cssi/SciSciGPT-SciSciNet huggingface dataset:
A multilayer hybrid-stress finite element analysis of a through-thickness edge crack in A ± 45° laminate

Abstract A solution is given for the three-dimensional stress field near a through-thickness edge crack in a thin ± 45° laminate having elastic ply moduli typical of graphite/epoxy. The stress distribution was obtained by a three-dimensional multilayer finite element analysis based on the hybrid stress model, formulated through the minimum complementary energy principle. The results indicate that the in-plane stresses of each individual ply follow the classical 1 √r stress singularity, but that the shape of isostress contours in the crack tip region is strongly distorted from predictions based on two-dimensional anisotropic fracture mechanics theory. The interlaminar shear stresses increase rapidly as the crack tip is approached, but are restricted to a local region around the crack tip and flanks. The interlaminar normal stress is assumed to be negligible in the formulation of the analysis.
Market Economy and Social Justice: The Predicament of the Underprivileged

Abstract As China's economic growth continues, more and more people in China have become affluent and have joined the middle-class ranks. At the same time, the gap between the rich and the poor is widening, so much so, that the gap may lead to social instability which may derail the economic development. The frequent mine explosions and the large number of deaths of mine workers, the irregular wage payment or non-payment to migrant workers, and the skyrocketing medical charges are just a few examples. Any society in transition experiences difficulties. The magnitude of the difficulty in China however is alarming. This paper attempts to examine the potential causes of the problems suffered by migrant workers, coal miners, and hospital patients and to discuss the consequences if those problems are not dealt with properly.
Lipid-lipid recognition in fluid bilayers: solving the cholesterol mystery.

Abstract Nearest-neighbour recognition measurements take ‘molecular-level snapshots’ of lipid organization in fluid bilayers by detecting and quantifying the thermodynamic tendency of two lipids to become nearest-neighbours. Recent nearest-neighbour recognition experiments have clarified the structural role that cholesterol plays in biological membranes. They have also clarified the influence that the linkage region of sphingolipids, the sugar head group of glycolipids, and lipid–peptide interactions have on lipid–lipid recognition.
STRATEGIC RESPONSES OF CHARTER AIRLINES TO SINGLE MARKET INTEGRATION

Abstract The charter airline industry has historically been regulated in a far more liberal fashion than the scheduled sector. The first two liberalization packages of the European Commission did not apply to charter operations, but the third package removed the regulatory distinction between the two modes. As a result of the establishment of the Single Market in air transport, charter carriers have ventured into the scheduled market and have developed new relationships with the major carriers. They have been cautious in taking advantage of the new freedoms afforded by the third package, but have adopted a variety of strategies to cope with the increasingly competitive air transport industry, including vertical and horizontal integration, product development and cost control.
Effect of stannous fluoride and sodium fluoride on hepatic mixed-function oxidase activities in the rat

Abstract Alterations in rat hepatic mixed-function oxidase activities were measured in vivo and in vitro 20 hr after pretreatment with a single dose of stannous fluoride or sodium fluoride. SnF 2 pretreatment significantly decreased the N-demethylation of aminopyrine and O -demethylation of p -nitroanisole; whereas, NaF in an equimolar dose did not affect N-demethylation but did decrease O -demethylation. Hexobarbital sleeping time was significantly prolonged by SnF 2 but not by NaF. Furthermore, the elimination half-life of antipyrine was increased by SnF 2 but not by NaF. These results demonstrate that the inhibition by SnF 2 of hepatic mixed-function oxidase activities in the rat is primarily due to the stannous ion and that fluoride ion has very little affect on these enzyme activities.
Ultrastructural changes accompanying secretion and cell death in the molting glands of an insect (Oncopeltus).

Abstract During the fifth (last) larval instar of Oncopeltus fasciatus , morphological changes in the molting glands associated with ecdysone secretion include an increase in cytoplasmic volume relative to that of the nucleus, increased amounts of rough endoplasmic reticulum and mitochondria, and the formation of deep infoldings of the plasma membrane. On the sixth day of the fifth instar large electron-lucent areas become apparent beneath the basement membrane; however, the glands remain intact until the seventh (last) day of the instar when a dramatic fragmentation of the cytoplasm, and condensation and fragmentation of the nucleus are observed. It is likely that such changes occur rapidly, just prior to the time of ecdysis to an adult. Cell death in the molting glands of Oncopeltus is markedly different from that described for the molting glands of other insect species in that autophagic vacuoles are not observed prior to a complete loss of cellular integrity.
BDNF Val66Met polymorphism and lithium response: a meta-analysis.

Aim: To characterize the impact of the Val66Met polymorphism on lithium response in patients with bipolar disorder. Methods: A systematic literature search of MEDLINE, Web of Science, PsychINFO and Cochrane CENTRAL was conducted from the earliest possible date through to 1 July 2012. The search was performed using the following medical subject headings: bipolar disorder, lithium, lithium carbonate, pharmacogenomics, pharmacogenetics, polymorphism and brain-derived neurotrophic factor. Five of 71 identified studies met the inclusion criteria. Data were abstracted using a standardized data abstraction tool. For categorical end points, the pooled odds ratio with 95% CI was calculated. Random effects models were used for analysis. Results: The Val66Met polymorphism did not predict response to prophylactic lithium in this combined population (odds ratio: 2.67; p = 0.078). Conclusion: This analysis suggests that the Val66Met polymorphism does not predict response to lithium treatment in bipolar disorder in this...
Electron microscopy of cardiolipin vesicles.

