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A prospective observational study comparing mechanical power density (MP normalized to dynamic compliance) with traditional spontaneous breathing indexes (e.g., predicted body weight normalized tidal volume [VT/PBW], rapid shallow breathing index [RSBI], or the integrative weaning index [IWI]) for predicting prolonged weaning failure in 140 tracheotomized patients. We assessed the diagnostic accuracy of these indexes at the start and end of the weaning procedure using ROC curve analysis, expressed as the area under the receiver operating characteristic curve (AUROC). Weaning failure occurred in 41 out of 140 patients (29%), demonstrating significantly higher MP density (6156 cmH2O2/min [4402–7910] vs. 3004 cmH2O2/min [2153–3917], P < 0.01), lower spontaneous VT/PBW (5.8 mL*kg−1 [4.8–6.8] vs. 6.6 mL*kg−1 [5.7–7.9], P < 0.01) higher RSBI (68 min−1*L−1 [44–91] vs. 55 min−1*L−1 [41–76], P < 0.01) and lower IWI (41 L2/cmH2O*%*min*10−3 [25–72] vs. 71 L2/cmH2O*%*min*10-3 [50–106], P < 0.01) and at the end of weaning. MP density was more accurate at predicting weaning failures (AUROC 0.91 [95%CI 0.84–0.95]) than VT/PBW (0.67 [0.58–0.74]), RSBI (0.62 [0.53–0.70]), or IWI (0.73 [0.65–0.80]), and may help clinicians in identifying patients at high risk for long-term ventilator dependency. [ABSTRACT FROM AUTHOR]

Within the Research Cluster of Excellence "The Fuel Science Center" at RWTH Aachen University, the production and application of new fuels from bio-based carbon feedstocks and CO2 with hydrogen from renewable electricity generation is being investigated. In this study, the storage and oxidation of ethanol, 1-butanol, 2-butanone, cyclopentanone, and cyclopentane as well as two blends thereof on a series production Pt–Pd/Al2O3 oxidation catalyst were investigated. Hydrocarbon (HC) storage and temperature-programmed surface reaction (TPSR) experiments were carried out to analyze their adsorption and desorption behavior. In addition, the individual HCs and both blends were investigated using Diffuse Reflectance Infrared Fourier Transform Spectroscopy (TP-DRIFTS). In general, all oxygenated HCs are adsorbed more strongly than cyclopentane due to their higher polarity. Interestingly, it could be observed that the two different blends [blend 1: ethanol (50 mol %), 2-butanone (21 mol %), cyclopentanone (14 mol %) and cyclopentane (15 mol %); blend 2: 1-butanol (45 mol %), ethanol (29 mol %) and cyclopentane (27 mol %)] exhibit a different storage behavior compared to the single hydrocarbons. It was shown that the presence of 1-butanol and cyclopentane in blend 2 strongly inhibits the oxidation of ethanol. As a result, the ethanol light-off temperature was increased by at least 100 K. A difference was also found in the storage behavior of cyclopentane. While no significant storage could be detected in the pure compound experiment, the experiments with both mixtures showed a larger amount stored. The presence of adsorbed species of the hydrocarbons and their corresponding reaction products has been demonstrated and gives an insight into the storage mechanism of blends. [ABSTRACT FROM AUTHOR]

Perovskite-type transition metal (TM) oxides are effective catalysts in oxidation and decomposition reactions. Yet, the effect of compositional variation on catalytic efficacy is not well understood. The present analysis of electronic characteristics of B-site substituted LaCoO3 derivatives via in situ X-ray absorption spectroscopy (XAS) establishes correlations of electronic parameters with reaction rates: TM t2g and eg orbital occupancy yield volcano-type or non-linear correlations with NO oxidation, CO oxidation and N2O decomposition rates. Covalent O 2p-TM 3d interaction, in ultra-high vacuum, is a linear descriptor for reaction rates in NO oxidation and CO oxidation, and for N2O decomposition rates in O2 presence. Covalency crucially determines the ability of the catalytically active sites to interact with surface species during the kinetically relevant step of the reaction. The nature of the kinetically relevant step and of surface species involved lead to the vast effect of XAS measurement conditions on the validity of correlations. Design of efficient catalysts requires understanding the decisive electronic parameters for catalytic efficacy and their dependence on elemental composition. Here, the authors report covalency as suitable descriptor of perovskite-type transition metal oxides as chemo-catalysts. [ABSTRACT FROM AUTHOR]

