cssi/SciSciGPT-SciSciNet huggingface dataset:
The Unravelling of Open-Ended Single Walled Carbon Nanotubes Using Molecular Dynamics Simulations

The unravelling of (10, 10) and (18, 0) single-walled carbon nanotubes (SWCNTs) is simulated using molecular dynamics simulations at different temperatures. Two different schemes are proposed to simulate the unravelling; completely restraining the last atom in the chain and only restraining it in the axial direction. The forces on the terminal atom in the unravelled chain in the axial and radial directions are reported till the separation of the atomic chain from the carbon nanotube structure. The force-displacement relation for a chain structure at different temperatures is calculated and is compared to the unravelling forces. The axial stresses in the body of the carbon nanotube are calculated and are compared to the failure stresses of that specific nanotube. Results show that the scheme used to unravel the nanotube and the temperature can only effect the duration needed before the separation of some or all of the atomic chain from the nanotube, but does not affect the unravelling forces. The separation of the atomic chain from the nanotube is mainly due to the impulsive excessive stresses in the chain due to the addition of a new atom and rarely due to the steady stresses in the chain. From the simulations, it is clear that the separation of the chain will eventually happen due to the closing structure occurring at the end of the nanotube that would not be possible in multiwalled nanotubes.
Rotational coherence effects in the femtosecond photodissociation of ICN

Abstract In this paper we use exact time-dependent quantum mechanical calculations to show that in the femtosecond dissociation of ICN both the translational and the rotational CN motion affect the LIF signal, and that they do so on different time scales.
Multiple splice variants of Par3 and of a novel related gene, Par3L, produce proteins with different binding properties ☆

Abstract The partitioning-defective 3 (par3) gene encodes a protein with three postsynaptic density90/DiscslargeA/ZO-1 (PDZ) domains that is required for cell polarity establishment in metazoans. Par3 is a component of a protein complex that can include Cdc42-GTP, Par6 and atypical protein kinase Cs (aPKCs). We now describe the identification of a related human gene, Par3L. Both Par3L and Par3 are expressed as numerous alternatively spliced variants. Although Par3 expression appears to be ubiquitous, that of Par3L is more restricted. Multiple variants are often expressed simultaneously within a specific cell type or tissue. Although all of the Par3L/Par3 isoforms can associate with tight junctions in epithelial cells, they show different binding properties. No Par3L isoforms and only a subset of Par3 isoforms detectably bind aPKCs. These data suggest that aPKC binding or phosphorylation is not required for targeting of Par3/Par3L to cell–cell contacts. Par3L isoforms also show differential binding to Par6. Despite these differences, the N-terminal region of Par3L, like that of Par3, can disrupt the formation of tight junctions when ectopically expressed in Madin–Darby canine kidney (MDCK) cells.
Chitaline materials: Soluble Chitosan-polyaniline copolymers and their conductive doped forms

Abstract Graft copolymers of polyaniline and chitosan have been synthesized. They are soluble in aqueous solution and form self-supporting materials, including thick films and fibers. Upon protonic doping, their conductivities rise from less than ∼10−7 S/cm to the 10−2 to 10−5 S/cm range, depending on the initial chitosan-to-aniline ratio. Spectroscopic studies show the grafting and demonstrate that the electronic states are similar to those of the emeraldine and protonically doped emeraldine forms of polyaniline.
Reactions of Vinyl Chloride and Methanol in a Quadrupole Ion Trap Mass Spectrometer during VOC Analysis

A reaction between vinyl chloride and the solvent (methanol) was observed during volatile organic compound (VOC) analysis on a gas chromatograph/quadrupole ion trap mass spectrometer (GC/MS). A chromatographic peak at a retention time consistent with vinyl chloride produced a mass spectrum without the characteristic chlorine isotope ions m/z 62 and 64 but instead contained an apparent molecular ion, m/z 58. The m/z 58 ion is not found in the reference spectrum of vinyl chloride. This spectrum was observed when methanol was used as solvent in internal standard, surrogate standard, or analyte solutions. Subsequent VOC standard analysis indicated that the abundance of the m/z 58 ion was directly proportional to the amount of vinyl chloride in the water samples. The correct spectrum for vinyl chloride was observed (m/z 62 and 64) when no methanol was added. From these experiments, we concluded that a reaction was occurring between the vinyl chloride and methanol in the ion trap producing a new species with a ...
Transient striatal GLT-1 blockade increases EAAC1 expression, glutamate reuptake, and decreases tyrosine hydroxylase phosphorylation at ser19

