cssi/SciSciGPT-SciSciNet huggingface dataset:
State of the art in electronic detectors for portal imaging

Summary form only given. The first clinically-practical, electronic portal imaging devices, which were introduced over a decade ago, spurred the exploration of the role of digital imaging in localization and verification for radiotherapy. However, these technologies, based on lens and fiber-optic-coupled phosphor-camera systems and on liquid ionization chambers, generally fail to provide imaging performance equivalent to that of the current gold standard, radiotherapy film cassettes. While incremental improvements in these technologies have been achieved, these and other limitations have encouraged the development of fully solid-state, digital imagers based on thin-film electronics. This new technology, referred to as active matrix, flat-panel imagers (AMFPIs), employs large monolithic imaging arrays (presently, up to 40/spl times/40 cm) and provides image quality superior to that of conventional film systems. AMFPIs are compact, allow radiographic or fluoroscopic readout, and provide images exhibiting a high degree of spatial and contrast information content over a wide range of doses and therapy energies. This technology also lends itself to diagnostic projection and CT imaging as well as dosimetry-all of which are being examined in the context of treatment room needs. In this presentation, the current status of electronic detectors for portal imaging is reviewed and anticipated future developments are discussed.
Online or face‐to‐face? Experimenting with different techniques in teacher training

This paper illustrates a 5-year case study (from 2001 to 2005) regarding a course in educational technology that involved from 100 to 150 student teachers per year for a total of more than 500 trainees. Since the first version of the course, which was entirely based on a face-to-face approach, computer mediated collaborative learning techniques have gradually been introduced into the training program. The paper outlines the main problems faced in the various versions of the course, where different combinations were experimented with, and discusses the solutions adopted. The difficulties concern the demands of a large, diversified population and the methodological problems related to the non-neutrality of the introduction of online learning in the socio-cultural and organizational context of the study. The solutions include a highly flexible course design and a good balance and strict integration between traditional and online training techniques in the delivery of the course and in the assessment of trainees. Finally, we suggest possible directions for further research aimed at facilitating the infusion of online techniques in initial teacher training.
Fuzzy power series

The paper discusses the convergence of an infinite series of fuzzy numbers. In particular, a power series involving fuzzy numbers is considered. The ultimate goal of the paper is to produce a power series solution to a fuzzy differential equation.
GDNF is regulated in an activity-dependent manner in rat skeletal muscle

Glial cell line-derived neurotrophic factor (GDNF) is produced by skeletal muscle and affects peripheral motor neurons. Elevated expression of GDNF in skeletal muscle leads to hyperinnervation of neuromuscular junctions, whereas postnatal administration of GDNF causes synaptic remodeling at the neuromuscular junction. Studies have demonstrated that altered physical activity causes changes in the neuromuscular junction. However, the role played by GDNF in this process in not known. The objective of this study was to determine whether changes in neuromuscular activity cause altered GDNF content in rat skeletal muscle. Following 4 weeks of walk-training on a treadmill, or 2 weeks of hindlimb unloading, soleus, gastrocnemius, and pectoralis major were removed and analyzed for GDNF content by enzyme-linked immunosorbant assay. Results indicated that walk-training is associated with increased GDNF content. Skeletal muscle from hindlimb-unloaded animals showed a decrease in GDNF in soleus and gastrocnemius, and an increase in pectoralis major. The altered production of GDNF may be responsible for activity-dependent remodeling of the neuromuscular junction and may aid in recovery from injury and disease.
Treatment of erectile dysfunction in the obese type 2 diabetic ZDF rat with adipose tissue-derived stem cells.

ABSTRACT Introduction Erectile dysfunction (ED) is a major complication of type 2 diabetes, and many diabetic men with ED are refractory to common ED therapies. Aim To determine whether autologous adipose tissue-derived stem cells (ADSCs) injected into the penis of impotent type 2 diabetic rats improve erectile function. Main Outcome Measures Blood glucose levels, intracavernous pressure (ICP) increase upon cavernous nerve (CN) electrostimulation, and immunohistochemistry. Methods Twenty-two male Zucker diabetic fatty (ZDF) rats were used. At 22 weeks of age, all the animals underwent unilateral CN electrostimulation and ICP measurement to confirm impotence. Paragonadal adipose tissue was harvested to procure ADSCs. The impotent animals were randomized to ADSC treatment and sham control groups. At 23 weeks of age, the treatment group animals underwent a penile injection of 1 million ADSCs; the control group animals received vehicle only. Erectile function studies were repeated at 26 weeks of age, followed by tissue harvest. Results The rats developed diabetes within the first 10 weeks of age. At 22 weeks of age, 20 out of the 22 rats presented with ED. The post-treatment ICP increase during CN stimulation and ICP increase/mean arterial pressure were significantly higher in the treatment group compared with controls. Three weeks after injection into the corpus cavernosum, only a small number of BrdU-labeled ADSCs was detectable within corporal tissue of the treatment group. There was a significant increase in neuronal nitric oxide synthase (nNOS) in the penile dorsal nerve and in the number of endothelial cells in the corpora cavernosa of the rats in the treatment group. Conclusion Autologous ADSCs injected into the penis were effective to improve erectile function and to alter the microarchitecture of the corpus cavernosum. Since the number of ADSCs retained in the corpus cavernosum is very small, we postulate that their paracrine function, not trans-differentiation to smooth muscle or endothelial cells, is responsible for the improvement in penile function. Garcia MM, Fandel TM, Lin G, Shindel AW, Banie L, Lin C-S, and Lue TF. Treatment of erectile dysfunction in the obese type 2 diabetic ZDF rat with adipose tissue-derived stem cells.
Characterization of isotropic solids with nonlinear surface acoustic wave pulses