Within the Research Cluster of Excellence "Tailor-Made Fuels from Biomass" at RWTH Aachen University, novel fuels from biomass for internal combustion engines are investigated. The new fuels tend to soot less, which allows to increase exhaust gas recirculation for reduction of nitrogen oxides (NOx) emissions. This increases the emissions of unburnt hydrocarbons (HC), while the composition of the HC emissions changes because of the changed fuel composition. The impact of 16 different oxygen-free and oxygenated hydrocarbons (1-octanol, di-n-butyl ether (DNBE), 2-butanone and ethanol as examples for bio-derived fuels; toluene and n-heptane as examples for conventional fuels' components; propane, propene, ethane, ethene, ethyne, methane, n-butane, isobutane, n-pentane and 2-propanol as HC known to be in exhaust gases) on a series production Pt-Pd/Al2O3 oxidation catalyst on a cordierite substrate has been investigated regarding adsorption and temperature programmed oxidation (TPO). In general, due to higher polarity oxygenated HC are stronger adsorbed than oxygen-free ones. For 1-octanol, an extraordinary high adsorption could be observed associated with vigorous exothermal oxidation reaction during TPO. Additionally, the temperature programmed desorption of 1-octanol and ethanol has been investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy (TP-DRIFTS). Adsorbed alcohol species as well as oxidized products were demonstrated to be present. [ABSTRACT FROM AUTHOR]

Spinel-type lithium manganese oxides are considered as promising cathode materials for lithium-ion batteries. Trace amounts of Li2MnO3 usually occur as a secondary phase in lithium-manganese spinels in the common high-temperature, solid-state synthesis, affecting the overall Li-Mn stoichiometry in the spinel phase and thereby the electrochemical performance. However, the formation of Li2MnO3 lower than 1 wt.% can hardly be quantified by the conventional analytical techniques. In this work, we synthesized lithium-manganese spinels with different Li/Mn molar ratios and demonstrate that electron paramagnetic resonance (EPR) enables quantifying trace amounts of Li2MnO3 below 10−2 wt.% in the synthesized products. The results reveal that the formation of Li2MnO3 secondary phase is favored by lithium excess in the synthesis. Based on the quantitative evaluation of the EPR data, precise determining Li-Mn stoichiometry in the spinel phase in Li1+xMn2−xO4 materials can be assessed. Accordingly, it is possible to estimate the amount of lithium on 16d-sites in the Li-rich manganese spinels. [ABSTRACT FROM AUTHOR]

Gold nanoparticles (AuNPs) have been extensively explored in biomedical applications, for example as drug carriers, contrast agents, or therapeutics. However, AuNP can exhibit cytotoxic profile, when the size is below 2 nm (ultrasmall AuNP; usAuNP) and when the stabilizing ligands allow for access to the gold surface either for the direct interaction with biomolecules or for catalytic activity of the unshielded gold surface. Furthermore, usAuNP exhibits significantly different biodistribution and enhanced circulation times compared to larger AuNP. This review gives an overview about the synthesis and the physico-chemical properties of usAuNP and, thereby, focusses on 1.4 nm sized AuNP, which are derived from the compound Au(PPh)Cl and which are the most intensively studied usAuNP in the field. This part is followed by a summary of the toxic properties of usAuNP, which include in vitro cytotoxicity tests on different cell lines, electrophysiological tests following FDA guidelines as well as studies on antibacterial effects. Finally, the biodistribution and pharmacokinetics of ultrasmall AuNP are discussed and compared to the properties of more biocompatible, larger AuNP. [ABSTRACT FROM AUTHOR]

Purpose: Aerosol particle deposition in the human nasal cavity is of high interest in particular for intranasal central nervous system (CNS) drug delivery via the olfactory cleft. The objective of this study was the development and comparison of a numerical and experimental model to investigate various parameters for olfactory particle deposition within the complex anatomical nasal geometry. Methods: Based on a standardized nasal cavity, a computational fluid and particle dynamics (CFPD) model was developed that enables the variation and optimization of different parameters, which were validated by in vitro experiments using a constructed rapid-prototyped human nose model. Results: For various flow rates (5 to 40 l/min) and particle sizes (1 to 10 μm), the airflow velocities, the calculated particle airflow patterns and the particle deposition correlated very well with the experiment. Particle deposition was investigated numerically by varying particle sizes at constant flow rate and vice versa assuming the particle size distribution of the used nebulizer. Conclusions: The developed CFPD model could be directly translated to the in vitro results. Hence, it can be applied for parameter screening and will contribute to the improvement of aerosol particle deposition at the olfactory cleft for CNS drug delivery in particular for biopharmaceuticals. [ABSTRACT FROM AUTHOR]