article i nfo Three glutamate transporters, GLT-1, GLAST, and EAAC1, are expressed in striatum. GLT-1 and, to a lesser ex- tent, GLAST are thought to play a primary role in glutamate reuptake and mitigate excitoxicity. Progressive tyrosine hydroxylase (TH) loss seen in Parkinson's disease (PD) is associated with increased extracellular glu- tamate. Glutamate receptor antagonists reduce nigrostriatal loss in PD models. These observations suggest that excess synaptic glutamate contributes to nigrostriatal neuron loss seen in PD. Decreased GLT-1 expres- sion occurs in neurodegenerative disease and PD models, suggesting decreased GLT-1-mediated glutamate reuptake contributes to excitotoxicity. To determine how transient GLT-1 blockade affects glutamate reup- take dynamics and a Ca 2+ -dependent process in nigrostriatal terminals, ser 19 phosphorylation of TH, the GLT-1 inhibitor dihydrokainic acid (DHK) was delivered unilaterally to striatum in vivo and glutamate reup- take was quantified ex vivo in crude synaptosomes 3 h later. Ca 2+ -influx is associated with excitotoxic con- ditions. The phosphorylation of TH at ser 19 is Ca 2+ -dependent, and a change resulting from GLT-1 blockade may signify the potential for excitotoxicity to nigrostriatal neurons. Synaptosomes from DHK infused stria- tum had a 43% increase in glutamate reuptake in conjunction with decreased ser 19 TH phosphorylation. Using a novel GLAST inhibitor and DHK, we determined that the GLAST-mediated component of increased glutamate reuptake increased 3-fold with no change in GLAST or GLT-1 protein expression. However, GLT- 1 blockade increased EAAC1 protein expression ~20%. Taken together, these results suggest that GLT-1 block- ade produces a transient increase in GLAST-mediated reuptake and EAAC1 expression coupled with reduced ser 19 TH phosphorylation. These responses could represent an endogenous defense against excitotoxicity to the nigrostriatal pathway.
Understanding Women's Underrepresentation in Science, Technology, Engineering, and Mathematics: The Role of Social Coping

Enrollment of women in science, technology, engineering, and mathematics (STEM) majors is disproportionately small and declining. This study examines social coping to explain the gender gap. Women undergraduates reported using significantly more social coping than did men. Multiple regression analyses revealed that social coping was a stronger predictor of commitment to major for women than for men. Social coping negatively predicted intent to turn over, or withdraw from, their major for women, but not for men. Unexpectedly, social coping negatively predicted academic course grade for men but not for women. Results suggest that women benefit more from social coping than do men. Implications for counselors and policy are discussed.
The electron density and temperature in the tail of comet Giacobini‐Zinner

The electron density and temperature profiles along the tail axis of Comet Giacabini-Zinner are calculated, using a multi-fluid model of an H2O-dominated atmosphere. The results obtained using this model, which was developed prior to ICE, are compared to the data from the mission and are found to be in satisfactory agreement with the ICE observations.
Adverse environmental conditions in the respiratory and medical ICU settings

Sleep deprivation and fragmentation occurring in the hospital setting may have a negative impact on the respiratory system by decreasing respiratory muscle function and ventilatory response to CO2. Sleep deprivation in a patient with respiratory failure may, therefore, impair recovery and weaning from mechanical ventilation. We postulate that light, sound, and interruption levels in a weaning unit are major factors resulting in sleep disorders and possibly circadian rhythm disruption. As an initial test of this hypothesis, we sampled interruption levels and continuously monitored light and sound levels for a minimum of seven consecutive days in a medical ICU, a multiple bed respiratory care unit (RCU) room, a single-bed RCU room, and a private room. Light levels in all areas maintained a day-night rhythm, with peak levels dependent on window orientation and shading. Peak sound levels were extremely high in all areas representing values significantly higher than those recommended by the Environmental Protection Agency as acceptable for a hospital environment. The number of sound peaks greater than 80 decibels, which may result in sleep arousals, was especially high in the intensive and respiratory care areas, but did show a day-night rhythm in all settings. Patient interruptions tended to be erratic, leaving little time for condensed sleep. We conclude that the potential for environmentally induced sleep disruption is high in all areas, but especially high in the intensive and respiratory care areas where the negative consequences may be the most severe.
Evaluation of scatter mitigation strategies for x-ray cone-beam CT: impact of scatter subtraction and anti-scatter grids on contrast-to-noise ratio

The large contribution of scatter to cone-beam computed tomography (CBCT) x-ray projections significantly degrades image quality, both through streaking and cupping artifacts and by loss of low contrast boundary detectability. The goal of this investigation is to compare the efficacy of three widely used scatter mitigation methods: subtractive scatter correction (SSC); anti-scatter grids (ASG); and beam modulating with bowtie filters; for improving signal-to-noise ratio (SNR), contrast, contrast-to-noise ratio (CNR) and cupping artifacts. A simple analytic model was developed to predict scatter-to-primary ratio (SPR) and CNR as a function of cylindrical phantom thickness. In addition, CBCT x-ray projections of a CatPhan QA phantom were measured, using a Varian CBCT imaging system, and computed, using an inhouse Monte Carlo photon-transport code to more realistically evaluate the impact of scatter mitigation techniques. Images formed with uncorrected sinograms acquired without ASGs and bow-tie filter show pronounced cupping artifacts and loss of contrast. Subtraction of measured scatter profiles restores image uniformity and CT number accuracy, but does not improve CNR, since the improvement in contrast almost exactly offset by the increase in relative x-ray noise. ASGs were found to modestly improve CNR (up to 20%, depending ASG primary transmission and selectivity) only in body scans, while they can reduce CNR for head phantoms where SPR is low.
Local actions for a curry-style operational semantics