The nonlinear propagation of high-amplitude surface acoustic wave (SAW) pulses in two isotropic materials, polycrystalline aluminum and synthetic fused silica, was studied and exhibited qualitatively different types of nonlinear behavior. A single SAW pulse excited by a nanosecond laser pulse through a strongly absorbing layer was detected at two probe spots along the propagation path with a dual-probe-beam deflection setup. In this way the nonlinear changes of the SAW pulse shape were observed. For aluminum, the compression of the SAW pulse and formation of one negative (inward the solid) narrow peak in the registered normal surface velocity and a shock front in the in-plane velocity were detected. This nonlinear behavior corresponds to a positive value of the nonlinear acoustic constant responsible for the local nonlinearity. For fused silica, the temporal extension of the SAW pulse and formation of two positive sharp peaks in the normal velocity related to two shock fronts in the in-plane velocity were registered. In this case the acoustic constant of the local nonlinearity is negative. The nonlinear acoustic constants for each material were evaluated by fitting the theoretical model based on the nonlinear evolution equation to the registered SAW pulses. The values obtained were found to be consistent with those calculated from nonlinear elastic moduli of the third order, measured previously with different techniques for similar materials. The characterization of solids by their nonlinear acoustic and elastic constants promises to be complimentary and more specific than the characterization based on the linear properties.
Organization of central auditory pathways in a teleost fish,Cyprinus carpio

1. Central auditory pathways were mapped in carp,Cyprinus carpio, by analyzing depth profiles of acoustic evoked field potentials (AEPs) and multiunit activity (MUA) in response to click stimuli. Central nuclei which respond to sound are not activated by lateral line stimulation, indicating that separate pathways are involved in processing these two sensory modalities in carp. 2. Two octaval nuclei within the carp medulla respond to sound, the descending octaval nucleus (DON) (Fig. 2) and the anterior octaval nucleus (AON) (Fig. 3). Single clicks produce localized MUA and negative AEPs with peak latencies of 6–8 ms in both nuclei. 3. In the midbrain, best AEP and MUA responses to auditory stimuli are found within the medial torus semicircularis (TS) (Fig. 4). A monophasic negative AEP, with a latency of 8–14 ms, is particularly prominent within the upper layers of the torus. Earliest unit responses begin at 7 ms. 4. Auditory activity within the carp diencephalon is encountered during electrode penetrations of the central posterior thalamic nucleus (CP) (Fig. 5), one of three nuclei comprising the dorsal thalamus. The thalamic field potential is a monophasic negative wave with a peak latency ranging from 18 to 23 ms. Auditory units within the thalamus have an initial response latency of 17–19 ms. 5. Two auditory areas were found within the carp telencephalon. The first, believed to receive direct input from the auditory thalamus, is within a central zone (Dc) of the caudal dorsal telencephalon (Fig. 6). In this region, click stimuli produce a biphasic field potential with an initial negative peak at a latency of 35–44 ms. Maximal field potentials and multiunit activity are present at depths of 600–900 μm below the telencephalic surface. Longer latency biphasic field potentials and multiunit activity were recorded from a second auditory area located 500 μm caudal to this Dc field, within the ipsilateral dorsomedial (Dm) telencephalon (Fig. 7). Acoustic field potentials and unit latencies ranged from 46 to 69 ms. Neuronal responses to lateral line stimulation were also recorded within this telencephalic region. Some spatial segregation of auditory and lateral line units was apparent; lateral line units were recorded from the surface of the telencephalon to depths of 200 μm and acoustic units were found at depths of 100–400 μm. 6. In response to paired clicks (Fig. 8), AEPs recorded from medullary and midbrain auditory nuclei show a depression at intervals of less than 20 ms, but a rapid recovery of AEP amplitude at longer stimulus intervals, with 80–100% recovery at intervals of 80–100 ms. In contrast, auditory nuclei within the diencephalon and the telencephalon are extremely refractory to paired stimuli, with only 40–50% recovery at stimulus intervals of 100 ms. A similar finding was observed in response to click trains (Fig. 9).
The Current and Future Role of Aptamers in Electroanalysis

