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An oral water load of 20 ml (kg body wt)-1 was given to seventeen patients with the nephrotic syndrome and fifteen healthy control subjects. Diuresis (D), free water clearance (CH2O), plasma concentrations of arginine vasopressin (AVP), angiotensin II (AII) and aldosterone (Aldo) were determined before and 3 times during the first 4 h after loading. In the nephrotic syndrome D was significantly lower 1-2 h after loading than in the control subjects, predominantly due to a lower CH2O (2.61 and 7.01 ml min-1 (medians), P less than 0.01). Creatinine clearance and the maximum increase in CH2O were significantly correlated in patients with the nephrotic syndrome (rho = 0.721, n = 17, P less than 0.01) and the control subjects (rho = 0.596, n = 15, P less than 0.01). AVP was reduced in both groups during loading, but AVP was clearly elevated in the patients with the nephrotic syndrome when compared to the control subjects both before (3.0 and 1.9 pmol 1(-1), P less than 0.01) and during loading. There was a significantly negative correlation between CH2O and AVP in both groups. AII and Aldo were reduced during loading, but the levels were the same in the patients and in the control group, and AII and Aldo were not correlated to CH2O. It is concluded that patients with the nephrotic syndrome excrete an oral water load more slowly than healthy control subjects, and that this phenomenon partly is due to reduced glomerular filtration rate and partly to increased AVP.

Charge photocurrent generation is a key process in solar energy conversion systems. Effective dissociation of the photo-generated electron-hole pairs (excitons) has a strong influence on the efficiency of the organic solar cells. Charge dissociation takes place at the donor/acceptor interface via charge transfer (CT) excitons, which is Coulombically bound interfacial electron- hole pairs residing at the donor/acceptor heterojunctions. The CT state represents an intermediate state between the exciton dissociation and recombination back to the ground state. Since the recombination of photo-generated charges is a major limitation for the efficiency of the organic solar cells, a thorough understanding of this loss mechanism is crucial to improve the performance of the devices. Furthermore, examining this interfacial state is of great importance in order to maximize open-circuit voltage and photocurrent simultaneously as they both depend on it[1]. As a useful method, Electroluminescence (EL) measurements can be applied to examine CT-state emission. In this method[2], CT states are created by injection of electrons and holes into the device, and the luminescence originated from free carrier recombination at the donor/acceptor interface is detected. As a less studied system, we examine here the interfacial charge transfer state recombination in DBP:C70 thin-films. The weak EL from the small molecule solar cell biased in the forward direction gives valuable information about the CT state recombination, from which the maximum open-circuit voltage can be estimated, and further can be used in the modeling and optimization of the OPV devices.[1] C. Deibe, T. Strobe, and V. Dyakonov, “Role of the charge transfer state in organic donor-acceptor solar cells,” Adv. Mater., vol. 22, pp. 4097–4111, 2010.[2] K. Tvingstedt, K. Vandewal, A. Gadisa, F. Zhang, J. Manca, and O. Inganäs, “Electroluminescence from charge transfer states in polymer solar cells,” J. Am. Chem. Soc., vol. 131, no. 3, pp. 11819–11824, 2009.

Integration of nanostructures in organic solar cells (OSCs) has been investigated intensively in the past few years as an alternative way for enhancing the power conversion efficiency of the devices. Incorporating structured electrodes in the solar cell architecture holds potential for light absorption improvement in the active layer of the devices. A prospective, cheap and large-scale compatible method for structuring the electrodes in OSCs arises by the use of anodic aluminum oxide (AAO) membranes.In the present work, aluminum films of high purity and low roughness are formed via e-beam evaporation of a few nanometers of aluminum followed by a micrometer layer of aluminum formed via sputter deposition. The samples are then anodized to form nano-scale pores of controlled sizes. The anodization of the prepared samples occurs in an electrochemical cell in H2SO4, H2C2O4 and H3PO4 solutions. Electrolyte solution variation and anodization parameters (sample temperature, voltage) control, allows for AAO pore diameter and interpore distance tuning. The fabricated AAO is selectively etched in H2CrO4/H3PO4 mixtures, in order to reveal the underlying aluminum nanoscale dimples, which are present at the bottom of the pores.For the characterization of their light-trapping properties, the dimples are covered with a thin layer of PMMA, and the impact from different dimple dimensions is investigated experimentally via laser ablation based measurements of the field enhancement, which is compared to FDTD calculations to further explain the mechanisms of light-trapping in these structures. These dimples can potentially serve as nanostructured electrodes in P3HT/PCBM bulk heterojunction organic solar cells.