Soundness proofs of program logics such as Hoare logics and type systems are often made easier by decorating the operational semantics with information that is useful in the proof. However, modifying the operational semantics to carry around such information can make it more difficult to show that the operational semantics corresponds to what actually occurs on a real machine.In this work we present a program logic framework targeting operational semantics in Curry-style---that is, operational semantics without proof decorations such as separation algebras, share models, and step indexes. Although we target Curry-style operational semantics, our framework permits local reasoning via the frame rule and retains expressive assertions in the program logic. Soundness of the program logic is derived mechanically from simple properties of primitive commands and expressions.We demonstrate our framework by deriving a separation logic for the model of a core imperative programming language with external function calls. We also apply our framework in a more realistic setting in the soundness proof of a separation logic for CompCert's Cminor. Our proofs are machine-checked in Coq.
A new (Hg, V)-based 1212-type cuprate (Hg, V) Sr2(Y, Ca) Cu2Oz with Tc(onset) up to 110 K

We have successfully synthesized a new (Hg, V)-based 1212-type cuprate (Hg1−xVx)Sr2(Y1−yCay)Cu2Oz. The electrical resistance measurements showed that some of the as-synthesized materials with proper Hg/V and Y/Ca ratios exhibit weak superconductivity. Oxygen-annealing significantly improved their superconducting behavior, andTc(onset) up to 110 K was observed. The lattice parameters of (Hg,V)-1212 were found to be in the order ofa=3.8415(1) A andc=11.8514(6) A. Substitu ting mercury atoms by vanadium ones results in an important increase of thea parameter and an important decrease of thec parameter compared to the known Hg-based Sr-bearing compounds. The crystal structure of (Hg, V)-1212 was refined by Rietveld refinement against X-ray powder data using the tetragonal symmetry of space groupP4/mmm. The V and Cu valence states and superconductivity in this new (Hg, V)-1212 cuprate are briefly discussed.
The implications of quality differences for United States and Canadian wheat trade

Abstract This paper endeavours to provide some insights as to why the USA, the fifth largest wheat producer in the world, imports a significant amount of wheat from Canada. After reviewing intra‐industry trade theory and the relevant empirical constructs, an implicit price function of the import demand for wheat focusing on the physical and intrinsic characteristics of wheat is estimated. The results are revealing. There is a premium for the protein content and the percentage of heat damaged kernels in wheat. Clearly, the fact that wheat is a differentiated commodity possessing a mix of physical and intrinsic characteristics together with price considerations helps to explain why the import of Canadian wheat by the USA happens and why this became a significant issue in 1993.
Low-Temperature Production of Ti-Al Alloys Using Ionic Liquid Electrolytes: Effect of Process Variables on Current Density, Current Efficiency, and Deposit Morphology

Application of novel low-temperature ionic liquid electrolytes for the extraction of Ti-Al alloys was investigated. The study was focused on the production of Ti-Al alloys from AlCl3-1-butyl-3-methyl imidazolium chloride (BmimCl) (molar ratio of AlCl3 and BmimCl is 2:1) at different temperatures between 70 °C and 125 °C ± 3 °C. The Ti-Al alloys were deposited on titanium sheet (>99.9 wt pct) cathodes at various voltages between 1.5 and 3.0 V. Titanium sheet was used as the anode and its dissolution served the source of Ti ion in the electrolyte. Morphology and composition of deposited Ti-Al alloys were investigated using a scanning electron microscope (SEM) with energy-dispersive spectroscopy (EDS) and an inductively coupled plasma–optical emission spectrometer (ICP-OES). The phase analysis was carried out using X-ray diffraction (XRD). This study was focused to determine the effect of process variables such as applied voltage and temperature on cathode current density, current efficiency, composition, and morphology of Ti-Al alloys. The Ti-Al alloys containing about 13 to 25 atom pct Ti were produced with a current efficiency of about 79 to 87 pct. This study shows that uniform and fine particle size with high titanium content Ti-Al alloy was obtained in the voltage range of 1.5 to 2.0 V and temperature between 70 °C to 100 °C.
Effect of Fluorescent Light on Amino Acid Composition of Serum Proteins from Homogenized Milk

Abstract The serum proteins isolated from homogenized milk by centrifugation and exposed to 2152 lx of fluorescent light for 72h were fractionated into the major protein components by gel filtration chromatography. Amino acid composition of the major serum proteins, β -lactoglobulin and α-lactalbumin which accounted for 80% of the total serum protein, did not change substantially following light exposure. Changes in amino acid composition associated with fluorescent light exposure occurred primarily in the high molecular weight fraction of serum proteins. This fraction amounts to at most 10% of the serum proteins.
High Power Silicon-Germanium Photodiodes for Microwave Photonic Applications

We demonstrate high current operation of an evanescently coupled Ge waveguide n-i-p photodetector grown on top of a Si rib waveguide. A 7.4 μm × 500 μm device was found to dissipate 1.003 W of power (125.49 mA at -8 V). 2-D thermal simulations of the device show that the relatively high thermal conductivities of the intrinsic Ge region and the p+ doped Si layer result in efficient heat transfer and hence, lower absorber temperatures when compared to a similar InP based waveguide photodiode. Additionally, to determine the feasibility of these devices for analog photonic applications, we performed large signal and small signal radio frequency (RF) measurements as well as linearity measurements. At 1 GHz and 40 mA of photocurrent, a third order output intercept point (OIP3) of 36.49 dBm is measured. The maximum RF power extracted at 1 GHz is 14.17 dBm at 60 mA of photocurrent and 7 V reverse bias.
Assessment of Women for Partner Abuse