Aptamers have emerged as promising biorecognition elements in the development of electrochemical-based sensors. Aptamers, short oligonucleotides of DNA or RNA selected in vitro to bind a specific target, boast comparable binding affinities to antibodies, but possess superior chemical and biochemical stabilities. In addition, they require relatively simple synthesis protocols compared to the in vivo development of antibodies. Coupling the specific recognition abilities of aptamers with the selective and sensitive detection abilities of electrochemical signal transduction enables an almost unlimited number of strategies for generating biosensor architectures. Here we present a critical review of electrochemical sensing strategies employing aptamers through a presentation of the various signal transduction mechanisms employed. We find that, while there are numerous examples of aptamer-based sensors, the penetration of these platforms beyond the academic laboratory and proof-of-concept remains limited. We believe that aptamers will continue to be a focus in the development electrochemical sensors, although the limited number of proven aptamers hinders the progress of electrochemical, aptamer-based sensors from impacting fields beyond the electrochemical laboratory. However, considering the historical success of electrochemical-based sensors as well as the promise of selecting aptamers for virtually any target, we believe the future is bright for aptamers in electroanalysis and beyond. © 2014 The Electrochemical Society. [DOI: 10.1149/2.026405jes] All rights reserved.
Understanding the Ligand‐Directed Assembly of a Hexanuclear ThIV Molecular Cluster in Aqueous Solution

The electrochemical hydrolysis of thorium(IV) was monitored by a combination of high-energy X-ray scattering (HEXS) and NMR spectroscopy. Once formed, μ2-dihydroxo-bridged dimers remain stable in solutions of moderate pH until glycine is added, upon which the dimers rapidly condense to form hexanuclear clusters [Th6(μ3-O)4(μ3-OH)4]12+. In the absence of the dimers or glycine, the clusters do not form even if the solutions are stored over extended times.
A 13C NMR study of isonitrile transition metal complexes

Abstract The 13 C NMR spectra of a variety of isonitrile complexes have been studied. The isonitrile carbon shielding trend is consistent with the hypothesis that some π-back bonding occurs in zero oxidation state complexes but is not important in positive oxidation state complexes. A metal triad shielding trend is observed with the isonitrile complexes as has been found previously in carbonyl-, carbene-, and alkylmetal compounds.
A (Utopian?) socialist proposal for the reform of Major League Baseball.

Major League Baseball currently faces a crisis calling for radical reform of its operations. This article critically examines two recent reform proposals that call for a luxury tax on team salaries combined with revenue sharing that would bring greater financial and competitive parity among and between the league’s constituent teams. It is argued that these reforms do not go far enough in reestablishing the basis for fan loyalty that is the essence of the national pastime. A far superior reform model would have the teams become the property of the municipalities in which they operate, combined with a reserve clause that ties players to particular teams for their playing careers. A predetermined salary structure would make player compensation a function of longevity rather than the market. Salary cost control, in turn, would enable teams to price tickets at levels that would enable more families of modest means to attend games.
Murine alanine aminotransferase: cDNA cloning, functional expression, and differential gene regulation in mouse fatty liver.

Alanine aminotransferase (ALT) is a widely used index of liver integrity or hepatocellular damage in clinics as well as a key enzyme in intermediatary metabolism. In this study, we have cloned the complementary DNAs of murine homologues of human alanine aminotransferase 1 and 2 (ALT1 and ALT2). The deduced peptides of murine ALT1 (mALT1) and ALT2 (mALT2) share 87% and 93% identity, respectively, with their human counterparts at the amino acid level. Murine ALT genes localize to separate chromosomes, with mALT1 gene (gpt1) on chromosome 15 and mALT2 gene (gpt2) on chromosome 8. The murine gpt1 and gpt2 differ in messenger RNA expression: gpt1 is mainly expressed in liver, bowel, and white adipose tissue and gpt2 is highly expressed in muscle, liver, and white adipose tissue. Expression of recombinant mALT1 and mALT2 proteins in Escherichia coli (E. coli) produced functional enzymes that catalyze alanine transamination. The potential diagnostic value of ALT isoenzymes in liver disease was evaluated in an obese animal model. In fatty livers of obese mice, ALT2 gene expression is induced 2-fold, but ALT1 remains the same. Furthermore, in fatty liver, total hepatic ALT activity is elevated significantly by 30% whereas aspartate aminotransferase (AST) activity remains unchanged. In conclusion, these results indicate that ALT2 may be responsible for the increased ALT activity in hepatic steatosis and provide evidence that an ALT isoenzyme-specific assay may have more diagnostic value than the total ALT activity assay currently in clinical use. (HEPATOLOGY 2004;39:1297–1302.)
Diffuse Alveolar Hemorrhage due to Ketorolac Tromethamine

Drug-induced lung disease (DILD) is a common but frequently missed diagnosis. Therefore, a high index of clinical suspicion and familiarity with the clinical syndromes associated with DILD are important in making the diagnosis. Nonsteroidal anti-inflammatory drugs (NSAIDs) are one of the mostly commonly used classes of medications. NSAIDs are safe when used at prescribed doses. Side effects from use of NSAIDs are not uncommon and can affect almost every organ system in the body. NSAIDs are notorious for causing pulmonary toxicity, the common ones being bronchospasm and hypersensitivity reactions. Diffuse alveolar hemorrhage (DAH) secondary to NSAIDs is uncommon. Here, we report a case of DAH secondary to the use of ketorolac tromethamine.
Suppression of spurious modes via dummy electrodes and 2% frequency shift via cavity size selection for 1 GHz AlN MEMS contour-mode resonators

