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The nucleation and growth of calcium–silicate–hydrate (C–S–H) is of fundamental importance for the strength development and durability of the concrete. However, the nucleation process of C–S–H is still not fully understood. The present work investigates how C–S–H nucleates by analyzing the aqueous phase of hydrating tricalcium silicate (C3S) by applying inductively coupled plasma-optical emission spectroscopy as well as analytical ultracentrifugation. The results show that the C–S–H formation follows non-classical nucleation pathways associated with the formation of prenucleation clusters (PNCs) of two types. Those PNCs are detected with high accuracy and reproducibility and are two species of the 10 in total, from which the ions (with associated water molecules) are the majority of the species. The evaluation of the density and molar mass of the species shows that the PNCs are much larger than ions, but the nucleation of C–S–H starts with the formation of liquid precursor C–S–H (droplets) with low density and high water content. The growth of these C–S–H droplets is associated with a release of water molecules and a reduction in size. The study gives experimental data on the size, density, molecular mass, and shape and outlines possible aggregation processes of the detected species. [ABSTRACT FROM AUTHOR]

Background: The DV-QoL is a 17-item questionnaire measuring health-related quality of life in patients affected by symptomatic diverticular disease, covering four domains: physical symptoms, concerns, feelings, and behavioral changes. Given the lack of a diverticulitis-specific questionnaire to be used for German-speaking patients, we prospectively validated the German version of the DV-QoL. Methods: German-speaking patients with CT-confirmed history of recurrent diverticular disease admitted to a Swiss surgical department completed the German version of the DV-QoL, along with short form-36 (SF-36) and the Gastrointestinal Quality of Life Index (GIQLI). Reliability was examined using exploratory and confirmatory factor analysis, a Martin-Loef test, and Cronbach's alpha. For convergent validity testing, correlations were calculated with the GIQLI and SF-36. Discriminant validity tests included age and gender. Results: We included 121 patients, of whom 77 were admissions for elective surgery and 44 presented with acute diverticulitis treated conservatively. The DV-QoL's total score showed good correlations with the GIQLI (r = − 0.77) and its subscales (r = − 0.76 to − 0.45), as well as with the SF-36's subscales (r = − 0.30 to − 0.57). No relationships were found with age or gender (p < 0.05). The Cronbach's alpha coefficient was 0.89 over all items and 0.69, 0.90, 0.78, and 0.77 for the four separated domains (physical symptoms, cognitions/concerns, feelings, and behavioral changes, respectively). A nonsignificant Martin-Loef test indicated unidimensionality (p = 1), further supported by the exploratory factor analysis, which showed an item information sharing of 65%. Conclusion: The German DV-QoL questionnaire can be used as a valid and reliable disease-specific measure for quality of life in patients with recurrent diverticular disease. [ABSTRACT FROM AUTHOR]

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Radiation damage and stimulated desorption of nucleotides 2′-deoxyadenosine 5′-monophosphate (dAMP), adenosine 5′-monophosphate (rAMP), 2′-deoxycytidine 5′-monophosphate (dCMP), and cytidine 5′-monophosphate (rCMP) deposited on Au have been measured using x-rays as both the probe and source of low energy secondary electrons. The fluence dependent behavior of the O-1s, C-1s, and N-1s photoelectron transitions was analyzed to obtain phosphate, sugar, and nucleobase damage cross sections. Although x-ray induced reactions in nucleotides involve both direct ionization and excitation, the observed bonding changes were likely dominated by the inelastic energy-loss channels associated with secondary electron capture and transient negative ion decay. Growth of the integrated peak area for the O-1s component at 531.3 eV, corresponding to cleavage of the C—O—P phosphodiester bond, yielded effective damage cross sections of about 23 Mb and 32 Mb (1 Mb = 10−18 cm2) for AMP and CMP molecules, respectively. The cross sections for sugar damage, as determined from the decay of the C-1s component at 286.4 eV and the glycosidic carbon at 289.0 eV, were slightly lower (about 20 Mb) and statistically similar for the r- and d- forms of the nucleotides. The C-1s component at 287.6 eV, corresponding to carbons in the nucleobase ring, showed a small initial increase and then decayed slowly, yielding a low damage cross section (∼5 Mb). Although there is no statistical difference between the sugar forms, changing the nucleobase from adenine to cytidine has a slight effect on the damage cross section, possibly due to differing electron capture and transfer probabilities. [ABSTRACT FROM AUTHOR]