Nearly 4 million women in the United States were physically hurt by their husbands or boyfriends in 1994. The health and well-being of these women and their children, as well as the women who are overlooked in these statistics, are jeopardized by past and current experiences with abuse within intimate relationships. Strategies for nurses in women's health care settings to screen women for current or past abuse within their intimate personal relationships, guidelines for effective responses to disclosure of abuse, and supportive interventions are described.
Human C3b- and C4b-regulatory proteins: a new multi-gene family

The complement cascade is regulated to prevent inappropriate activation. This regulation is targeted not only at the initiation of the cascade but also at the amplification andjunctional (C3) steps. Five glycoproteins with both complement regulatory activity and binding affinity for C3b/C4b have been characterized. In plasma these molecules are factor H(H) and C4-binding protein (C4-bp) and, on cells, they are the C3b/C4b receptor (CR1), decay-accelerating factor (DAF), and gp45-70. Here Michael Holers and his colleagues review structural, functional and genetic studies of these proteins and discuss the evidence for a new multi-gene family with a common ancestral protein.
Positive Social Alcohol Outcome Expectancies, Social Anxiety, and Hazardous Drinking in College Students

Although social anxiety and problematic alcohol use co-occur at alarmingly high rates, the mechanism for this co-occurrence is not well understood. The current study examined the mediating role of positive social alcohol expectancies (i.e., beliefs related to the desirable social effects of drinking) in the relationship between social anxiety and hazardous drinking (i.e., heavy drinking and negative consequences) among an ethnically and racially diverse (87% racial and/or ethnic minority) sample of undergraduate volunteers (n = 610; Mage = 19.1; 69% women). The results of structural equation modeling analyses (using AMOS 7.0) indicated that social (but not tension reduction, sexual enhancement, positive cognitive changes, or negative affective changes) alcohol outcome expectancies partially mediated the association between social anxiety and hazardous drinking; however, social anxiety had a negative direct effect on hazardous drinking. Findings implicate social alcohol outcome expectancies as a mechanism to target in treatment and prevention among socially anxious students.
Quantum probability distributions in the early Universe. III. A geometric representation of stochastic systems

We present a geometric interpretation of the dynamics of quantum stochastic systems obeying the Wigner equation. We apply this representation to the quantum fluctuations of the homogeneous long-range free scalar field in de Sitter space (m<, , , ...) space. Up to initial conditions, each trajectory uniquely characterizes the evolution of the system. The stationary states of the system act like fixed points or attractors in the moment space. We present the evolution of the scalar field as a flow in the moment space and show that the Bunch-Davies vacuum is the fixed point.
A randomized trial of tramadol versus ibuprofen as an adjunct to pain control during vacuum aspiration abortion

Abstract Background The study was conducted to determine whether tramadol is more effective than ibuprofen for reducing pain during uterine aspiration for abortion. Study Design Women presenting to a community-based abortion clinic were invited to participate in this double-blind, randomized trial. Following informed consent, subjects were randomly assigned to receive either 50 mg tramadol or 800 mg ibuprofen orally in addition to the standard clinic analgesic protocol. The primary outcome was pain as verbally rated on a scale from 0 to 10. Measurements were obtained immediately after and 30 min postprocedure. Results One hundred fifty-eight women were enrolled, 80 women were randomized to ibuprofen and 78 women, to tramadol. Immediately after the procedure, the mean pain scores in both treatment groups were 4.9 (95% CI=4.3–5.5). Thirty min postoperatively the mean pain score in the ibuprofen group was 2.8 compared to 3.6 in the tramadol group (p=.04). Conclusion There was no difference in immediate postprocedure pain between women receiving tramadol or ibuprofen. Ibuprofen is somewhat more effective than tramadol at reducing pain 30 min following surgical abortion.
Thrombin regulates monocyte chemoattractant protein-1 expression in human first trimester and term decidual cells

Objective Excess decidual macrophage infiltration has been linked to preeclampsia and a failure of endovascular trophoblast invasion. Severe preeclampsia with shallow placentation has also been linked to acquired and inherited maternal thrombophilias and recurrent decidual hemorrhage, which generates thrombin from decidual cell–expressed tissue factor. Therefore, the current study evaluated whether thrombin affects monocyte chemoattractant protein-1 (MCP-1) expression in stromal cells that are derived from cycling and gestational endometrium. Study Design Stromal cells that are isolated from cycling endometrium and first trimester and term decidua were grown to confluence, treated for 7 days with 10 −8 mol/L estradiol (E 2 ) + 10 −7 mol/L medroxyprogesterone acetate (MPA), then switched to a serum-free medium that contained the corresponding steroids ± thrombin. MCP-1 protein release was measured by enzyme-linked immunosorbent assay and Western blot; MCP-1 messenger RNA levels were assessed by real-time quantitative reverse transcription–polymerase chain reaction. Results Secreted MCP-1 levels were not significantly different in stromal or decidual cell cultures that were incubated with E 2 or with E 2 + MPA. Thrombin increased immunoreactive MCP-1 expression in a dose-response fashion in first trimester and term decidual cells but not in endometrial stromal cells. Thrombin-induced MCP-1 protein output was unaffected by MPA but was abrogated by incubation with the thrombin inhibitor, hirudin. Unexpectedly, thrombin-enhanced MCP-1 protein expression was unaccompanied by corresponding changes in steady state MCP-1 messenger RNA levels, which suggests its effects were posttranslational. Conclusion MCP-1 protein expression is up regulated by thrombin in decidual cells across gestation, but not in stromal cells from predecidualized cycling endometrium.
Coherent Modulation of a Thermal Beam