This paper reports on the application to 1 GHz AlN MEMS contour-mode resonators (CMR) of a spurious mode suppression technique based on the introduction of dummy electrodes and a method to shift the resonator center frequency by modifying its cavity size. The realization of wideband filters with CMRs is currently limited by the need to 1) enlarge the device capacitance (so as to minimize the inductive components in the matching network), 2) reduce in-band ripples and out-of-band spurs (which are introduced when the device capacitance is increased), and 3) shift the device center frequency by a large percentage (> 2%) to synthesize ladder/lattice configurations. This work addresses these 3 main challenges by optimizing the electromechanical response of AlN CMRs having a large static capacitance, synthesized by using thin AlN films of two different thicknesses (500 nm and 1 μm thick), sandwiched by Pt and Al electrodes and having a large number of fingers (up to 45). 3D COMSOL finite element model is used to analyze and/predict the resonator's behavior.
A new approach to deep desulfurization of gasoline, diesel fuel and jet fuel by selective adsorption for ultra-clean fuels and for fuel cell applications

In order to further reduce the sulfur content in liquid hydrocarbon fuels (gasoline, diesel fuel and jet fuel) for producing ultra-clean transportation fuels and for fuel cell applications, we explored a new desulfurization process by selective adsorption for removing sulfur (SARS). An adsorbent was developed and used for adsorption desulfurization of diesel fuel, gasoline and jet fuel at room temperature. The results indicate that the transition metal-based adsorbent developed in this work is effective for selectively adsorbing the sulfur compounds, even the refractory sulfur compounds in diesel fuels. The SARS process can effectively remove sulfur compounds in the liquid hydrocarbon fuels at ambient temperature under atmospheric pressure with low investment and operating cost. On the basis of the present study, a novel integrated process is proposed for deep desulfurization of the liquid hydrocarbon fuels in a future refinery, which combines a selective adsorption (SARS) of the sulfur compounds and a hydrodesulfurization process of the concentrated sulfur fraction (HDSCS). The SARS concept may be used for on-site or on-board removal of sulfur from fuels for fuel cell systems.
"Ephphatha, or, some advice to stammerers".

Take Bay-Leaves, Betony, Vervain, Marjoram, Rosemary, Lavender, each two Handfuls; boil them in a Lixivium of Wood-Ashes, three Quarts to two; adding at last, powdered Cloves, and Nutmeg, each two ...
Characterization of peptide diffusion into electropermeabilized neutrophils

Abstract The superoxide (O 2 − )-generating NADPH oxidase of human neutrophils consists of membrane-bound and cytosolic proteins that assemble in the plasma membrane of activated cells. To date, most of our understanding of the assembly of the NADPH oxidase has been obtained through the use of a cell-free assay, and a number of peptides that mimic regions of NADPH oxidase proteins have been shown to block oxidase assembly using this assay. However, the cell-free assay provides an incomplete representation of the assembly and regulation of the NADPH oxidase in vivo, and it has become necessary to develop methods for introducing biomolecules, such as peptides, into intact neutrophils where their effects can be investigated. One such method is electropermeabilization. Although this method has been used previously with human neutrophils, it has not been well characterized. We report here a detailed characterization of the electropermeabilized neutrophil assay system, including optimal conditions for membrane electropermeabilization with maximal retention of functional capacity, optimal conditions for analyzing the effects of experimental peptides, quantification of internalized peptide concentration, and molecular size limits for diffusion of molecules into these cells. Our results demonstrate that optimal neutrophil permeabilization (98–100%) can be achieved using significantly lower electrical fields than previously reported, resulting in the retention of higher levels of O 2 − -generating activity. We also found that biomolecules as large as 2.3 kDa readily diffuse into permeabilized cells. Analysis of flavocytochrome b peptides that were shown previously to inhibit NADPH oxidase activity in a cell-free assay demonstrated that these peptides also blocked O 2 − production in electropermeabilized human neutrophils; although at higher effective concentrations than in the cell-free system. Thus, electropermeabilized neutrophils provide a model system for evaluating the effects of peptides and other pharmacological agents in intact cells which closely mimic neutrophils in vivo.
Neuroretinitis Associated with Herpes Simplex Encephalitis in an Adult

A 48-year-old man who died of herpes simplex encephalitis had a bilateral papillitis at autopsy. Intranuclear inclusion bodies were especially numerous within the ganglion cells and inner nuclear layer of the macula and consisted of typical virions by electron microscopy. Contiguous spread from the brain to the eyes may have occurred via the optic nerves. Clinically, the disk and retinal changes were misinterpreted as being caused by papilledema. Papillitis should be included in the differential diagnosis of disk swelling in adults with suspected Herpesvirus hominis infection of the central nervous system.
Angiofollicular lymphoid hyperplasia--an unusual cause of axillary artery pseudoaneurysm.