Cardiolipin, when placed in saline solutions, forms lamellar vesicles of varying complexity and size (600 A-3.0 μ ). When examined with high resolution electron microscopy, periodic structures consisting of alternating light and dark bands with a repeat distance of 50 A can sometimes be resolved. Upon sonication the vesicles break into smaller particles (250–1500 A) and appear generally as unilamellar structures. However, certain spherules can be found in which an apparently single lamella separated into two bands of less than 30 A thickness. These findings are interpreted in terms of a bimolecular lipid leaflet with osmium deposited in the hydrocarbon portion. In some cases electron dense material, presumably osmium precipitates, can be seen in an area between the two bands where they lie in close proximity to each other. The periodic structure observed in unsonicated preparations is thought to be the result of accumulation of relatively greater amounts of OsO 4 between bilayers of close proximity.
A Sociological Analysis of the Presidential Staff

All chief political executives face the management problem of controlling their subordinates in order to direct the activity of the state. The author argues that the presidential staff emerged in t...
New Technologies for Cervical Cancer Screening

New technologies for cervical cancer screening seek to provide an accurate, efficient and cost-effective way of identifying women at risk for cervical cancer. Current screening uses human papilloma virus DNA testing combined with cytology, and requires multiple visits at a great cost to the patient and society. New methods for screening include HPV diagnostics (detection of either the presence of human papilloma virus or integration of the virus into the host cell), proliferation, and detection of epigenetic changes, either in the host or virus. These methods show promise in changing the way that current cervical cancer screening is undertaken in low-and high-resource settings.
Holomorphic Idempotents and Retracts in the Unit Ball of a Commutative C*-Algebra with Identity

Let A be a commutative C*-algebra with identity and open unit ball B. We study holomorphic functions F: B → B that are idempotent under composition and establish necessary and sufficient conditions for a set R ⊆ B to be the image of B under such an idempotent function. (In other words, R is a holomorphic retract of B.) In order to achieve this result, a representation for linear idempotents of the algebra must be attained. The linear part of a holomorphic idempotent taking 0 to 0 is idempotent itself, and thus the linear representation can be used to prove several identities relating the linear and holomorphic idempotents, giving the main result.
Glucose-dependency of bradykinin-induced insulin secretion from the perfused rat pancreas

In order to investigate the glucose dependency of bradykinin (BK)-induced insulin secretion, rat pancreata were perfused in situ with BK (1 μM) for 30 min in the presence of glucose concentrations of 0–20 mM. Glucose (6 mM) alone maintained a steady baseline insulin secretion which was 6.7±0.5 ng/min (n=4). The rate of insulin secretion in the presence of 0 and 1 mM glucose was ∼70–80% and ∼60–70% less, respectively, than in the presence of 6 mM glucose. The perfusate glucose concentrations of 10 and 20 mM induced a biphasic and dose-dependent insulin secretion, characterized by a transient increase followed by a sustained phase; the sustained phase was higher than the transient increase. BK failed to change insulin secretion in the absence of extracellular glucose. When BK was administered in 1 mM glucose, it induced a transient insulin release peak which was 2.8-fold of the insulin secretion induced by 6 mM glucose, then the insulin concentrations of the effluents decreased gradually to the levels that were slightly higher than that induced by the 1 mM glucose alone, but lower than that induced by 6 mM glucose. After BK was administered in 6 mM glucose, it induced a transient insulin release peak that was 3.6-fold of the baseline level, and followed by a sustained insulin secretion phase which was ∼50% higher than that of the 6 mM glucose control group. When BK was perfused with 10 or 20 mM glucose, it induced a similar insulin secretion pattern as in the glucose alone groups. However, the combination of glucose (10 or 20 mM) and BK induced a higher transient insulin release peak, which was 7.8- and 12-fold of the baseline level, respectively. Also, the BK-glucose-induced sustained phase was higher than the transient peak. BK caused a greater potentiation of insulin secretion in 20 mM glucose than in 10 mM glucose. Taken together, our findings suggest that 1) BK requires the presence of glucose to stimulate insulin secretion and 2) BK induces insulin secretion in a glucose concentration-dependent manner; the higher the glucose concentration, the greater the potentiation in BK-induced insulin secretion.
Unit Characteristics and Patient Satisfaction A Multilevel Model

The purpose of this study was to discover if there was relationship between nurse perception of autonomy, control over practice, or relationships with physicians and patient satisfaction with care related to pain management, teaching, or physical care on medical surgical units. The study design was correlational, descriptive, and cross-sectional. The hospital sample was a purposive convenience sample of acute care hospitals in California, with a total of 21 hospitals, 60 medical surgical nursing units, 314 nurses, and 470 patients. Findings indicated that higher patient functional status and having a doctor in the hospital 24 hours/day were related to patient satisfaction with pain management. Lower nurse perception of autonomy, having a doctor in the hospital 24 hours/day, and higher number of patient years of education were related to higher patient satisfaction with teaching. Lower total hours worked by the nurses was related to higher patient satisfaction with physical care.
Argatroban in thrombotic stroke.