This study evaluates the impact of an intervention targeting high-risk behaviors among diverse, alcohol-using adults living with HIV (N = 267) from 2009 to 2013 in Miami, FL. The intervention took place in a group setting for eight sessions over 4 weeks and was compared to a didactic health promotion group. Assessments were conducted pre-intervention, post-intervention, and at 3, 6, and 12 months follow-up. Intervention participants (48% of sample) evidenced greater knowledge about HIV, more condom self-efficacy, and greater intentions to use condoms after participation. This was particularly noteworthy because associations among knowledge about HIV, more condom self-efficacy, and greater intentions to use condoms were negatively associated with intervention status at baseline. Participants also reported fewer heavy drinking days after participating in the intervention than those in the control group. Greater HIV knowledge, more condom self-efficacy and intentions to use condoms predicted more condom assertiveness; greater intentions to use condoms predicted fewer unprotected sexual behaviors. These findings underscore the importance of taking a comprehensive, multi-systemic approach to address risky behaviors in high-risk, diverse populations. [ABSTRACT FROM AUTHOR]

The microstructural evolution within plated Cu films has been investigated using high-resolution x-ray diffraction, revealing a change in strain state within the recrystallized grains and the surrounding matrix with time. By approximating the case of an isolated grain in a randomly textured material as an Eshelby inclusion in an elastically isotropic matrix, we can determine the elastic strain energy in addition to the interaction strains that develop within the grain due to the effects of elastic anisotropy. The elastic strain energy density generated by a grain possessing cubic symmetry with arbitrary orientation within an elastically isotropic matrix has been compared to that within a fiber-textured film, revealing that the former case possesses less strain energy. These results suggest that the recrystallization of Cu (111) grains from an electroplated film with a small, initial grain size is less energetically favorable for films exhibiting strong (111) texture than for a randomly textured film. Experimental results indicate a sequence that emerges during the recrystallization process: (111) grains grow first, suggesting that the decrease in surface energy provided by the (111) surfaces is larger than the increase in elastic strain energy created by (111) grains. For sufficiently thick films, (100) grains emerge, lowering the strain energy density in the film, after (111) grain growth has saturated because no further decrease in energy is supplied by (111) surface growth. By examining plated Cu films of different thicknesses, we correlate the appearance of recrystallized (100) grains with a threshold energy density based on the additional energy associated with (100) surfaces relative to (111) surfaces. [ABSTRACT FROM AUTHOR]

Two one-dimensional (1D) single-crystalline gallium nitride (GaN) nanostructures with periodic zigzag (type I) and diameter-modulated (type II) shapes have been synthesized by passing through ammonia over a mixture of gallium and gallium oxide (Ga2O3) powders held at elevated temperature. The process was catalyzed by the dispersion of thio-capped Au nanoparticles on the substrate onto which GaN nanostructures were condensed. The transformation between these two nanostructure morphologies was also observed. A possible growth model for the zigzag-shaped nanostructures is proposed, in which the formation of the zigzag nanostructures results from the construction of two different nanoscale unit cells. This work provides an avenue to a group of 1D nanostructures with a zigzag shape. The possibility to form 1D nanostructures yet to be discovered by changing the stacking direction of the (0001) plane will facilitate the fabrication of nanoscale functional devices as well as our understanding of the growth behavior of nanoscale crystallites. [ABSTRACT FROM AUTHOR]

Synchrotron-radiation glancing-incidence and angle-resolved photoelectron spectroscopy (PES) is used to study the oxides grown in air on a single-crystal Nb(100) surface. Both core-level and valance-band PES are measured for various heat treatments. Glancing-incidence excitation was used to characterize the outer 2-nm Nb2O5 layer without influence from the substrate and to profile through various oxides by varying the incidence angle. Immediately adjacent to this amorphous layer is a layer of NbO2, which contributes to the density of states at 1.2 eV below the Fermi level. Thereafter, there exist other oxides that interface with the metal substrate. Annealing at 430 K induces a “mild” chemical reaction, which is contained essentially in the oxide layer. Annealing at 550 K causes oxygen diffusion into the metal and leaves an oxide layer consisting primarily of Nb2O and a roughened surface, as evidenced by angle-resolved photoemission measurements. Oxide composition alteration caused by annealing at these moderated temperatures is believed to be interface mediated. [ABSTRACT FROM AUTHOR]

