss the unique advantages and disadvantages of nonviral and viral gene delivery systems. Evidence that gene delivery directly into tumors, in situ, is effective for prostate cancer is presented. We provide a broad review of three general approaches or strategies for prostate cancer gene therapy: corrective, cytoreductive, and immuno-modulatory gene therapy. Replacement of the tumor suppressor gene p53 is the best studied example of corrective gene therapy. The cytoreductive gene therapy that has been used most extensively is herpes simplex virus thymidine kinase (HSV-tk) combined with the prodrug ganciclovir. Immunomodulatory gene therapy approaches such as enhancement of cancer cell recognition, e.g. with antigen encoded gene vaccine approaches, and augmentation of the cellular immune response with specific immunomodulatory molecules such as interleukin-12 have the potential to effectively treat both local prostate cancer and distant metastases.
Coronary artery bypass grafting versus stenting for unprotected left main coronary artery disease: where lies the body of proof?

The standard of care for left main coronary artery disease is coronary bypass surgery (CABG). The efficacy and survival advantage of CABG have resulted in CABG being established practice since the 1970s.1–3 Further improvements in late survival have been achieved with arterial grafting, which is practiced routinely even in patients more than 80 years of age.4–6 Article p 2374 Technical advances in percutaneous coronary interventions (PCIs) and stent technology have emboldened the interventional cardiology community to test the feasibility of and document the procedural results for stenting the left main coronary artery.7–14 Surgical approaches have a distinct advantage in that they can ignore the complexity and location of the left main coronary lesion, because bypass grafts are placed distally to the left anterior descending and circumflex coronary arteries. In addition, complete revascularization is easily accomplished. The feasibility and success of PCI require an evaluation of lesion complexity. The probability of procedural success requires a consideration of whether the obstructing plaque involves the ostium of the coronary artery, the body of the left main, or the length of the left main and whether disease involves the bifurcation with or without extension into the left anterior descending or circumflex coronary arteries. Ostial or body obstructions in a long left main vessel are more desirable to stent than bifurcation or trifurcation lesions.15–18 An additional consideration is the possibility of sudden stent thrombosis early or late after the use of drug-eluting stents (DES) or bare-metal stents. Such events in the left main coronary artery would have catastrophic consequences that most likely would result in sudden death.19–23 Current recommendations for DES are to continue dual-antiplatelet therapy for prolonged periods of time (>6 months or indefinitely), because stent healing with endothelium is incomplete. This protocol may be particularly risky in elderly …
Diabetes, sleep disorders, and male sexual function.

Abstract The prevalence and role of sleep disorders in the sexual problems of diabetic patients remain unexplored. This study was conducted on 40 diabetic men carefully screened to exclude the confounding effects of other medical illnesses or drugs likely to impair sexual function and 40 age-matched healthy volunteers. They underwent an extensive psychosexual interview, medical and psychiatric evaluations, and three recorded nights in a sleep laboratory. Electroencephalogram, eye movements, muscle tone, and nocturnal penile tumescence were monitored continouusly. Respiratory airflow and bilateral anterior tibialis recordings were obtained during the first sleep session. Diabetic men had significantly higher prevalences of respiratory and periodic leg movement disturbances during sleep. There was clinical, although not nocturnal penile tumescence, evidence suggesting that respiratory abnormalities during sleep are associated with erectile difficulties in diabetic men. Future studies should include blood oxygenation and respiratory effort measures to clarify the significance of sleep-related airflow disturbances in diabetic patients.
Revolution in Fan Heat Sink Cooling Technology to Extend and Maximize Air Cooling for High Performance Processors in Laptop / Desktop / Server Application

The trend of the processor performance and heat dissipation have been increased significantly every year. In the year 2000, the clock speed of processors used in Personal Computers (PC) was approximately 1GHz and heat dissipation approximately 20 W, but in the year 2004 the processor’s clock speed is higher than 3 GHz and the heat dissipation is approaching 100 W. Heat dissipation has increased but in contrast the size of die on the processor has reduced or remained the same size and thus the heat flux is critically high. The heat flux is about 10–15 W/cm2 in the year 2000 and could reach 100 W/cm2 in 2005. The purpose of this paper is to provide an overview of practical various cooling solutions including the use of heat pipes and vapor chambers for cooling high power processors in a confined space of PCs. This paper discusses how to extend the air cooling capability and maximize its performance. Included in this paper are the design, data, photos and discussion of various fan sink air cooling designs showing how the design changes can push the limit of the air cooling capability.Copyright © 2005 by ASME
Women's roles in voluntary medical male circumcision in Nyanza Province, Kenya.