Evidence for the potential use of direct thrombin inhibition in the treatment of acute stroke is reviewed. Reduction of secondary microthrombi and improved regional collateral cerebral blood flow is the proposed mechanism of action of thrombin inhibition for the treatment of cerebral ischemia. A clinical study in Japan found that argatroban administered within 48 h of stroke symptom onset is safe and effective in reducing neurological impairment due to ischemic stroke. The implications of further clinical studies are discussed.
Effects of North Carolina's mandatory safety belt law on children.

OBJECTIVES: To assess the effect of the North Carolina law mandating that all front seat passengers use a safety belt on children 4 through 15 years of age. METHODS: North Carolina collision reports, completed by local police or the state highway patrol for crashes with greater than $500 worth of damage, were analyzed using time series analysis on the monthly percentage of deaths and serious injuries between January of 1980 and February of 1994. RESULTS: Following the 1985 implementation of the law, children 4 to 15 years of age experienced a 42% decline in deaths and serious injuries. CONCLUSIONS: The mandatory safety belt law in North Carolina has been associated with a decline in deaths and serious injuries. Additional research in needed to assess the seat belt behaviors of this age group as well as the specific effects of seat belt use using outcome measures more precise than those available in police crash reports.
Where in the World do Children Learn 'Bloody Revenge'?: Cults of terror and counter-terror and their implications for child socialisation

This paper elaborates some of the critical dimensions for understanding the emergence and maintenance of conflict-based solidarities worldwide and their implications for child and youth socialisation for violence and aggression. The paper in particular addresses some of the ways in which we might understand the global/local dynamics influencing the ways and degrees to which children around the world learn bloody revenge. The author proposes that the global-local dimensions of learning bloody revenge require that we understand the following: (1) the role that culture and psychology play in learning bloody revenge; (2) the ways in which the socialisation context created by terror makes making up so hard to do; and (3) the persistent and global link between all forms of violence and prevailing conceptions of masculinity. The author draws upon US responses to the September 11, 2001 attack on the World Trade Center to illustrate some key propositions.
Ground surface deformation patterns, magma supply, and magma storage at Okmok volcano, Alaska, from InSAR analysis: 2. Coeruptive deflation, July–August 2008

[1] A hydrovolcanic eruption near Cone D on the floor of Okmok caldera, Alaska, began on 12 July 2008 and continued until late August 2008. The eruption was preceded by inflation of a magma reservoir located beneath the center of the caldera and ∼3 km below sea level (bsl), which began immediately after Okmok's previous eruption in 1997. In this paper we use data from several radar satellites and advanced interferometric synthetic aperture radar (InSAR) techniques to produce a suite of 2008 coeruption deformation maps. Most of the surface deformation that occurred during the eruption is explained by deflation of a Mogi-type source located beneath the center of the caldera and 2–3 km bsl, i.e., essentially the same source that inflated prior to the eruption. During the eruption the reservoir deflated at a rate that decreased exponentially with time with a 1/e time constant of ∼13 days. We envision a sponge-like network of interconnected fractures and melt bodies that in aggregate constitute a complex magma storage zone beneath Okmok caldera. The rate at which the reservoir deflates during an eruption may be controlled by the diminishing pressure difference between the reservoir and surface. A similar mechanism might explain the tendency for reservoir inflation to slow as an eruption approaches until the pressure difference between a deep magma production zone and the reservoir is great enough to drive an intrusion or eruption along the caldera ring-fracture system.
An indirect immunofluorescence study of the distribution of fibronectin during the formation of the cushion tissue mesenchyme in the embryonic heart

Indirect immunofluorescence studies have localized fibronectin (FN) within the trunco-conal ridges of the chick embryo heart during the formation of the cushion tissue mesenchyme. Prior to cell migration into the endocardial pads, fluorescence for FN is demonstrated almost entirely in association with the basal surfaces of endocardium and myocardium. Scattered spots and thin dotted-strands of fluorescent material can be demonstrated in the cardiac jelly. Cushion tissue (CT) cells migrating into the cardiac jelly have patches of fluorescent material associated with their surfaces. Filopodial processes always show intense fluorescence. The close association between the fluorescence and the surface of the CT cells suggests that FN may be implicated in the interaction of these cells with the matrical components of the cardiac jelly and, therefore, in the process of cell migration into the endocardial pads. The intensity and amount of FN staining decreased concomitantly with the progressive accumulation of cells in the cushion areas. After the completion of CT cell migration only reduced amounts of faint fluorescence remained in the endocardial pad areas. The possible significance of the changes observed in the distribution of FN during the formation of the cushion tissue mesenchyme is discussed.
Ion flotation of cadmium using ethylhexadecyldimethylammonium bromide