Resistance saturation as a function of current density, stripe length, stripe width, and temperature is investigated for a two-level structure with Ti/AlCu/Ti/TiN stripes and interlevel W stud vias. A simple model based on first principles is presented, which relates the maximum fractional resistance change to the current density and stripe length. Experimental results for stripe lengths of 30, 50, 70, and 100 μm are in good agreement with the model predictions. Estimated void sizes based on the resistance saturation data are consistent with the actual void sizes determined from scanning electron microscopy analysis. A weak temperature dependence is found for 0.33 μm-wide samples in the range 170–250°C, while a strong width dependence is observed between 0.33 and 1.50 μm- wide samples. The width dependence is qualitatively explained in terms of a relaxed bulk modulus that depends on the aspect ratio of the interconnect lines. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A total of 264 implants was placed in 143 patients using different immediate or delayed-immediate implant placement techniques in 12 different centers participating in a prospective multicenter study. The reason for tooth extraction was evaluated; bone quality and quantity were classified; socket depths were registered; and data on implant type, size, and position were collected. One hundred thirty-nine suprastructures were placed on 228 implants in 126 patients. A follow-up evaluation was done on 125 patients after 1 year of loading and on 107 patients after 3 years of loading. Clinical parameters (bleeding or not bleeding, pocket depth, and implant mobility) were evaluated after 1 and 3 years, and the marginal bone level after 1 year of loading was measured on radiographs. Clinical comparisons were performed to evaluate implant loss in relation to implant type, size, position, bone quality and quantity, socket depth, reason for tooth extraction, and placement method. In addition, life table analysis was done for cumulative implant survival rates. There was no clinical difference with respect to socket depth or when comparing the different placement methods. A higher failure rate was found for short implants in the posterior region of the maxilla and when periodontitis was cited as a reason for tooth extraction. Mean marginal bone resorption from the time of loading to the 1-year follow-up was 0.8 mm in the maxilla and 0.5 mm in the mandible. Over a period of 3 years, the implant survival rate was 92.4% in the maxilla and 94.7% in the mandible. [ABSTRACT FROM AUTHOR]

Objective: Several studies have found an increase in hippocampal volume following electroconvulsive therapy (ECT), but the effect on cortical thickness has been less investigated. We aimed to examine the effects of ECT on cortical thickness and their associations with clinical outcome. Method: Using 3 Tesla MRI scanner, we obtained T1‐weighted brain images of 18 severely depressed patients at three time points: before, right after and 6 months after a series of ECT. The thickness of 68 cortical regions was extracted using Free Surfer, and Linear Mixed Model was used to analyze the longitudinal changes. Results: We found significant increases in cortical thickness of 26 regions right after a series of ECT, mainly within the frontal, temporal and insular cortex. The thickness returned to the baseline values at 6‐month follow‐up. We detected no significant decreases in cortical thickness. The increase in the thickness of the right lateral orbitofrontal cortex was associated with a greater antidepressant effect, r = 0.75, P = 0.0005. None of the cortical regions showed any associations with cognitive side effects. Conclusion: The increases in cortical thickness induced by ECT are transient. Further multimodal MRI studies should examine the neural correlates of these increases and their relationship with the antidepressant effect. [ABSTRACT FROM AUTHOR]