Background Angiofollicular lymphoid hyperplasia (Castleman's disease) is a rare inflammatory condition. Its cause is unknown and it can be both localized and general. Eighty-six percent of lesions are found in the mediastinum or hilum, and 91% are of the hyaline vascular type. Although Castleman's disease is primarily involving the chest and retroperitoneum, it may also involve neck and axilla in 2-4% of cases. In this article, we present a very rare case of Castleman's disease causing axillary artery pseudoaneurysm. Methods and Results A 30-year-old woman patient presented with pulsating tumefaction of the left arm which was 3.5 × 10 cm in size, and became evident 15 days before admission. History revealed that she suffered trauma of the left upper arm in childhood; therefore, it was suspected that tumefaction may be due to a post-traumatic aneurysm. Duplex scan and multislice computed tomography examinations were performed and an axillary artery pseudoaneurysm was diagnosed. Since intraoperatively the tumefaction resembled the tumorous formation but not the aneurysmal wall, specimens were sent for pathohistological analysis. Arterial reconstruction was performed using autologous vein graft. Pathohistological findings showed vascular type of angiofollicular lymphoid hyperplasia. Conclusion Although angiofollicular lymphoid hyperplasia is rarely localized in the axillary area, this disease should also be considered when axillary artery pseudoaneurysm is diagnosed.
Read and write processes, and head technology for perpendicular recording

In this paper, we present a review of the write and read processes in perpendicular magnetic recording. We also discuss their impact, based on recording physics aspects, on design considerations for writers and readers. For the write process, we discuss fundamental write-ability limitations as well as possible paths to ultra-high areal density perpendicular recording. The impacts of different medium designs, geometrical scaling, and the breakdown of scaling, both in terms of write-ability and transition curvature, are shown based on different modeling techniques, including analytical formulas, finite element modeling (FEM), and micromagnetic simulations. Basic design rules as well as alternative designs that enable high areal density are briefly explained. For the read-back process, the relation between reader signal to noise ratio (SNR) and resistance, as well as reader resistance shunt and spacing loss, are discussed. Finally, we use a simple example to illustrate, both from a write as well as a read-back perspective, the complicated nature of perpendicular recording systems, and how different medium designs impact recording head technology for ultra high density perpendicular recording.
Metabolic basis for disorders of purine nucleotide degradation

Purine nucleotide degradation refers to a regulated series of reactions by which human purine ribonucleotides and deoxyribonucleotides are degraded to uric acid in humans. Two major types of disorders occur in this pathway. A block of degradation occurs with syndromes involving immune deficiency, myopathy or renal calculi. Increased degradation of nucleotides occurs with syndromes characterized by hyperuricemia and gout, renal calculi, anemia or acute hypoxia. Management of disorders of purine nucleotide degradation is dependent upon modifying the specific molecular pathology underlying each disease state.
Immersion foot. A problem of the homeless in the 1990s.

The syndrome of immersion foot is being seen with increasing frequency among the homeless population. It represents the effects of injury by water absorption in the stratum corneum of the skin of the feet. The taxonomy of this disorder is confusing and the many colorful pseudonyms should probably be dropped in favor of a simple classification based on the temperature of the water and the duration of exposure. When uncomplicated by infection or ischemic injury, immersion foot will quickly resolve with conservative measures only. More complicated cases may require antibiotics and surgical treatment. This syndrome may be exacerbated by disturbances of cognition, peripheral neuropathy, peripheral vascular disease, or the use of tobacco or vasoconstrictor drugs such as cocaine. A major contributing factor seems to be lack of shelter in the homeless population. Attention to foot care problems among the homeless and education concerning preventive measures are incumbent on physicians who care for the indigent. ( Arch Intern Med. 1991;151:785-788)
Anion-trapping and polyanion electrolytes based on acid-in-chain borate polymers

Abstract Oligoether branched-and-spaced “acid-in-chain” polymers, with variable length side chains attached to the acidic borons have been prepared by a simple two-step reaction sequence. These may be used as anion-retarding hosts for “salt-in-polymer” electrolytes or, alternatively, may be converted to polyanionic electrolytes by reacting with strong Lewis base anions. High ionic conductivities, reaching 7.6×10 −5 S cm −1 at 25 °C have been obtained for the former case, using LiTFSI:B proportions of 1:1, and optimized side chain and spacer lengths. The electrochemical windows are wide enough (>4.5 V) for most applications.
Serum protein changes during metamorphosis in Ambystoma tigrinum.

1. 1. The total protein (g %) of the sera of Ambystoma tigrinum does not increase after metamorphosis. 2. 2. There was a relative increase in the anadol migrating fraction of fastest electrophoretic mobility. 3. 3. The fastest anadol migrating fraction is considered an albumin on the basis of its concentration in the sera, electrophoretic mobility and dye binding capacity.
Analysis of cell cycle phases and progression in cultured mammalian cells

Fluorescence activated cell sorting (FACS) analysis has become a standard tool to analyze cell cycle distributions in populations of cells. These methods require relatively large numbers of cells, and do not provide optimal resolution of the transitions between cell cycle phases. In this report we describe in detail complementary methods that utilize the incorporation of nucleotide analogs combined with microscopic examination. While often more time consuming, these protocols typically require far fewer cells, and allow accurate kinetic assessment of cell cycle progression. We also describe the use of a technique for the synchronization of adherent cells in mitosis by simple mechanical agitation (mitotic shake-off) that eliminates physiological perturbation associated with drug treatments.
Modeling the parasitic chemical reactions of AlGaN organometallic vapor-phase epitaxy