Abstract Cadmium ions react with the collector, ethylhexadecyldimethylammonium bromide (EHDABr), to form a surface-active sublate which can be removed from aqueous bromide a . Effect of Foreign Metal Ions on the Flotation of Cadmium a Foreign ion Foreign ion concentration (M) (×10−5) Foreign ion removed (%) Cadmium removed (%) None 99.21 Zn2+ 6.11 0.06 98.41 Cu2+ 6.29 3.64 97.80 Pb2+ 3.86 4.80 91.78 Cr6+ 7.69 30.75 99.07 solutions by ion flotation. A typical ion flotation procedure involves passing air through a 250-ml solution containing 5 ppm Cd2+, 0.05 M Br−1, and 1.7 × l0−3 M EHDABr at a flow rate of 40 ml/min for 1 hr. The procedure was simple and efficient. Chromium, copper, and zinc ions do not interfere under the experimental conditions. a Cd2+, 4.46 × 10−5 M; EHDABr, 4.25 × 10−4; Br−, 5 × 10−2 M; flow rate, 40 ml/min; time, 60 min.
A review of candidate multilayer insulation systems for potential use on wet-launched LH2 tankage for the space exploration initiative lunar missions

The storage of cryogenic propellants such as liquid hydrogen (LH2) and liquid oxygen (LO2) for the future Space Exploration Initiative (SEI) will require lightweight, high performance thermal protection systems (TPS's). For the near-term lunar missions, the major weight element for most of the TPS's will be multilayer insulation (MLI) and/or the special structures/systems required to accommodate the MLI. Methods of applying MLI to LH2 tankage to avoid condensation or freezing of condensible gases such as nitrogen or oxygen while in the atmosphere are discussed. Because relatively thick layers of MLI will be required for storage times of a month or more, the transient performance from ground-hold to space-hold of the systems will become important in optimizing the TPS's for many of the missions. The ground-hold performance of several candidate systems are given as well as a qualitative assessment of the transient performance effects.
Random points on spheres: a graphics conjecture "proved"

Alan Schoen, a graphics expert at Southern Illinois University at Carbondale, has observed that the following result is true empirically:If 4 points are selected randomly on the unit sphere in Euclidean 3 space, then the probability that the tetrahedron with these points as vertices contains the origin is 1/23.
Investigation of Low Velocity Impact Damage in Aluminum Alloys

In structural health monitoring (SHM), impact detection and characterization techniques often focus on identifying parameters of impact such as the location and velocity of an impacting object. A distributed network of sensors is used to passively detect the mechanical wave created by the impact. Various techniques are used to analyze the signals based on time of arrival, amplitude and phase. A simpler architecture could be used to determine whether an impacting event was benign or caused damage and requires further evaluation. This research focuses on detecting attributes of impact-generated elastic wave signals that are indicative of local damage at the impact site. Waveforms deviate insignificantly for undamaged materials, however, when a material is stressed to plastic deformation or damaged the waveform of propagation through the material is noticeably affected. This change in wave speed may be detectable by SHM sensors, and can be used as an indicator of damage. Low velocity impact experiments were conducted on thin aluminum plates instrumented with piezoelectric and magneto-elastic sensors at various locations. The sensors acquired the initial passage of the impact wave signal before reflections off the boundaries became a significant element. By inspecting the signal for deviations induced by damage (such as plastic deformation), a routine for evaluating damage can be inferred. Further work may correlate features of the signal with damage severity providing an extra level of information in determining the next step in evaluating the damage. Using this approach, it may be possible to evaluate impact damage using limited numbers of passive sensors.Copyright © 2012 by ASME
Miscibility windows for poly(styrene-co-vinyl phenol) blends with poly(n-butyl methacrylate) and poly(n-hexyl methacrylate): a comparison of theoretical predictions with Fourier transform infra-red experimental data

Abstract Employing parameters recently derived from studies of miscible poly(4-vinyl phenol) (PVPh) blends with poly(ethyl methacrylate) and poly(n-propyl methacrylate), spinodal phase diagrams and ‘miscibility windows’ have been calculated for blends of styrene- co -vinyl phenol (STVPh) copolymers with poly(n-butyl methacrylate) (PBMA) and poly(n-hexyl methacrylate) (PHMA) using an association model. Theoretical calculations predict that STVPh copolymers containing 0-∼97% styrene are miscible with PBMA at ambient temperature. In contrast, PVPh is immiscible with PHMA at ambient temperature, but a miscibility window extending from ∼32–94% styrene was predicted. Five random copolymers of STVPh were synthesized containing 75, 43, 25, 8 and 2 wt% vinyl phenol (VPh) and experimental studies were performed on blends of these copolymers with PBMA and PHMA. Quantitative analyses of the fraction of hydrogen-bonded carbonyl groups were obtained by Fourier transform infra-red spectroscopy and the data compared to the theoretical predicted values for miscible systems. In addition, the hydroxyl stretching region of the spectrum was compared qualitatively to the theoretical distribution of hydroxyl-hydroxyl, hydroxyl-carbonyl and ‘free’ hydroxyl groups that would be present in a miscible blend. PVPh and the STVPh copolymers containing 75, 43, 25 and 8 wt% VPh were found to be miscible with PBMA, while the corresponding copolymer containing 2 wt% VPh was found to be immiscible. For the PHMA blends, PVPh and the two STVPh copolymers containing 75 and 2 wt% VPh were found to be immiscible with PHMA, while the corresponding copolymers containing 43, 25 and 8 wt% VPh were found to be miscible. These experimental results are in excellent accord with the theoretical predictions and lend support to the general validity of our association model approach.
Fascicular blocks: not interpretable from the electrocardiogram.