We show that the coherent modulation of a beam from an incoherent source, such as an incandescent lamp, induces correlations between the normal modes describing the beam. Further, we show that it is possible to modulate the thermal beam without altering the coherence propreties, i.e., the statistical properties of the beam. We demonstrate the general properties of modulated incoherent beams by solving exactly the equations of motion for a model of a beam from a thermal source modulated by an electro-optic light-modulation crystal. When the incoherent beam is gaussian, we show that the modulation process does not alter the coherence properties of the incoherent beam.
Mate Preference and Mating Behavior of Male Helicoverpa zea (Lepidoptera: Noctuidae) Infected with the Sexually Transmitted Insect Virus Hz-2V

The affect of Hz-2V (a.k.a. gonad-specific virus) virus infection on the reproductive physiology and behavior of infected adult Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) males was examined. Virus-infected males responded and flew to calling healthy and infected females at about the same rate. Although infected males were slower in approaching healthy females and attempting to mate compared with healthy males, infected males did make sexual contacts with females that could serve to transmit virus. Unlike matings with healthy males, which result in the cessation of calling, females that had made sexual contact with infected males continued to exhibit calling behavior and were receptive to mates. Although calling behavior of both healthy and infected females was inhibited by injecting extracts of reproductive tissues from healthy males, extracts of reproductive tissues from infected males inhibited female calling to a lesser degree and for an additional night compared with extracts from healthy males. The results presented here further demonstrate the ability of Hz-2V to alter the physiology and behavior of infected insects in ways that could serve to facilitate virus transmission.
Climate change is linked to long-term decline in a stream salamander

Abstract Amphibian declines have been documented worldwide and several have been linked to climate change, but the long-term data needed to detect declines are largely restricted to pond-breeding species. This limits our knowledge of population trends in other major groups of amphibians, including stream salamanders, which have their greatest diversity in North America. I hypothesized that increasing air temperature and precipitation in northeastern North America caused abundance of the stream salamander Gyrinophilus porphyriticus in a New Hampshire population to decline between 1999 and 2010. I found a significant decline in abundance of G. porphyriticus adults over this 12-year period, and no trend in larval abundance. Adult abundance was negatively related to annual precipitation, which is predicted to increase further in the Northeast due to climate change. Analysis of a 6-year capture–mark–recapture data set for the same population showed no temporal variation in larval and adult detectability, validating the abundance data, and no variation in larval and adult survival. However, survival during metamorphosis from the larval to adult stage declined dramatically. These results suggest that increasing precipitation is causing a decline in adult recruitment, which, if it persists, will lead to local extinction. A likely mechanism for the decline in adult recruitment is mortality of metamorphosing individuals during spring and fall floods, which have increased in volume and frequency with the increase in precipitation. More broadly, this study presents strong evidence that the amphibian decline crisis extends to North America’s stream salamanders, and shows the critical need to collect population data on these species.
Wavelength and concentration dependence of Raman scattering from CdS1−xSex

Abstract We present measurement of the resonant Raman effect in the alloy system CdS1−xSex for laser photon energies both above and below the concentration-dependent energy gap. Our data show that the Raman intensities are not simply functions of the difference between the photon energy and the gap energy. These results may be partially understood in terms of a simple theoretical model which elucidates the role of local electric fields in determining Raman intensities in alloys.
The Nrf2-inducers tanshinone I and dihydrotanshinone protect human skin cells and reconstructed human skin against solar simulated UV.

Exposure to solar ultraviolet (UV) radiation is a causative factor in skin photocarcinogenesis and photoaging, and an urgent need exists for improved strategies for skin photoprotection. The redox-sensitive transcription factor Nrf2 (nuclear factor-E2-related factor 2), a master regulator of the cellular antioxidant defense against environmental electrophilic insult, has recently emerged as an important determinant of cutaneous damage from solar UV, and the concept of pharmacological activation of Nrf2 has attracted considerable attention as a novel approach to skin photoprotection. In this study, we examined feasibility of using tanshinones, a novel class of phenanthrenequinone-based cytoprotective Nrf2 inducers derived from the medicinal plant Salvia miltiorrhiza, for protection of cultured human skin cells and reconstructed human skin against solar simulated UV. Using a dual luciferase reporter assay in human Hs27 dermal fibroblasts pronounced transcriptional activation of Nrf2 by four major tanshinones [tanshinone I (T-I), dihydrotanshinone (DHT), tanshinone IIA (T-II-A) and cryptotanshinone (CT)] was detected. In fibroblasts, the more potent tanshinones T-I and DHT caused a significant increase in Nrf2 protein half-life via blockage of ubiquitination, ultimately resulting in upregulated expression of cytoprotective Nrf2 target genes (GCLC, NQO1) with the elevation of cellular glutathione levels. Similar tanshinone-induced changes were also observed in HaCaT keratinocytes. T-I and DHT pretreatment caused significant suppression of skin cell death induced by solar simulated UV and riboflavin-sensitized UVA. Moreover, feasibility of tanshinone-based cutaneous photoprotection was tested employing a human skin reconstruct exposed to solar simulated UV (80 mJ/cm2 UVB; 1.53 J/cm2 UVA). The occurrence of markers of epidermal solar insult (cleaved procaspase 3, pycnotic nuclei, eosinophilic cytoplasm, acellular cavities) was significantly attenuated in DHT-treated reconstructs that displayed increased immunohistochemical staining for Nrf2 and γ-GCS together with the elevation of total glutathione levels. Taken together, our data suggest the feasibility of achieving tanshinone-based cutaneous Nrf2-activation and photoprotection.
Phase behavior, dynamic contacting and detergency in systems containing triolein and nonionic surfactants