Background We evaluated the effectiveness and safety of a zotarolimus-eluting (ZES) versus a sirolimus-eluting (SES) coronary stent in a large cohort of patients treated with one of these stents in Western Denmark. Methods A total of 6,122 patients treated with ZES (n=2,282) or SES (n=3,840) were followed for up to 27 months. We ascertained clinical outcomes based on national medical databases. Results Incidence of target lesion revascularization (no. per 100 person-years) was 5.3 in the ZES group compared to 1.9 in the SES group (adjusted hazard ratio (HR)=2.19, 95% confidence intervals (CI): 1.39-3.47; p=0.001). All-cause mortality was also higher in the ZES group (ZES: 6.3; SES: 3.3; adjusted HR=1.34, 95% CI: 1.05-1.72; p=0.02), while stent thrombosis (ZES: 1.2; SES: 0.5; adjusted HR=1.98, 95% CI: 0.75-5.23; p=0.14) did not differ significantly. Conclusions In agreement with previously published randomised data, this observational study indicated that the ZES was associated with an increased risk of death and TLR in a large cohort of consecutive patients.

The photovoltaic (PV) market is currently dominated by silicon solar cells, mainly due to their high power conversion efficiency. They are, however, cost inefficient, which has led to the development of solar cells based on organic semiconductors. The ease of processing organic materials, the low material and fabrication costs along with the possibility of making ultra-thin and flexible devices makes organic solar cells ideal candidates as efficient components on a future renewable energy market. Over the past ten years, investigations on the synthesis of new organic semiconductors, on morphological optimizations and on new device structures have led to improved organic solar cell performances. Nevertheless, organic solar cells still show relatively low power conversion efficiencies, mainly due to inherent drawbacks such as short exciton diffusion lengths and low carrier mobility in the organic active layer. The resulting loss mechanisms lead to hampered device performances, especially for optically thick devices. One of the approaches to improve the device performance is increasing the light absorption in the active layer, for example by using nano- or micro-structures that diffract light at specific wavelengths into large angles in the active layers1, or by using the localized surface plasmon resonance (LSPR) effect of metal nanoparticles (MNPs)2. The use of such lighttrapping mechanisms also makes it possible to improve charge extraction, as it allows for the fabrication of thinner devices without compromising light absorption. In this work, we theoretically and experimentally investigate periodically arranged colloidal gold nanoparticles in organic solar cells, and demonstrate the use of such nanostructures to improve the light absorption in and thus the efficiency of organic solar cells. We theoretically study the optical interference and absorption in multilayer stacks via numerical analysis based on finite-difference time-domain (FDTD) and transfer matrix method (TMM). Based on our model, we perform parametric studies of the influence of the size of the plasmonic nanostructures as well as the period of the periodical arrangements in organic bulk hetero-junction solar cells. In addition, we investigate experimentally the light absorption enhancement in the organic active layer by incorporating surface-ordered gold nanoparticle arrangements at the bottom of the organic active layer. The latter are fabricated with a lithography-free stamp technique, creating a centimeter scaled area with defined inter-particle spacing. Our study presents the light harvesting ability of template-assisted nanoparticle assemblies in organic solar cells and as the approach is easily scalable, it also demonstrates an efficient method for developing large-scale, low cost devices. Moreover, as the presented method is easily transferable to other platforms, it can be applied to various future device applications.

We report an optimized inverted bulk-heterojunction (P3HT:PCBM) organic solar cell geometry in order to both efficiently trap incident light within in the cell (increasing light absorption) and at the same time provide efficient transport of the generated carriers to the electrodes (reducing the active layer thicknesses). To address these issues, we have used two approaches. The first one consists of including diffraction gratings that increase the light path length in the cell and thus enhance absorption in wavelength intervals matching the absorption peak of the organic active layer on the bottomelectrode, while the second approach includes Ag nanoparticles embedded on the solar cell topelectrode, which scatter the incident light into the solar cell active layer. The solar cells containing either gratings or nanoparticles exhibit a significant enhancement on the power conversion efficiency. Furthermore, the solar cells do not contain the rare metal indium, but employ a PEDOT:PSS based transparent electrode.