Women are an important audience for voluntary medical male circumcision (VMMC) communication messages so that they know that VMMC provides only partial protection against HIV. They may also be able to influence their male partners to get circumcised and practice other HIV protective measures after VMMC. This study was conducted in two phases of qualitative data collection. Phase 1 used in-depth interviews to explore women’s understanding of partial protection and their role in VMMC. Phase 2 built on the findings from the Phase 1, using focus groups to test VMMC communication messages currently used in Nyanza Province and to further explore women’s roles in VMMC. Sixty-four sexually active women between the ages of 18 and 35 participated. In Phase 1, all women said they had heard of partial protection, though some were not able to elaborate on what the concept means. When women in Phase 2 were exposed to messages about partial protection, however, participants understood the messages well and were able to identify the main points. In Phases 1 and 2, many participants said that they had discussed VMMC with their partner, and for several, it was a joint decision for the man to go for VMMC. These findings suggest that current VMMC messaging is reaching women, though communications could more effectively target women to increase their ability to communicate about partial HIV protection from VMMC. Also, women seem to be playing an important role in encouraging men to get circumcised, so reaching out to women could be a valuable intervention strategy for increasing VMMC uptake and promoting use of other HIV protective measures after VMMC.
Lysophosphatidic acid induces human mast cell activation in an IL-4-dependent manner

Abstract Rationale Lysophosphatidic acid (LPA) is a lipid constituent of human serum that functions as a signaling molecule through binding to 4 known G protein-coupled receptors, designated LPA1-4. LPA has previously been shown to act as a growth factor for human mast cells (hMCs) cultured under serum-free conditions. We now investigate the role of LPA in hMC activation. Methods hMCs were cultured from umbilical cord-derived mononuclear cells using serum-free medium with recombinant human stem cell factor, IL-6, IL-10, and supplemental LPA (5μM). Cells were primed with IL-4 (0.1-50 ng/mL) for up to 5 days. RT-PCR was performed to characterize LPA receptor expression. LPA-induced calcium flux was measured in Fura-2AM-loaded hMCs. For activation studies, hMCs were incubated with LPA (10-50μM) for 30 minutes to 6 hours. Histamine release, eicosanoids, and cytokine production were measured by ELISA. Kit (CD117) expression was measured by FACS analysis. Results mRNA encoding LPA1-4 are expressed by hMCs. LPA (20-50μM) induced calcium flux. LPA (10-50μM) induced MIP-1β production only in the presence of IL-4 priming. IL-4 enhanced MIP-1β generation in a dose-dependent manner, reaching 53 ± 13% (mean ± SEM, n=4) of the level produced by FcϵRI cross-link, compared with negligible levels in unprimed cells (p=0.04). In contrast, LPA did not induce hMC exocytosis or eicosanoid production. IL-4 priming significantly down-regulated Kit expression. Conclusions LPA induces cytokine generation by hMCs in an IL-4-dependent manner by a pathway that does not elicit exocytosis or eicosanoid generation.
Gastrointestinal symptoms and patient satisfaction more than 1 year after laparoscopic Nissen fundoplication