Abstract Systems containing the pure triglyceride triolein, pure nonionic surfactants and water have been studied. At low temperatures both the lamellar liquid crystalline phase Lα and the isotropic liquid phase termed D′ or L3 solubilize little triolein and have interfacial tensions with triolein of a few tenths mN m−1. However, above a particular temperature in each system phase compositions change rapidly. For the C12E3 system, the oil phase, at low temperatures mainly triolein and surfactant, experiences an abrupt increase in water solubilization and becomes an oil-continuous microemulsion. In contrast, for the C12E5 system, oil phase composition changes little, but the D′ phase suddenly becomes capable of solubilizing triolein and exhibits behavior similar to that of microemulsions in hydrocarbon systems although surfactant concentration is considerably higher than in typical microemulsions. Behavior intermediate between these two situations occurs in the C12E4 system. The differences in phase behavior are reflected both in the dynamic behavior seen by videomicroscopy when a surfactant-water mixture contacts triolein and in removal of triolein from polyester/cotton fabric during washing. Behavior of the C12E5 system is similar to that reported previously for hydrocarbon systems with maximum soil removal found near the apparent phase inversion temperature (PIT) and an intermediate D′ phase seen in contacting experiments near the PIT. For the C12E3 and C12E4 systems the dynamic behavior is different and soil removal is lower than with C12E5. For mixtures of triolein and n-hexadecane typical microemulsion phases D are found at low triolein contents and the D′ phase having low solubilization of both oils at high triolein contents. For intermediate compositions the phase behavior includes a narrow four-phase region where both D and D′ phases coexist with excess oil and water. Detergency experiments for a mixture containing equal parts by weight of the two oils showed greater overall soil removal than for pure triolein and a slightly greater removal of the hydrocarbon than of the triglyceride at all temperatures. The former result probably stems from the lower interfacial tensions found for the mixed soil, the latter from preferential solubilization of hydrocarbon into surfactant-rich phases initially present or formed during the washing process.
Quantum confinement in germanium nanocrystal thin films

Thin films of semiconductor nanocrystals with tunable optical properties are promising materials for new device applications, but progress has been slow for group IV materials. We report absorption measurements near the absorption edge of thin films of germanium nanocrystals synthesized in a plasma and impacted onto substrates. Band gaps extracted from the absorption data vary from the near-bulk value of 0.73 eV for 9.0 nm nanocrystals to over 1.0 eV for 4.7 nm nanocrystals. These values are comparable to those reported for isolated, non-interacting germanium nanocrystals, indicating minimal loss of quantum confinement upon dense film formation. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Hydrogen exchange and structural dynamics of proteins and nucleic acids

Though the structures presented in crystallographic models of macromolecules appear to possess rock-like solidity, real proteins and nucleic acids are not particularly rigid. Most structural work to date has centred upon the native state of macromolecules, the most probable macromolecular form. But the native state of a molecule is merely its most abundant form, certainly not its only form. Thermodynamics requires that all other possible structural forms, however improbable, must also exist, albeit with representation corresponding to the factor exp( — Gi/RT) for each state of free energy Gi (see Moelwyn-Hughes, 1961), and one appreciates that each molecule within a population of molecules will in time explore the vast ensemble of possible structural states.
Life in the Clouds of Venus

WHILE the surface conditions of Venus make the hypothesis of life there implausible, the clouds of Venus are a different story altogether. As was pointed out some years ago1, water, carbon dioxide and sunlight—the prerequisites for photosynthesis—are plentiful in the vicinity of the clouds. Since then, good additional evidence has been provided that the clouds are composed of ice crystals at their tops2,3, and it seems likely that there are water droplets toward their bottoms4. Independent evidence for water vapour also exists5. The temperature at the cloud tops is about 210° K, and at the cloud bottoms is probably at least 260–280° K (refs. 4 and 6). Atmospheric pressure at this temperature level is about 1 atm.7. The observed planetary albedo falls steeply in the violet and ultra-violet8, which accounts for the pale lemon yellow colour of Venus. The albedo decline would not be expected for pure ice particles, and must therefore be caused by some contaminant. Dust, ozone, C3O2 and other gases may possibly explain these data but, whatever the explanation, the ultra-violet flux below the clouds is likely to be low. If small amounts of minerals are stirred up to the clouds from the surface, it is by no means difficult to imagine an indigenous biology in the clouds of Venus. What follows is one such speculation.
Introduction of "natural" killer' cells by BCG.