I ntroduction of the concept of hemiblock of the left bundle branch system’ (less erroneously termed “fascicular block”) was a pioneering effort that enabled electrocardiographers to think clinically in terms of the pathophysiology of conduction system lesions. Few would dispute that blocks can exist in particular parts of the conduction system, with or without accompanying myocardial lesions. However, it is questionable that one can securely deduce from the ordinary electrocardiogram the presence of such specific forms of interrupted conduction and highly questionable that their anatomic locations can be predicted. Much evidence now exists that the left bundle system only rarely approaches being biiascicular2~3 (negating any idea of hemiblock, which implies a bifascicular system); although an effective septal ramus can be demonstrated,4 even a trifascicular system remains too simplistic when d&sections of the left bundle system consistently show broader and narrower portions connected by loops and bridges, almost always among an assortment of fan-like smaller fascicles.2-5 These complex arrangements are further confounded by great intersubject variability.2,4 Moreover, tine dissection limited to the left bundle conducting system in patients whose electrocardiograms show either leftor right-axis deviation necessary to even consider a fascicular block from the electrocardiogram disclose a plethora of lesions, most quite proximal to the proposed anterior and posterior major fasci~les.**~ Furthermore, many patients with appropriate axis deviations have additional or isolated lesions of the myocardium both adjacent to and remote from the bundle system.4Jj Long ago, for example, Grant6 showed that a myocardial lesion in an appropriate location could slow intramyocardiil conduction so that the terminal portion of the QRS would be generated in such slowed areas, skewing the net QRS vector toward them. Thus, an. anterolateral infarct, for example, would tend to generate a left-axis deviation on this basis with or without involvement of the conducting system. Reeent eAeneer Phase analysis using a variety of approaches-is has found wide clinical and investigative application, primarily as a method for evaluating ventricular regional wall motion abnormalities in the diagnosis of ischemic heart disease. New evidence bearing on putative fascicular block has appeared using phase image characterization of ventricular contraction in patients with a range of left-axis deviation and left-axis deviation combined with right bundle branch block.”
Stress intensity factors for cracks emanating from rectangular cutouts

The stress intensity factors are determined at the crack roots for a rectangular cutout with symmetric edge cracks in an infinite sheet under uniaxial tension.
Identification of Gifted African American Primary Grade Students through Leadership, Creativity, and Academic Performance in Curriculum Material Making and Peer-Teaching: A Case Study

Research into identification of gifted early childhood students of minority groups through classroom activities is lacking. A focus in the United States on students with learning challenges and a lack of awareness of educators concerning the needs of early childhood gifted students are important causes of this situation. The current case study investigated whether African American students not identified through standard achievement scores might be recognized as gifted through performance during and after a special enrichment project. Eight (four female, four male; five White, three African American) identified or potentially gifted first/second grade students from a multi-age, mixed ability, diverse classroom at an elementary school in Iowa, participated in a 12-week enrichment program to develop leadership through curriculum material making and peer teaching. School and university personnel collaborated to meet school needs: supplying challenging activities to high achievers, offering the opportunity for leadership through peer-teaching, and providing alternate means (leadership, creativity) of potentially identifying typically-achieving minority students as gifted. A pre-post class sociogram was administered to all students in the broader class (11 female 8 male). The teacher observed evidence that all participating students gained confidence and leadership skills; two of the three African American students were identified as gifted through their leadership, creativity, and academic performance during the project. Curriculum materials-making projects with integrated thinking skills like those in the current study were enriching for all participants in the current study, including classmates who were peer-taught; similar enrichment activities are recommended for primary grade students.
Human prostate epithelial cell model system for carcinogenic studies

The immortal human prostate cell line, 267B1, has been used as a model system for investigating molecular events in carcinogenesis. Exposure of these cells to ionizing radiation results in progression to anchorage-independent growth. In addition, transfection of 267B1 cells with the activated Ki-ras oncogene results in tumorigenicity. We present here the further characterization of these cells, observing that both the immortalized 267B1 cell line and irradiated clones contain the wild type Ki-ras-2 gene and a Ki-ras pseudogene (Ki-ras-1 like). No mutations in p53 were observed. Cells expressing anchorage-independent growth following x-ray irradiation exhibited loss or rearrangements in numerous chromosomes, including chromosomes 10 and 18. These data are important for investigators using this model cell system for studies of carcinogenesis, gene expression, and signal transduction. © 1995 Wiley-Liss, Inc.
High-performance silica nanoparticle reinforced poly (vinyl alcohol) as templates for bioactive nanocomposites.