Abstract Growth rates for organometallic vapor-phase epitaxy of GaN and AlGaN were measured over a wide range of reactor conditions. Non-ideality in growth rates and alloy composition are clear indications of parasitic chemical reactions. These parasitic reaction pathways lead to formation of gas-phase particulates, complicating control of growth and composition. This data set is used in conjunction with a reacting-flow model to try to understand the chemistry leading to particulate formation. We have developed a relatively simple, nine-step reaction mechanism describing the Ga-precursor decomposition, Al-adduct formation and methane elimination, particle nucleation, and particle growth in the AlGaN system. Reacting-flow simulations were used to predict film growth rates and are in good agreement with our rotating-disk reactor experiments.
Integrated, variable-reluctance magnetic minimotor

The use of lithography and electroplating to fabricate variable-reluctance, nearly planar, integrated minimotors with 6-mm-diameter rotors on silicon wafers is described. The motors consist of six electroplated Permalloy® horseshoe-shaped cores that surround the rotor. Copper coils are formed around each core. The Permalloy and copper electroplating baths, electroplating seed layers, and through-mask plating techniques are similar to those used to fabricate inductive thin-film heads. High-aspect-ratio optical lithography or X-ray lithography was used to form the various resist layers. The rotors were fabricated separately, released from the substrate, and then slipped onto the shaft, which was plated as part of the stator fabrication process. The fabrication processes for stator and rotor are described in this paper, and initial minimotor operation data are presented.
Mechanism and kinetics of the reaction of acrylic polyols with hexa (methoxymethyl) melamine

New procedures have been developed to study the mechanism and kinetics of the crosslinking of acrylic polyols with hexa (methoxymethyl) melamine. Both the rate of gel formation and alcohol release are found to be affected by the concentration and the nature of the catalyst and to be proportional to the hydrogen ion concentration. The rate of gel formation can be modeled by using the Miller and Macosko procedure with the input consisting of the polymer composition and the rate of release of reaction products. The correlation between calculated and experimentally determined quantity of gel formed is good when the reactions are slow, but becomes poor when gel formation is rapid, suggesting that the formation of large rings is favored by rapid reaction. The rate of gel formation shows much less variation among different polymer systems than does the rate of release of reaction products from the crosslinking reaction.
Tranylcypromine substituted cis -hydroxycyclobutylnaphthamides as potent and selective dopamine D3 receptor antagonists

We report a class of potent and selective dopamine D3 receptor antagonists based upon tranylcypromine. Although tranylcypromine has a low affinity for the rat D3 receptor (Ki = 12.8 μM), our efforts have yielded (1R,2S)-11 (CJ-1882), which has Ki values of 2.7 and 2.8 nM at the rat and human dopamine D3 receptors, respectively, and displays respective selectivities of >10000-fold and 223-fold over the rat and human D2 receptors. Evaluation in a β-arrestin functional assay showed that (1R,2S)-11 is a potent and competitive antagonist at the human D3 receptor.
Stratigraphic Control of Production from Jurassic Calcarenites, Red Rock Field, Webster Parish, Louisiana: ABSTRACT

ABSTRACT Although associated with structural reversal and closure against a post-Smackover fault, hydrocarbon accumulation at Red Rock field in the upper members of the Late Jurassic Smackover and Buckner Formations is controlled for the most part stratigraphically by non-deposition or complete cementation of the reservoir facies. Red Rock is unique among the shelf-slope fields of Arkansas and Louisiana in that calcarenites of these members are productive on the downthrown side of a major fault. Petrographic study reveals no significant difference between calcarenites in downthrown and upthrown wells, and production may be expected from other areas which are now downthrown if they were favorably situated during deposition and diagenesis of the reservoir facies. On the shelf slope, Smackover nonskeletal calcarenites were deposited as bars on shoals usually associated with slight structural uplift. Although Buckner calcarenites are similar to those of the Smackover, their geometry suggests a beach environment. A thick east-west bank of mixed facies was deposited regionally along the subsiding seaward edge of the shelf slope. Several transgressive units extend updip from this bank, and reservoir facies were deposited along the beaches, especially where high energy conditions persisted for considerable periods of time on positive features such as Red Rock. Between transgressions, lowering of sea level or lack of subsidence permitted southward progradation of evaporitic mudflats. Uplift of the continent caused seaward progradation of coarser clastics, and Buckner mudstone graded upward into nonmarine sandstone of the "P" tongue of the Schuler Formation. During deposition of the latter interval, maximum displacement occurred along a down-to-north fault.
Clinical efficacy of adenine arabinoside in therapy of cytomegalovirus infections in renal allograft recipients.