Organic solar cells (OSC’s) have attracted much attention in the past years due to their low costs, light weight and mechanical flexibility. A promising method for improving the power conversion efficiencies of the devices is by incorporating structured electrodes in the solar cell architecture. That way light absorption in the active layers of the devices can be improved. A cheap and large-scale production compatible method for structuring the electrodes in OSC’s is by the use of Anodic Alumina Oxide (AAO) membranes. Here, nano-scale pores of controlled dimensions are formed through anodic oxidation of sputter deposited high purity Al films. The Al deposition conditions are controlled in order to modify the roughness and the grain size of the Al layers, as those parameters critically affect the subsequent pore formation during the anodization process. The anodization of the Al layers occurs in an electrochemical cell in H2SO4, H2C2O4 and H3PO4 solutions, in order to tune the AAO pore diameter and interpore distance.Following anodization, the fabricated AAO is selectively etched away in H2CrO4/H3PO4 mixtures, in order to reveal the underlying Al nanoscale dimples, which are present at the bottom of the pores. The light-trapping properties of these dimples are investigated as a function of their dimensions and ordering. The optical properties of the dimples are characterized mainly via reflection measurements, supported by laser ablation based measurements of the field enhancement [1]. The experiments are compared to FDTD calculations to further explain the mechanisms of light-trapping in these structures. The nanoscale dimples as light-trapping nanostructure are integrated into inverted P3HT/PCBM organic solar cell devices. The impact from the different dimple structures on the resulting power conversion efficiency of the devices is investigated and optimized for obtaining the highest device performance.[1] Fiutowski J., Maibohm C., Kjelstrup-Hansen J., and Rubahn H.-G. Appl. Phys. Lett. 98, 193117 (2011)

Mars Pathfinder obtained multispectral, elemental, magnetic, and physical measurements of soil and dust at the Sagan Memorial Station during the course of its 83 sol mission. We describe initial results from these measurements, concentrating on multispectral and elemental data, and use these data, along with previous Viking, SNC meteorite, and telescopic results, to help constrain the origin and evolution of Martian soil and dust. We find that soils and dust can be divided into at least eight distinct spectral units, based on parameterization of Imager for Mars Pathfinder (IMP) 400 to 1000 nm multispectral images. The most distinctive spectral parameters for soils and dust are the reflectivity in the red, the red/blue reflectivity ratio, the near-IR spectral slope, and the strength of the 800 to 1000 nm absorption feature. Most of the Pathfinder spectra are consistent with the presence of poorly crystalline or nanophase ferric oxide(s), sometimes mixed with small but varying degrees of well-crystalline ferric and ferrous phases. Darker soil units appear to be coarser-grained, compacted, and/or mixed with a larger amount of dark ferrous materials relative to bright soils. Nanophase goethite, akaganeite, schwertmannite, and maghemite are leading candidates for the origin of the absorption centered near 900 nm in IMP spectra. The ferrous component in the soil cannot be well-constrained based on IMP data. Alpha proton X-ray spectrometer (APXS) measurements of six soil units show little variability within the landing site and show remarkable overall similarity to the average Viking-derived soil elemental composition. Differences exist between Viking and Pathfinder soils, however, including significantly higher S and Cl abundances and lower Si abundances in Viking soils and the lack of a correlation between Ti and Fe in Pathfinder soils. No significant linear correlations were observed between IMP spectral properties and APXS elemental chemistry. Attempts at constraining the mineralogy of soils and dust using normative calculations involving mixtures of smectites and silicate and oxide minerals did not yield physically acceptable solutions. We attempted to use the Pathfinder results to constrain a number of putative soil and dust formation scenarios, including palagonitization and acid-fog weathering. While the Pathfinder soils cannot be chemically linked to the Pathfinder rocks by palagonitization, this study and McSween et al. [1999] suggest that palagonitic alteration of a Martian basaltic rock, plus mixture with a minor component of locally derived andesitic rock fragments, could be consistent with the observed soil APXS and IMP properties.