We present an analysis of the extensive photolysis of an adsorbate resulting from adsorbate core-level excitation. The system studied was SiF4 adsorbed on Ge(100) at 30 K. Photolysis fragments and molecular species (identified with Si 2p soft x-ray photoemission spectroscopy) were measured as a function of monochromatic (140-eV) photon exposure and adsorbate coverage. The photolysis cross sections for 55–140-eV photons were determined and the neutral photon-stimulated desorption cross section for a selected SiF4 excitation is also presented. In the Si 2p absorption region, it was found that the photolysis cross section was one to three times the preedge value and comparable in magnitude to that of gas phase photoabsorption, while the total yield increased at most by a factor of 1.4. Both of these observations indicate that direct core excitation of the adsorbate is a major path by which photolysis occurs as opposed to an indirect, substrate-driven one. © 1995 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We present evidence that demonstrates photolysis of SiF4 adsorbed on Ge(100) at 30 K. Silicon 2p soft x-ray photoemission spectroscopy (PES) indicates that upon irradiation, the molecularly adsorbed SiF4 dissociates into SiFn species (where n=0,1,2,3) and desorbs as molecular SiF4. Also, the Si 2p PES from undissociated molecules exhibits a number of distinct kinetic-energy shifts. These are attributed to anisotropic adsorption in which different molecular sites have different apparent Si 2p binding energies. A structure of the adsorbate layer is proposed to account for the varying core hole screening. Examination of the gas phase during irradiation confirms molecular desorption and shows the system to have a significant neutral molecular desorption yield. Changes in the valence-level photoemission structure and signal intensity are consistent with the observed fragmentation and desorption, both of which lead to disappearance of the molecularly adsorbed species. © 1995 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We have measured vibrational branching ratios for 2σ-1u photoionization of N2 in an effort to elucidate fundamental aspects of continuum channel coupling. Calculations have shown that photoejection of a 2σu electron from N2 should be influenced by a shape resonance in the 3σg →εσu photoionization channel and that this continuum channel coupling can result in deviations from Franck–Condon behavior for the resulting N+2(B 2Σ+u) ion. In the present study, the N2 molecules are ionized by monochromatic synchrotron radiation (25

We have measured vibrationally resolved fluorescence from SiF+4(D 2A1) photoions to determine the vibrational branching ratio σ[v=(1,0,0,0)]/σ[v=(0,0,0,0)] in the excitation energy range 22

We have performed the first experiments to examine the neutral fragmentation paths following direct core-level excitation in a molecule. Using monochromatized synchrotron radiation in the range 100–140 eV, we have monitored the dispersed UV/optical fluorescence resulting from excitation of a Si 2p electron in SiF4. The main features in the fluorescence spectrum have been identified as emission from the SiF+4 D state and from excited SiF, Si, F, and Si+. Features in the fluorescence excitation spectra are assigned to excitation of a Si 2p electron to unoccupied valence orbitals, Rydberg orbitals, and shape resonances. There is a large enhancement in the yield of excited-state fragments following core-to-Rydberg excitation, which is due to the greater probability of the core-excited Rydberg state decaying, via a resonant Auger process, to highly excited, unbound states of SiF+4. [ABSTRACT FROM AUTHOR]

Focuses on a study on synchroton radiation of diamond nucleation and growth on silicon. Information on the x-ray photoelectron spectroscopy; Experimental setup; Results and discussion.

Presents a study which examined the effects of low energy hydrogen[sub2] plasma exposure on the surface defect chemistry and the electronic structure of cadmium telluride. Information on the effects of the incorporation of atomic hydrogen into semiconductors; Experimental details; Results.

Presents information on a study which investigated the soft x-ray induced photoluminescence of porous silicon in the optical region. Information on x-ray absorption fine structure; Experimental details; Results and discussion; Conclusions.

Presents a study that developed a method used on the bending beam technique to measure the thermal stresses of fine lines confined by a dielectric layer. Employment of the method to determine the thermal stresses of aluminum lines passivated by a silicon dioxide overlayer; Effect of quartz confinement; Deduction of the triaxial stress components of metal.

Focuses on the use of broadband synchrotron radiation to induce selective area surface doping of boron into silicon. Instrument used to perform electron energy analysis; Information on the spectral variations observed in the irradiated region.

Provides information on a study concerning the deposition of boron and boron carbide films through synchrotron radiation. Process of decaborane decomposition; Behavior of boron films in cases of dissociative adsorption; Discussion of synchrotron-radiation growth rate in boron films.

Presents a study which examined the kinetics and mechanism of oxidation of silicon germanide alloys deposited epitaxially onto silicon substrates by low-temperature chemical vapor deposition. Role of germanium in oxidation; Electrical properties of the oxides formed under the conditions; Comparison with the mechanism of oxidation of pure silicon.