THE past decade has witnessed numerous attempts to suppress tumour growth by the administration of immune stimulants. Notable successes have been achieved, particularly following the intralesional injection of Bacille Calmette-Guerin (BCG) which has been observed to cause the regression of local tumour nodules in both experimental animals1,2 and man3–5. Although there is some controversy as to the mode of action of BCG, it has become widely accepted that its anti-tumour effects are principally mediated through host macrophages, “activated” by the immunostimulant6–8. Observations we have recently made in studies of the peritoneal exudates of BCG-infected mice suggest an alternative possibility: that tumour destruction is caused by a non-macrophage population of cytotoxic cells which is induced by BCG immunisation.
Intradural herniation of thoracic disc: CT metrizamide myelography

Abstract A case of intradural herniation of a thoracic (T12-L1) intervertebral disc is reported. On metrizamide myelography, this lesion resembled an intradural extramedullary tumor with an extradural component. A computed tomographic (CT) scan taken immediately after the myelogram, showed gas in the spinal anal and in the intervertebral disc. In addition, it showed a high-density mass located in the ventral epidural space and also intradurally. The density of this soft-tissue mass was identical to that of the intervertebral disc. CT provided very important information regarding the precise location and probable etiology of the lesion, and the success of surgery.
The CDF online system

Abstract The CDF Online System is described. A VAX cluster acts as the primary control and monitoring environment for a large FASTBUS-based data-acquisition system. The system is highly redundant and allows multiple experiments (or partitions) to run simultaneously on subsets of the experimental apparatus for performing calibrations or diagnostics in parallel. For physics runs, consumer processes residing on any of the VAX computers can access the data in parallel, allowing sophisticated online monitoring to be performed.
Position of the fabella relative to the path of the common peroneal nerve across the lateral head of the gastrocnemius muscle

The fabella is an inconstant sesamoid bone located in the origin of the lateral head of the gastrocnemius muscle. The presence of a fabella has been associated with a number of pathologies including compression injury of the common peroneal nerve (CPN) as it crosses the lateral head of the gastrocnemius. This study was designed to determine the incidence of fabellae and the geometric relationship of the fabella to the CPN using anatomical dissection. In the 78 specimens examined, the incidence of fabellae was 27%, a figure near the high end of the previously reported range. To our knowledge, the geometric relationship of the fabella to the CPN has not previously been reported. Using measurements taken during dissection of fabellae, the zone of potential locations of the fabella overlapped 26.0% of the length of the CPN across the lateral head of the gastroenemius. © 1993 Wiley-Liss, Inc.
Toward a Comprehensive Model of Jet Noise Using an Acoustic Analogy

An acoustic analogy is developed to predict the noise from jet flows. It contains two source models that independently predict the noise from turbulence and shock wave shear layer interactions. The acoustic analogy is based on the Euler equations and separates the sources from propagation. Propagation effects are taken into account by approximating the vector Green’s function of the linearized Euler equations with the use of a locally parallel mean flow assumption. A statistical model of the two-point cross correlation of the velocity fluctuations is used to describe the turbulence. The acoustic analogy attempts to take into account the correct scaling of the sources for a wide range of nozzle pressures and temperature ratios. It does not make assumptions regarding fine- or large-scale turbulent noise sources, self- or shear noise, or convective amplification. The acoustic analogy is partially informed by three-dimensional steady Reynolds-averaged Navier–Stokes solutions that include the nozzle geometry. ...
Increased ventilation in runners during running as compared to walking at similar metabolic rates

At similar levels of carbon dioxide production ( $$\dot VCO_2 $$ ) and oxygen consumption ( $$\dot VO_2 $$ ), runners have been shown to have a greater minute ventilation ( $$\dot V_E $$ ) during running as compared to walking. The mechanism responsible for these differences has yet to be identified. To determine if these differences are a result of differences in acid-base status, potassium (K+), norepinephrine and/or epinephrine levels, seven well-trained runners completed walk and run tests at similar $$\dot VO_2 $$ and $$\dot VCO_2 $$ levels. The occurrence of entrainment of the breathing and stride frequencies during both walking and running was also determined. $$\dot V_E $$ was significantly greater during the run as compared to the walk, 73.7 (2.2) versus 68.6 (2.0)l·min−1, respectively, despite the similarity in $$\dot VO_2 $$ and $$\dot VCO_2 $$ levels. Alveolar ventilation was not significantly different between the run and the walk, 60.4 (4.7) versus 59.6 (4.4)l·min−1, respectively. Dead space ventilation was found to be significantly greater during running as compared to walking, 13.3 (3.2) versus 9.0 (4.7)l·min−1, respectively. The increases in $$\dot V_E $$ were due to increases in breathing frequency and decreases in tidal volume during the run as compared to the walk. Arterial partial pressures of C02 (P aCO2) were not significantly different when comparing walking and running to rest values nor when comparing walking and running. Arterial pH was significantly lower during walking as compared to rest and running. Bicarbonate levels were significantly lower during walking as compared to rest. Lactate was significantly greater during walking as compared to rest and to running. K+ levels were significantly higher during walking and running as compared to rest. Epinephrine and norepinephrine levels were not significantly different between running and walking. During the walk, six of the seven subjects entrained their breathing frequency to the stride frequency, and during the run three of the seven subjects demonstrated entrainment. Results from this investigation do not support mediation of $$\dot V_E $$ under the present experimental conditions by changes in arterial levels of humoral factors previously shown to influence $$\dot V_E $$ .
Skill Assessment of Resolving Ocean Surface Current Structure Using Compact-Antenna-Style HF Radar and the MUSIC Direction-Finding Algorithm