Organic solar cells (OSC), in spite of being a promising technology, still face challenges regarding large-scale fabrication. Although efficiencies of up to 12 % has been reached for small molecule OSC, their performance, both in terms of device efficiency and stability, is significantly reduced during up-scaling processes. The work presented here is focused on an approach towards up-scaling of small molecule based OSC with inverted device configuration. Bilayer OSC from Tetraphenyldibenzoperiflanthene (DBP) and Fullerenes (C70), as electron donor and acceptor respectively, with cell area ranging on a scale from a few mm2 to cm2, are produced by organic molecular beam deposition (OMBD). All the layers in the device are fabricated from a highly sophisticated vacuum cluster deposition system that includes electrode, interfacial layer and organic layer deposition in one high-vacuum deposition system. The work includes investigation of morphology and uniformity of the layers from atomic force microscopy (AFM) and optical spectroscopy investigations.

The organic bulk hetero-junction solar cell has remarkable advantages such as low cost, mechanical flexibility and simple process techniques.Recently, low-band gap photoactive materials have obtained a significant attention due to their potential to absorb a wider range of the solar spectrumto attain higher power conversion efficiencies. Many low-band gap photoactive materials, however, still show a relatively low external quantum efficiency of less than 60% [1]. One possible approach to improve the device performance is to increase the light absorption in the active layer. This may, amongst other approaches, be achieved by using nano- or micro-structures that trap light at specific wavelengths [2], or by using the localized surface plasmon resonance effect of metal nanoparticles in the devices. In this work, we theoretically studied planar polymer solar cell based on finite-difference time-domain approach. Also, we have optimized reference polymer solar cells with PTB7:PC70BM as active layer, using two different electron transport layers. The aim is to integrate Gold nanoparticles in the reference devices, and support the integration theoretically.

Organic nanostructures made from organic molecules such as para-hexaphenylene (p-6P) could form nanoscale components in future electronic and optoelectronic devices. However, the integration of such fragile nanostructures with the necessary interface circuitry such as metal electrodes for electrical connection continues to be a significant hindrance toward their large-scale implementation. Here, we demonstrate in situ–directed growth of such organic nanostructures between pre-fabricated contacts, which are source–drain gold electrodes on a transistor platform (bottom-gate) on silicon dioxide patterned by a combination of optical lithography and electron beam lithography. The dimensions of the gold electrodes strongly influence the morphology of the resulting structures leading to notably different electrical properties. The ability to control such nanofiber or nanoflake growth opens the possibility for large-scale optoelectronic device fabrication.

Curie temperatures indicating non-titaniferous magnetite are common in Icelandic basalts of all ages, especially Tertiary ones. Yet, microprobe analyses of such samples have shown high titanium in the magnetite. To resolve this paradox, and the mechanism at work, the magnetic mineral fraction of eight basalt samples with Js-T curves characteristic for pure magnetite was subjected to a multi-disciplinary analysis including Mössbauer spectroscopy and X-ray diffraction. In most of the samples titanium in the magnetite, as analysed with the microprobe, ranged between 16 and 28 wt.%, indicating submicroscopic solvus exsolution in the titanomagnetite, beyond the power of resolution for the microprobe. More unexpectedly in view of the reversible Js-T curves, Mössbauer spectroscopy showed appreciable proportion of maghemite in the magnetic fraction. A three-stage mechanism is proposed for the formation of the mineral assemblages observed: (1) limited high-temperature oxyexsolution; (2) solvus exsolution during low-temperature hydrothermal alteration; and (3) maghemitization of the magnetite. Finally, the maghemite may transform to hematite with time. It is concluded that maghemite is much more common in Icelandic rocks than hitherto believed.

Four samples of feroxyhite with different particle size have been studied by X-ray diffraction, Mossbauer spectroscopy, and electron microscopy. It is found that the magnetic properties change drastically as a function of particle size. The largest particles are ferro- or ferri-magnetic, but the smallest particles have only a very small net magnetic moment indicating that they are antiferromagnetic or spin-glasses.