Symptoms from poorly controlled gastroesophageal reflux disease (GERD) such as heartburn and regurgitation often resolve after laparoscopic Nissen fundoplication. Unfortunately, new gastrointestinal symptoms such as bloating may occur for some patients. Accurate data regarding the gastrointestinal symptoms experienced by patients who have had a laparoscopic fundoplication may help patients to make more informed decisions about pursuing surgery for their reflux disease. Patients more than 12 months after a laparoscopic Nissen fundoplication were mailed symptom surveys. Before surgery, all the patients had medically refractory esophageal symptoms (heartburn, regurgitation, or both). Surveys included the Gastrointestinal Quality of Life Index (GIQLI) and questions regarding satisfaction, reintervention, and medication use. Responses for individual GIQLI items were evaluated to determine the gastrointestinal symptoms experienced by fundoplication patients and the relationship of these symptoms to patient satisfaction. Of the 76 patients eligible for inclusion in the survey, 48 returned complete surveys (63%). The mean time since surgery was 28 ± 9 months. No patient experienced frequent regurgitation, and few (10%) reported frequent heartburn at follow-up assessment. No patient required redo fundoplication during the follow-up period. Acid reduction medications were resumed by 25% of the patients, but not all of these patients resumed medications for recurrent GERD symptoms (15% total). After surgery, frequent bloating (21%) and excessive flatus (46%) were often noted. Satisfaction with the results of surgery was high, including 83% of the patients. Few patients report frequent regurgitation or heartburn after laparoscopic Nissen fundoplication. Although some patients resume acid reduction medications, many do so for reasons other than recurrent GERD symptoms. Most fundoplication patients are quite satisfied with the symptomatic results of surgery, although frequent functional gastrointestinal symptoms are common.
Measurement of the Hydrogen Spin-Exchange Cross Section with the Hydrogen Maser

The oscillation characteristics of the hydrogen maser under the influence of hydrogen-hydrogen spin-exchange collisions are described and discussed. Using experimental data from an oscillating hydrogen maser, the hydrogen spin-exchange cross section is calculated. A value of $\ensuremath{\sigma}=2.65\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}15}$ ${\mathrm{cm}}^{2}$ at room temperature is obtained and compared with previously published values. A brief discussion on a possible increase of the maser output power is given.
Temporal rearrangement of electronic densities in slow atomic collisions

Electronic rearrangement is a common occurrence in interactions of an atom with other atoms or with solid surfaces and in molecular photodissociation by visible and UV light. In this contribution, the emphasis is on the way properties change over time, as a system progresses from its initial to its final state in a collision. An overview is presented of our recent work describing electronic rearrangement in terms of coupled differential equations for electronic orbitals and nuclear degrees of freedom. An eikonal/(time-dependent Hartree–Fock) approximation is described and a new compact formulation is given in terms of operators in Liouville space, for both small and extended molecular systems. A method is described for treating the coupling of degrees of freedom with very different time scales. The method is illustrated with selected results for temporal atomic population changes in ion–atom and ion–solid surface interactions. © 1994 John Wiley & Sons, Inc.
Should "lane formation" occur systematically in driven liquids and colloids?

We report on nonequilibrium molecular dynamics simulations of binary mixtures of particles in a color field. Both nonequilibrium molecular dynamics and Brownian dynamics generally assume that the mechanical noise is of thermal origin only and that, at a given temperature, its amplitude remains constant however strong the applied field is. We show that this postulate systematically results in the strong ordering of particles into lanes. By applying a nonequilibrium molecular dynamics method which does not exert any constraint on the noise amplitude, we show that releasing this constraint prevents the systematic ``lane formation'' from occurring. We observe the onset of density inhomogeneities and jamming instead. This behavior is reminiscent of the shear-thickening regime observed experimentally on colloidal suspensions and in simulations taking into account hydrodynamic interactions.
Local axial migration and spreading rate variations, East Pacific Rise, 31°S

Abstract Mapping and analysis of marine magnetic anomalies generated during the past 3.78 m.y. at the East Pacific Rise crest near 31°S reveals a history of ongoing small-scale migration of the spreading center. The axis first became curved and then broke when the curvature became too severe, forming a 10-km offset. The offset healed rapidly and the topographic axis of the rise is now continuous and essentially linear. Sea-floor spreading has occurred asymmetrically in this area with east and west flank rates of 86 and 77 mm/yr, respectively, since 2.41 m.y. ago. Total spreading rates show an overall decline from 176 to 145 mm/yr prior to the Jaramillo event, 0.9 m.y. ago. For the last 0.7 m.y. the total spreading rate has been 162 mm/yr.