Three renal allograft recipients, two with cytomegalovirus pneumonia and one with cytomegalovirus retinitis, were treated with adenine arabinoside. The dose was 5-10 mg/kg per day administered for four to six days. There was no clinical improvement in any of the patients. One patient died from overwhelming interstitial viral pneumonia. Cytomegalovirus was readily isolated from two patients after therapy (autopsied lung of one and the saliva of the other). Suppression of viruria was observed and quantitated in one patient (104.0-102.5 50% tissue culture infective doses/0.2 ml). However, the suppression was transient, and viral titers returned to the levels before therapy within two months after completion of therapy. Treatment was stopped in two cases when hematologic toxicity (drop in hematocrit and platelet and leukocyte counts) was noted in the patients five days after initiation of therapy with adenine arabinoside. The drug appears to be ineffective and possibly toxic in immunosuppressed renal allograft recipients infected with cytomegalovirus.
Low speed mixed lubrication of bulk metal forming processes

A simple analysis for the lubrication of saw-tooth surfaces with longitudinal lay under conditions of high fractional contact area is developed. This is then coupled with Wilson and Sheu's asperity flattening model to treat the mixed lubrication of a bulk metal forming process (rolling). It is shown that, even under low speed conditions where the inlet zone does not generate significant hydrodynamic pressures, relatively high hydrodynamic pressures can be generated in the work zone. This explains the persistence of hydrodynamic effects noted in low speed experiments.
Low speed preparation of microsomes: A comparative study

Abstract Microsomal fractions were isolated from hepatic tissue, housefly abdomen and southern armyworm midgut, either by centrifugation of post-mitochondrial supernatant for 1 h at 105 000× g or by calcium sedimentation and low speed centrifugation. A comparison of the two methods of isolation were made on the basis of: NADPH oxidase activity, O -demethylation of p -nitroanisole, spectral parameters of cytochrome P-450, and integrity of ultrastructural constituents. The method of isolation did not effect these parameters appreciably for microsomes isolated from hepatic tissue. Calcium sedimentation of insect microsomes resulted in a reduction of enzyme activity and an apparent decrease in cytochrome P-450. Ultrastructural integrity did not appear to be influenced by the method of sedimentation.
Ultra Low Loss Ceramic Dielectrics

The object of this research was to develop ultra low loss ceramic dielectrics. The possible causes of the dielectric loss of ceramic bodies were first analyzed theoretically. Experimental bodies, designed on the basis of this analysis, provide for ultra low dielectric loss.
Bioactive electroconductive hydrogels: the effects of electropolymerization charge density on the storage stability of an enzyme-based biosensor.

Electrode-supported hydrogels were conferred with the biospecificity of enzymes during the process of electropolymerization to give rise to a class of bioactive, stimuli-responsive co-joined interpenetrating networks of inherently conductive polymers and highly hydrated hydrogels. Glucose responsive biotransducers were prepared by potentiostatic electropolymerization [750 mV vs. Ag/AgCl (3 M KCl)] of pyrrole at Poly(hydoxyethyl methacrylate)-based hydrogel-coated Pt micro-electrodes (Φ = 100 μm) from aqueous solutions of pyrrole and glucose oxidase (GOx; 0.4 M pyrrole, 1.0 mg/ml GOx) to 1.0 and 10.0 mC/cm2. Polypyrrole was them over-oxidized by cyclic voltammetry (0–1.2 V vs. Ag/AgCl, 40 cycles in PBKCl, pH = 7.0). Biotransducers were stored at 4 °C in PBKCl for up to 18 days. Amperometric dose–response at 0.4 V vs. Ag/AgCl followed by Lineweaver–Burk analysis produced enzyme kinetic parameters as a function of electropolymerization charge density and storage time. Apparent Michaelis constant (KMapp) increased from 18.6–152.0 mM (1.0 mC/cm2) and from 2.7–6.1 mM (10.0 mC/cm2). Biotransducer sensitivity increased to 21.2 nA/mM after 18 days and to 12.8 pA/mM after 10 days for the 1.0 and 10.0 mC/cm2 membranes, respectively. Maximum current, Imax, also increased over time to 2.7 nA (1.0 mC/cm2) and to 170 pA (10.0 mC/cm2). Electropolymerization of polypyrrole is shown to be an effective means for imparting bioactivity to a hydrogel-coated microelectrode. GOx was shown to be stabilized and to increase activity over time within the electroconductive hydrogel.
Dominant looking male teenagers copulate earlier

Abstract Many theorists suggest that dominant males leave more offspring than submissive males, but this seems not to be true among humans. Possibly dominant human males have more copulatory opportunity, but they or their partners prevent conception. Teenage boys were judged to look either dominant or submissive in facial appearance. They were also rated on attractiveness and pubertal development. Dominant looking boys are more likely to report coital opportunity than submissive looking boys, net of attractiveness and pubertal development.
Accommodation and Resistance: Latinas Struggle for Their Children's Education

Accommodation and resistance are not dichotomous phenomena but, rather, interwoven strategies for immigrants trying to survive in a cultural environment different from their own. Both strategies are responses to conflict, especially in the education of children. This article examines these conflicts among two generations of Latinas, and the ways in which they capitalized on their funds of knowledge to resolve conflicts. The issues involve not only differences in cultural practices and beliefs but also how these are shaped by participants' social positions and the institutional forces that threaten their beliefs.
On radii of neutron distributions in nuclei