We use X-ray Excited Luminescence Microscopy to investigate the elemental and layer resolved magnetic reversal in an interlayer exchange coupled (IEC) epitaxial Fe/Cr wedge/Co heterostructure. The transition from strongly coupled parallel Co-Fe reversal for Cr thickness tCr<0.34 nm to weakly coupled layer independent reversal for tCr>1.5 nm is punctuated at 0.34Cr<1.5 nm by a combination of IEC guided domain wall motion and stationary zig zag domain walls. Domain walls nucleated at switching field minima are guided by IEC spatial gradients and collapse at switching field maxima. [ABSTRACT FROM AUTHOR]

We use X-ray Excited Luminescence Microscopy to investigate the elemental and layer resolved magnetic reversal in an interlayer exchange coupled (IEC) epitaxial Fe/Cr wedge/Co heterostructure. The transition from strongly coupled parallel Co-Fe reversal for Cr thickness tCr < 0.34 nm to weakly coupled layer independent reversal for tCr > 1.5 nm is punctuated at 0.34 < tCr < 1.5 nm by a combination of IEC guided domain wall motion and stationary zig zag domain walls. Domain walls nucleated at switching field minima are guided by IEC spatial gradients and collapse at switching field maxima. [ABSTRACT FROM AUTHOR]

We develop and use a circulation model to estimate hydrographical and ecological changes in the isolated basin water of the Bornholm Basin. By pumping well-oxygenated so-called winter water to the greatest depth, where it is forced to mix with the resident water, the rate of deepwater density reduction increases as well as the frequency of intrusions of new oxygen-rich deepwater. We show that pumping 1000 m³ s-1 should increase the rates of water exchange and oxygen supply by 2.5 and 3 times, respectively. The CRV (cod reproduction volume), the volume of water in the isolated basin meeting the requirements for successful cod reproduction (S > 11, O2 > 2 mL L-1), should every year be greater than 54 km3, which is an immense improvement, since it has been much less in certain years. Anoxic bottoms should no longer occur in the basin, and hypoxic events will become rare. This should permit extensive colonization of fauna on the earlier periodically anoxic bottoms. Increased biomass of benthic fauna should also mean increased food supply to economically valuable demersal fish like cod and flatfish. In addition, re-oxygenation of the sediments should lead to increased phosphorus retention by the sediments. [ABSTRACT FROM AUTHOR]

The Orbiting Carbon Observatory-2 (OCO-2), launched on 2 July 2014, is a NASA mission designed to measure the column-averaged CO2 dry air mole fraction, XCO2. Towards that goal, it will collect spectra of reflected sunlight in narrow spectral ranges centered at 0.76, 1.6 and 2.0 μm with a resolving power (λ/Δλ) of 20 000. These spectra will be used in an optimal estimation framework to retrieve XCO2. About 100000 cloud free soundings of XCO2 each day will allow estimates of net CO2 fluxes on regional to continental scales to be determined. Here, we evaluate the OCO-2 spectrometer performance using pre-launch data acquired during instrument thermal vacuum tests in April 2012. A heliostat and a diffuser plate were used to feed direct sunlight into the OCO-2 instrument and spectra were recorded. These spectra were compared to those collected concurrently from a nearby high-resolution Fourier Transform Spectrometer that was part of the Total Carbon Column Observing Network (TCCON). Using the launch-ready OCO-2 calibration and spectroscopic parameters, we performed total column scaling fits to all spectral bands and compared these to TCCON results. On 20 April, we detected a CO2 plume from the Los Angeles basin at the JPL site with strongly enhanced short-term variability on the order of 1 % (3-4 ppm). We also found good (< 0.5 ppm) inter-footprint consistency in retrieved XCO2. The variations in spectral fitting residuals are consistent with signal-to-noise estimates from instrument calibration, while average residuals are systematic and mostly attributable to remaining errors in our knowledge of the CO2 and O2 spectroscopic parameters. A few remaining inconsistencies observed during the tests may be attributable to the specific instrument setup on the ground and will be re-evaluated with in-orbit data. [ABSTRACT FROM AUTHOR]