Abstract Silica nanoparticle reinforced poly (vinyl alcohol) cast sheets 40 μm thick were tested for mechanical and biological properties. The films were characterized using X-ray diffraction, scanning electron microscopy, and infrared spectroscopy. The crystallinity decreased with increased silica content. Changes in the morphology and structure upon the addition of silica suggest the formation of cross-linking. The modulus increased from 300 MPa for PVA to 7.2 GPa for 120 wt.% silica nanoparticle in the blend and the tensile strength increased from 3.5 MPa to 35 MPa. The modulus estimated using dynamic tests, tensile tests, and nanoindentation was comparable and was predicted well using the Halpin-Tsai's equation. The nanocomposites were an order of magnitude tougher than the pure polymer. Silica based nanocomposite was also found to be an excellent template for the deposition of calcium hydroxyapatite when immersed in simulated body fluid. The modulus and tensile strength of apatite coated silica nanoparticle (120 wt.%)–PVA composite increased to 11 GPa and 65 MPa respectively, close to that of cortical bone. The results represent one of the largest increases in mechanical properties of nanocomposite mimicking the properties of human bone. The addition of silica can also aid in osseointegration.
Elemental Analysis Using Microwave Digestion and an Environmental Evaporation Chamber

A major concern in laboratories performing trace element determinations is sample contamination. Sensitivity can be enhanced for trace elements by using larger samples, but this approach may increase the risk of contamination due to the need for more involved preparation techniques. With the isolation of the sample from the laboratory environment, the potential for contamination is greatly reduced during sample decomposition. In this investigation, an environmental evaporation chamber (EEC) placed in a microwave digestion system was used for predigestion of biological and botanical samples prior to closed-vessel digestion. The EEC was also used for the evaporation of residual acid after completion of the digestion procedure. Data are presented for the analysis of standard reference materials along with detection limits and the results of a crosscontamination study for the described method.
Suppression of cyclic AMP-dependent protein kinase activity in murine melanoma cells by 12-0-tetradecanoylphorbol-13-acetate

Abstract The effect of the potent tumor promoter 12-0-tetradeconylphorbol-13-acetate (TPA) on the cyclic AMP metabolism of B16 mouse melanoma cells was examined. TPA (10−7M) slightly increased the growth rate and inhibited melanin production by these cells. Although TPA had little effect on basal or hormone stimulated cyclic AMP levels, it did significantly suppress cyclic AMP-dependent protein kinase activity from treated cells in a dose-dependent fashion. Other phorbol ester and non-phorbol ester tumor promoters also suppressed cyclic AMP-dependent protein kinase activity while the non-promoter, phorbol, did not alter cyclic AMP-dependent protein kinase activity.
Inappropriate Vancomycin Prescribing Based on Criteria from the Centers for Disease Control and Prevention

Increasing reports of vancomycin resistance have raised concerns about the future effectiveness of this drug in treatment of critically ill patients with gram-positive infections. Due to these concerns the Centers for Disease Control and Prevention (CDC) recently published criteria that delineate the prudent use of vancomycin. Using these criteria, we attempted to determine the appropriateness of vancomycin prescribing patterns at our institution. A retrospective chart review was performed for 135 hospitalized patients treated between May 1993 and April 1994. Inappropriate empiric vancomycin use was documented in 81 (60%) of these patients. When culture results were available, 28 (21%) patients inappropriately received the drug. Results of this study are similar to those of other studies of vancomycin use in hospitals based on non-CDC criteria. If CDC criteria are to have a positive impact on physicians' vancomycin prescribing patterns, significant educational efforts will be required.
Predicting embolic potential during carotid angioplasty and stenting: analysis of captured particulate debris, ultrasound characteristics, and prior carotid endarterectomy.

Introduction Extracranial carotid stenoses exhibit significant variance in embolic potential, with restenotic lesions having a particularly low propensity for embolization. This study sought to identify characteristics associated with increased generation of embolic debris during carotid angioplasty and stenting (CAS). Methods Captured particulate was available for analysis in 56 consecutive patients. Demographics were mean age, 74 years (range, 60-94 years); mean stenosis, 88% (range, 70%-99%); symptomatic, 27%; prior carotid endarterectomy (CEA), 27%; prior radiotherapy, 7%. Plaque echogenicity, heterogenicity, ulceration, and irregularity were assessed with B-mode duplex ultrasound analysis. Gray scale median (GSM) was calculated from normalized B-mode VHS video recordings. Calcification and degree of stenosis were determined angiographically. Captured particulate debris was evaluated for total number; number >200 μm, >500 μm, >1000 μm; mean and median size. Hematoxylin and eosin, trichrome, and von Kossa stains were used for histologic analysis of captured material. Results Restenotic carotid stenoses after prior CEA generated minimal embolic debris compared with primary stenoses. Four of 15 patients (27%) with restenotic lesions demonstrated embolic particles; all debris was 200 μm in 91%, >500 μm in 72%, and >1000 μm in 43%. In primary lesions, the number and size of captured particulate correlated with GSM and with the combined ultrasound findings of echogenicity, heterogenicity, and luminal irregularity/ulceration ( P P = NS). Patients aged >70 years exhibited more total particles (8.1 vs 2.3, P = .008) and increased mean particle size (370 vs 157 μm, P = .02). No significant correlation was observed between the number and size of captured embolic particulate and any other variable (stenosis percentage, prior radiotherapy, preprocedural symptoms, periprocedural symptoms, and calcification). Histologically, the embolic debris consisted of extensive amorphous, acellular proteinaceous material. Calcium debris in the embolic particulate was associated with heavily and moderately calcified lesions. Conclusions Considerable variation exists in the number and size of embolic particles generated during CAS. Embolic potential is positively correlated with lesion GSM and the combination of lesion echogenicity, heterogenicity, and irregularity. Restenosis after prior CEA is associated with minimal embolic particulate generation, suggesting that embolic protection may not be necessary for CAS of restenotic lesions.
Central program for scratch reflex in turtle