Abstract We consider the analyses of the differences between rms radii (Δ = rn − rp) of neutron and proton distributions in a wide variety of nuclei. We note that apart from its own intrinsic interest, the quantity Δ is of importance for isotope shifts, core polarization contributions to the Coulomb energy differences of mirror pairs (Nolen-Schiffer anomaly) and the renormalization of the effective interaction. For example, if Δ were very small in 48Ca then the Nolen-Schiffer anomaly could be explained by a core polarization mechanism. We consider critically the various methods of determining Δ and conclude that at present probably the most reliable method is high energy (≈ 1 GeV) proton-nucleus scattering. The different theoretical analyses based upon, e.g., the multiple diffraction theory (where Glauber amplitude is the leading term) or the optical potential (KMT) formalisms appear to be converging to essentially the same answer when analyzing the same data. High energy α-particles and medium energy pions can also become useful sources of information if higher order optical potentials are treated with care. We find that Δ is rather large in 48Ca, i.e. there is a neutron skin, so that the Nolen-Schiffer anomaly cannot be explained by a core polarization mechanism. The results of high energy proton-nucleus scattering are in excellent agreement with current density dependent Hartree-Fock calculations.
Guest Editorial: Special Section on Contemporary and Emerging Issues in Physical Design

The eight papers in this special section highlight several studies on contemporary and emerging issues in physical design.
Convergence and synergy: Social Q&A meets virtual reference services

This paper presents a preliminary analysis of online information services that examines the intersection of two areas of research: Virtual Reference Services (VRS) and Social Q&A (SQA). This project embraces the idea of a synergic collaboration within and between VRS and SQA to provide higher quality content to information seekers and a higher level of sustainability. Preliminary findings are described that emanate from a grant-funded project: Cyber Synergy: Seeking Sustainability through Collaboration between Virtual Reference and Social Q&A Sites, which is being supported by the Institute for Museum and Library Services (IMLS). Early stages of the grant project activities include VRS transcript analysis and interviews with online Q&A end users (students) and experts (university librarians). Analysis reveals that VRS questions address a broad range of subjects, predominantly social sciences and technology. Largest numbers of question types are Procedural and Ready Reference. An analysis of accuracy for the subset of Ready Reference questions was found to be high, 90 percent correct, although only 75 percent were found to be correct with citation cited. Interviews with information seekers and providers in both VRS and SQA environments revealed important differences in how experts and end-users perceive online Q&A services, leaving clues as to how it may be possible to start bridging these systems.
A new approach for conjugate heat transfer problems using immersed boundary method for curvilinear grid based solvers

Abstract Use of immersed boundary method (IBM) based techniques have helped considerably in easing the grid generation process in flows involving complex geometries and/or large boundary movements. Body fitting grid based techniques still, however, are advantageous in terms of accuracy and efficiency. In this work, we have developed an IBM scheme applicable to curvilinear coordinates, aiming at taking advantage of both the methodologies. The framework uses efficient algorithms for search, locate, and interpolate operations. A new method of implementing the conjugate heat transfer (CHT) boundary condition is proposed which is a direct extension of the method used for other boundary conditions and does not involve any complex interpolations like previous CHT implementations using IBM. The developed scheme is shown to be applicable to complex geometries on curvilinear grids, while also being very efficient, consuming less than 1% of the total simulation time per time-step. Very good scalability on massive computations is demonstrated using strong scaling study up to 1024 cores. Detailed code verification process is undertaken to show that the method is second-order accurate for both the velocity and temperature fields for all the boundary conditions considered. Further, validation studies involving uniform flow over stationary and oscillating cylinders are carried out to demonstrate the accuracy of the developed method. Lastly, simulations are performed to study flow and conjugate heat transfer through thick-walled micro-channels using body-fitted background grids and the results are shown to be in excellent agreement with previously published results.
Regulation of Prohormone Convertases in Hypothalamic Neurons: Implications for ProThyrotropin-Releasing Hormone and Proopiomelanocortin

Recent evidence demonstrated that posttranslational processing of neuropeptides is critical in the pathogenesis of obesity. Leptin or other physiological changes affects the biosynthesis and processing of many peptides hormones as well as the regulation of the family of prohormone convertases responsible for the maturation of these hormones. Regulation of energy balance by leptin involves regulation of several proneuropeptides such as proTRH and proopiomelanocortin. These proneuropeptide precursors require for their maturation proteolytic cleavage by the prohormone convertases 1 and 2 (PC1/3 and PC2). Because biosynthesis of mature peptides in response to leptin requires prohormone processing, it is hypothesized that leptin might regulate hypothalamic PC1/3 and PC2 expression, ultimately leading to coordinated processing of prohormones into mature peptides. Leptin has been shown to increase PC1/3 and PC2 promoter activities, and starvation of rats, leading to low serum leptin levels, resulted in a decreas...
Extension of boundary relaxation for finite-difference solution of field problems

A method which reduces computer storage and time requirements for finite-difference solutions of field problems is described. Mesh points in regions away from complicated boundaries are eliminated, and in their place an analytic solution is used to formulate a new boundary condition close to the nonsimple regions.