The Orbiting Carbon Observatory-2 (OCO-2), launched on 2 July 2014, is a NASA mission designed to measure the column-averaged CO2 dry air mole fraction, XCO2. Towards that goal, it will collect spectra of reflected sun-light in narrow spectral ranges centered at 0.76, 1.6 and 2.0 µm with a resolving power (λ/△λ) of 20 000. These spectra will be used in an optimal estimation framework to retrieve XCO2. About 100 000 cloud free soundings of XCO2 each day will allow estimates of net CO2 fluxes on regional to continental scales to be determined. Here, we evaluate the OCO-2 spectrometer performance using pre-launch data acquired during instrument thermal vacuum tests in April 2012. A heliostat and a diffuser plate were used to feed direct sunlight into the OCO-2 instrument and spectra were recorded. These spectra were compared to those collected concurrently from a nearby high-resolution Fourier Transform Spectrometer that was part of the Total Carbon Column Observing Network (TCCON). Using the launch-ready OCO-2 calibration and spectroscopic parameters, we performed to tal column scaling fits to all spectral bands and compared these to TCCON results. On 20 April, we detected a CO2 plume from the Los Angeles basin at the JPL site with strongly enhanced short-term variability on the order of 1% (3-4 ppm). We also found good (<0.5 pppm) inter-footprint consistency in retrieved XCO2. The variations in spectral fitting residuals are consistent with signal-to-noise estimates from instrument calibration, while average residuals are systematic and mostly attributable to remaining errors in our knowledge of the CO2 and O2 spectroscopic parameters. A few remaining inconsistencies observed during TVAC may be attributable to the specific instrument setup on the ground and will be re-evaluated with in-orbit data, when the instrument is expected to be in a much more stable environment. [ABSTRACT FROM AUTHOR]

Our regional cord blood screening programme for detecting neonatal hypothyroidism using initial cord blood thyroxine (T4) determinations, with supplemental thyrotropin (TSH), and triiodothyronine resin uptake (T3U) measurements, gave an incidence of thyroid abnormalities of 1/3000 births, with 1/5000 infants having severe primary hypothyroidism. No hypothyroid infant detected in the programme had been suspected clinically before the screening and, in retrospect, only a few babies had any signs of hypothyroidism. Supplemental TSH and T3U determinations were required on 8-12% of the population screened initially with a T4 test to avoid missing affected cases. With an initial T4 and supplementary TSH and T3U testing on cord blood serum, recalls to exclude primary hypothyroidism were reduced to 0.16% of the screened population. The incidence of abnormalities detected in this cord blood screening programme was comparable with that reported by others using neonatal dried blood screening methods, indicating that cord blood screening can be effective provided the appropriate recall criteria and transport conditions are used. Nevertheless, for several practical reasons, neonatal dried blood methods are recommended as the screening test of choice for surveying large populations over extensive geographical areas. [ABSTRACT FROM AUTHOR]

We have characterized a voltage-sensitive chloride channel from cardiac sarcoplasmic reticulum (SR) following reconstitution of porcine heart SR into planar lipid bilayers. In 250 mM KCl, the channel had a main conductance level of 130 pS and exhibited two substrates of 61 and 154 pS. The channel was very selective for Cl- over K+ or Na+ (PK+/PCl- = 0.012 and PNa+/PCl- approximately 0.040). It was permeable to several anions and displayed the following sequence of anion permeability: SCN- > I- > NO3- approximately Br- > Cl- > F- > HCOO-. Single-channel conductance saturated with increasing Cl- concentrations (Km = 900 mM and gamma max = 488 pS). Channel activity was voltage dependent, with an open probability ranging from approximately 1.0 around 0 mV to approximately 0.5 at +80 mV. From -20 to +80 mV, channel gating was time-independent. However, at voltages below -40 mV the channel entered a long-lasting closed state. Mean open times varied with voltage, from approximately 340 msec at -20 mV to approximately 6 msec at +80 mV, whereas closed times were unaffected. The channel was not Ca(2+)-dependent. Channel activity was blocked by disulfonic stilbenes, arylaminobenzoates, zinc, and cadmium. Single-channel conductance was sensitive to trans pH, ranging from approximately 190 pS at pH 5.5 to approximately 60 pS at pH 9.0. These characteristics are different from those previously described for Cl- channels from skeletal or cardiac muscle SR. [ABSTRACT FROM AUTHOR]