1. A scratch reflex is displayed by a low spinal turtle in response to gentle mechanical stimulation delivered to specific regions of the shell anterior to a hindlimb (Valk-Fai and Crowe, 1978, 1979). The behavior consists of a rhythmic limb movement in which the foot protracts and rubs against the stimulated patch of shell once per cycle. A brief stimulus can elicit a response composed of a small number of cycles or even a fraction of a cycle (Fig. 1); maintained rubbing of the shell can elicit a response consisting of 5–20 cycles (Fig. 2A). 2. The scratch motor program is divisible into an A phase in which IT-KE is active and a B phase in which IT-KE is quiescent and HR-KF is active (Fig. 2B). The A phase is further divisible into an A1 phase in which IT-KE is the only active KE muscle and into an A2 phase in which all three KE muscles are active. 3. Two variations of the scratch program exist (Figs. 3 and 4). These variations indicate that there are flexibilities in the organization of the spinal generator for turtle scratch reflex. 4. The scratch motor program can also be expressed in a preparation immobilized by a neuromuscular blocking agent (Figs. 5 and 6). The responses in this preparation are termed the fictive scratch reflex since they occur in the absence of a real movement. One of the variations in the scratch program which was seen in preparations with a moving limb was also seen in the fictive scratch reflex (Fig. 7). 5. The scratch motor program can also be expressed in preparations with the hindlimb enlargement deafferented via bilateral dorsal rhizotomies (Figs. 8 and 9). 6. These observations establish that the turtle scratch reflex is centrally programmed, i.e., it is not dependent upon phasic timing cues derived from sensory feedback. Even though the reflex is centrally programmed, it is still possible to demonstrate that sensory feedback from a moving limb can modulate the scratch rhythm (Fig. 10 of this paper and Fig. 6 of Valk-Fai and Crowe, 1979).
Iron(III)-siderophore coordination chemistry: Reactivity of marine siderophores

Two remarkable features of many siderophores produced by oceanic bacteria are the prevalence of an α-hydroxy-carboxylic acid functionality either in the form of the amino acid β-hydroxy aspartic acid or in the form of citric acid, as well as the predominance of amphiphilic siderophores. This review will provide an overview of the photoreactivity that takes place when siderophores containing β-hydroxy aspartic acid and citric acid are coordinated to iron(III). This photoreactivity raises questions about the role of this photochemistry in microbial iron acquisition as well as upper-ocean iron cycling. The self-assembly of amphiphilic siderophores and the coordination-induced phase-change of the micelle-to-vesicle transformation will also be reviewed. The distinctive photosensitive and self-assembly properties of marine siderophores hint at possibly new microbial iron acquisition mechanisms.
Variability in the deep and intermediate water circulation of the Atlantic Ocean during the past 25,000 years: Northern Hemisphere modulation of the Southern Ocean

The relative flux of North Atlantic Deep Water (NADW) out of the Atlantic can be monitored in the Southern Ocean, where high δ13C NADW mixes rapidly with low δ13C recirculated Pacific water before forming Antarctic Bottom Water (AABW). By using δ13C measured in benthic foraminifera as a water mass tracer, it is shown that the Southern Ocean was dominated by Pacific water, with little NADW contribution during the last glaciation. These tracer results document the direct physical connection between insolation controlled Northern Hemisphere oscillations and changes in the chemical and physical properties of Southern Ocean water. The δ13C records from the deep tropical Atlantic document the transition from an Atlantic dominated by Southern Ocean water during the last glaciation to an Atlantic dominated by NADW during the Holocene. With more Southern Ocean water in the deep Atlantic during the last glaciation, the boundary between NADW and Southern Ocean water was north of its modern position, allowing more Southern Ocean water to enter the eastern Atlantic through the Romanche Fracture Zone. Carbon isotope records from the Caribbean and Mediterranean Seas suggest that the influence of Mediterranean Overflow Water (MOW) extended to the Caribbean during the last glaciation, and therefore was a volumetrically much more important water mass in the intermediate-depth Atlantic than it is today.
Northwestern European Paleogene magnetostratigraphy, biostratigraphy, and paleogeography: Calcareous nannofossil evidence

Global calcareous nannofossil biostratigraphy is used to correlate the Paleogene chronostratigraphic units of northwestern Europe and standard nannofossil biozones. Such biostratigraphic correlations show that the lithostratigraphic sequence is discontinuous and allows interpretation of the paleogeography of northwestern Europe during the Paleogene and evaluation of the influence of global sea-level (eustatic) changes on northwestern European stratigraphy. A well-documented unconformity occurs near the lower/middle Eocene boundary in the Paris Basin. This unconformity, which also can be traced in the London-Hampshire Basin and in Belgium, correlates with a coastal offlap event (presumed sea level) of Vail et al. On the basis of magnetostratigraphic-biostratigraphic correlations, the duration of the hiatus associated with this unconformity can be estimated to be 0.6 to 1.5 m.y. in the Hampshire Basin and 2 to 4 m.y. in the Paris Basin.
Sentinel lymph node mapping of breast cancer via intradermal administration of Lymphoseek.