A skill analysis of the Multiple Signal Characterization (MUSIC) algorithm used in compact-antennastyle HF radar ocean current radial velocity/bearing determination is performed using simulation. The simulation is based upon three collocated antennas (two cross loops and a monopole with ideal gain patterns) in a geometry similar to the 25-MHz SeaSonde HF radar commercially available from Coastal Ocean Dynamics Applications Radar (CODAR) Ocean Sensors, Palo Alto, California. The simulations consider wind wave/current scenarios of varying complexity to provide insight to the accuracy of surface current retrievals and the inherent limitations of the technique, with a focus on the capabilities of the MUSIC algorithm itself. The influence of second-order scatter, interference, and stationary target scatter are not considered. Simple error reduction techniques are explored and their impacts quantified to aid in operational system configuration and encourage areas of further research. Increases in skill between 55% and 100% using spatial averaging, and between 14% and 33% using temporal averaging, are realized, highlighting the utility of these techniques. When these error-flagging and averaging techniques are employed, individual range cell skill metrics are found to be as high as 0.94 for simple currents at a high signal-to-noise ratio (SNR), while more complex currents achieve a maximum skill metric of 0.72 for the same SNR. These simulations, conducted under ideal conditions, provide insight to understanding the variables, which influence the accuracy of surface currents retrieved using MUSIC.
Frequency domain measures of heart period variability and mortality after myocardial infarction.

BACKGROUNDWe studied 715 patients 2 weeks after myocardial infarction to establish the associations between six frequency domain measures of heart period variability (HPV) and mortality during 4 ye...
Variational formulation of the coupled-state impact-parameter method

In the coupled-state impact-parameter method, the exact impact-parameter wave function is approximated by a trial impact-parameter wave function which is a finite linear combination of $N$ basis vectors with time-dependent coefficients. In the standard approach the coefficients are determined by solving the equations obtained by projecting the impact-parameter Schr\"odinger equation with the exact wave function replaced by the trial wave function onto the $N$ basis vectors which define the trial wave function. It is well known that this method gives variational estimates of the transition amplitudes if the basis vectors represent physical states. However, if in proton-hydrogen-atom scattering Sturmian basis vectors, which are for the most part nonphysical basis vectors, are used, the method is not variational. In this paper it is shown that if Sturmian basis vectors are used the method can be made variational by projecting the Schr\"odinger equation with the exact wave function replaced by the trial wave function onto the physical basis vectors of interest rather than onto the Sturmian basis vectors; the resultant equations are no more difficult to solve than the standard equations. It is also shown that useful variational bounds on the error of the estimate of a transition amplitude exist only if the trial wave function is expanded in terms of a physical basis set.
NMR spectroscopic analyses of liver phosphatidylcholine and phosphatidylethanolamine biosynthesis in rats exposed to peroxisome proliferators-A class of nongenotoxic hepatocarcinogens.

Peroxisome proliferators (PPs) are commercial/industrial chemicals that display tumor promoter activity in rodents. The mechanism is not completely understood, and our ability to predict tumorigenicity a priori is even less developed. Wy-14,643, perfluorooctanoic acid (PFOA), and di(2-ethylhexyl)phthalate (DEHP) are strong, moderate, and weak tumor promoters, respectively, while perfluorodecanoic acid (PFDA) lacks promoter activity. This investigation examined the effects of these PPs on the biosyntheses of phosphatidylcholine (PtdC) and phosphatidylethanolamine (PtdE) in rat liver. After exposure to PPs, rats were administered [1-(13)C]choline + [2-(13)C]ethanolamine and liver extracts were analyzed by (31)P and (13)C NMR. The ratio of choline-derived to ethanolamine-derived phospholipids, R(c/e), was significantly affected by all PPs (p PFOA > DEHP > control > PFDA. The amounts of PtdC derived via the CDP-choline pathway versus PtdE-N-methyltransferase (PEMT) activity was 71 vs 29% in controls. This distribution was significantly affected by treatments with Wy-14,643 (95 vs 5%), DEHP (87 vs 13%), and PFDA (39 vs 61%) (p < 0.02). Data suggest that Wy-14,643, PFOA, and DEHP cause a preference for choline and the CDP-choline pathway for biosynthesis of PtdC. Additionally, Wy-14,643 and DEHP inhibited the PEMT pathway. In contrast, PFDA-treated rats showed a preference for ethanolamine, and PtdC was predominately synthesized through the PEMT pathway. These data corroborate studies by Vance and co-workers which suggest that the pathways for PtdC biosynthesis are important for hepatocarcinogenesis. Further studies to evaluate the potential of these measurements as a biomarker for PP-associated tumorigenesis is warranted.