Abstract Lymphoseek is a molecular imaging agent specifically designed for sentinel lymph node (SLN) mapping. We conducted a Phase I trial which measured the injection site clearance and SLN accumulation after a single intra dermal injection of Lymphoseek or [ 99m Tc]sulfur colloid protocol. Ten patients with breast cancer participated in this study. Five patients received an intradermal administration of 1.0 nmol of 99m Tc-labeled Lymphoseek and five patients received an intradermal administration of filtered [ 99m Tc]sulfur colloid (fTcSC). Lymphoseek exhibited a significantly ( P P =.28). When an intra dermal injection was employed, Lymphoseek demonstrated faster injection site clearance than fTcSC.
Coherent-Potential Approximation for an n -Component Alloy and Localization of Electrons

It is shown that the ensemble-averaged single-particle Green's function for an electron in a disordered $n$-component alloy is described by a simple expression in the coherent-potential approximation. Within the appropriate limits, it exhibits dilute alloy, virtual crystal, weak-coupling limit, and atomic behaviors. For a special model band structure of parabolic form, the problem of evaluating the quasiparticle density of states is reduced to that of solving a polynomial of $n+1$ order, which has either $n+1$ real solutions or $n\ensuremath{-}1$ real solutions in addition to two complex-conjugate solutions for a given set of parameters. The types of the density of states \char22{} persistence or amalgamation \char22{} are judged by the types of solutions. The formulation is also useful to prove the sum rules for the numbers of states. In the limit of $n$ infinite, continuous distributions of atomic levels are studied and the criterion for the Anderson transition is estimated.
Development of highly robust nano-mixed Hf/sub x/Al/sub y/O/sub z/ dielectrics for TiN/Hf/sub x/Al/sub y/O/sub z//TiN capacitor applicable to 65nm generation DRAMs

TIT capacitor with Nano-mixed Hf/sub x/Al/sub y/O/sub z/ dielectric was successfully demonstrated to be applicable to 65nm DRAM devices. Nano-mixed Hf/sub x/Al/sub y/O/sub z/ thin film by ALD(Atomic Layer Deposition) showed an excellent thermal stability even up to 700/spl deg/C without any leakage current degradation. Moreover, Nano-mixed films revealed lower leakage current than laminate due to effective nano-scale mixing of HfO/sub 2/ and Al/sub 2/O/sub 3/TiN/Hf/sub x/Al/sub y/O/sub z//TiN capacitor turned out to be applicable to 65nm DRAM showing low EOT of 11/spl Aring/ and low leakage of 1 fA/cell.
Fatty acid binding to vesicular stomatitis virus glycoprotein: a new type of post-translational modification of the viral glycoprotein

Abstract The glycoprotein (G) of vesicular stomatitis virus (VSV) binds 1–2 moles of fatty acid per mole of protein. The fatty acids cannot be released by repeated extractions of the protein with organic solvents, nor can they be released by denaturing the protein with ionic or nonionic detergents. Pronase digestion of G yields an organic extractable fragment that contains bound fatty acid. The fatty acid is quantitatively released from this fragment and from intact G by mild alkali treatment in methanol and is identified by gas-liquid and thin-layer chromatography as, predominantly, the methyl ester of palmitic acid. Insignificant amounts of phosphate are found in G, thus ruling out the presence of bound phospholipid. Chicken embryo fibroblast pre-labeled with 3 H-palmitate and then infected with VSV for 4 hr show the presence of 3 H label in G but not in other viral structural proteins. The 3 H label is present only in the fatty acid moiety of the protein. Much smaller amounts of 3 H fatty acid are bound to G protein formed by the VSV mutant ts045 grown at the nonpermissive temperature, and no 3 H fatty acid is bound to G synthesized at 37°C in cells pretreated with tunicamycin, an inhibitor of glycosylation. However, infection with the VSV-Orsay strain at 30°C in the presence of tunicamycin allows for production of VSV particles with nonglycosylated G (Gibson, Schlesinger and Kornfeld, 1979), and this G has the same proportion of the fatty acid as does the normal glycosylated G. These data indicate that fatty acids become covalently attached to the G polypeptide chain during maturation of the protein—perhaps as the glycoprotein moves to the cell's plasma membrane.
An NMR Determination of CO Diffusion on Platinum Electrocatalysts

We report the first direct measurement of CO diffusion on nanoparticle Pt electrocatalysts at the solid/liquid interface, carried out using 13C nuclear magnetic resonance (NMR) with a spin-labeling pulse sequence. Diffusion parameters were measured in the temperature range of 253-293 K for CO adsorbed on commercial Pt-black under saturation coverage. 2H NMR of the same system indicates that the electrolyte remains in the liquid state at temperatures where the CO diffusion experiments were performed. The CO diffusion parameters follow typical Arrhenius behavior with an activation energy of 6.0 +/- 0.4 kcal/mol and a pre-exponential factor of (1.1 +/- 0.6) x 10-8 cm2/s. Exchange between different CO populations, driven by a chemical potential gradient, is suggested to be the main mechanism for CO diffusion. The presence of the electrolyte medium considerably slows down the diffusion of CO as compared to that seen on surfaces of bulk metals under UHV conditions. This work opens up a new approach to the study of surface diffusion of adsorbed molecules on nanoparticle electrode catalysts, including the possibility of correlating diffusion parameters to catalytic activity in real world applications of broad general interest.