Group III nitrides are promising materials for light emitting diodes (LEDs). The occurrence of structural defects strongly affects the efficiency of these LEDs. We investigate the optical properties of basal plane stacking faults (BFSs), and the assignment of specific spectral features to distinct defect types by direct correlation of localized emission bands measured by cathodoluminescence in a scanning electron microscope with defects found in high resolution (scanning) transmission electron microscopy and electron beam induced current at identical sample spots. Thus, we are able to model the electronic structure of BSFs addressing I1, I2, and E type BSFs in GaN and AlGaN with low Al content. We find hints that BSFs in semipolar AlGaN layers cause local changes of the Al content, which strongly affects the usability of AlGaN as an electron blocking layer in nitride based LEDs. [ABSTRACT FROM AUTHOR]

DNA-functionalized gold nanoparticles (AuNP-DNA) were hybridized with complementary di- N-acetyllactosamine-( di-LacNAc, [3Gal(β1-4)GlcNAc(β1-]2)-modified oligonucleotides to form glycol-functionalized particles, AuNP-DNA- di-LacNAc. While AuNP-DNA are known to be taken up by cells via scavenger receptors, glycol-functionalized particles have shown to be taken up via asialoglycoprotein receptors (ASGP-R). In this work, the interaction of these new particles with HepG2 cells was analyzed, which express scavenger receptors class B type I (SR-BI) and ASGP-R. To study the contribution of these receptors as potential mediators for cellular uptake, receptor-blocking experiments were performed with d-lactose, a ligand for ASGP-R, Fucoidan, a putative ligand for SR-BI, and a SR-BI blocking antibody. Labeling with Cy5-modified DNA ligands enabled us to monitor the particle uptake by confocal fluorescence microscopy and flow cytometry, in order to discriminate the two putative pathways by competitive binding studies. While SR-BI-antibody and d-lactose had no inhibiting effects on particle uptake Fucoidan led to a complete inhibition. Thus, a receptor-mediated uptake by the two receptors studied could not be proven and therefore other uptake mechanisms have to be considered. [ABSTRACT FROM AUTHOR]

The review describes the workflow of a high-throughput screening process for the rapid identification of new and improved gas sensor materials. Multiple nanoparticulate metal oxides were synthesized via the polyol method, and material diversity was achieved by volume and/or surface doping. The resulting materials were applied as thick films on multielectrode substrates to serve as chemiresistors. This high-throughput approach including automated preparation, complex impedance measurements, and evaluation procedures enables reproducible measurements and their visual representation. Selected examples demonstrate the state of the art for applying high-throughput impedance spectroscopy in search of new sensitive and selective gas sensing materials as well as in analyzing structure–property relations. [ABSTRACT FROM AUTHOR]

The present study relates to the applicability of silicon nanoparticles as basic component in printing inks for the fabrication of printable electronic devices. It is systematically investigated, how the surface functionalization of silicon nanoparticles with 1-alkenes affects the electrical properties of thin films made of them. Therefore, films of as-prepared silicon nanoparticles with a size of 42 nm as well as freshly etched ones, both terminated with hydrogen, are compared with films of silicon nanoparticles functionalized with n-octene, n-dodecene, allylmercaptan, and allylamine, respectively. It is found, that the activation energy of the electron transport through the films is in the range of 0.5 eV and scales with the polarity of the functionalization. [ABSTRACT FROM AUTHOR]

Experimental studies on metaphyseal fractures are rare and do not control the biomechanical conditions in the healing zone. This study aimed to develop an improved experimental model, which characterizes and controls the biomechanical condition in the fracture gap of a metaphyseal fracture. A partial osteotomy model in the distal femur of the sheep was developed. The osteotomy was located in the region of the trochlea groove. The osteotomy gap was 3 mm wide. The retro-patellar force acting on the joint in vivo causes a bending of the trochlea resulting in a narrowing of the osteotomy gap. To limit and control this interfragmentary movement, stainless steel plates of various thicknesses were implanted into the osteotomy gap. Forces acting on the trochlea were analyzed and a load-deflection curve of the model was determined in vitro. A pilot study on two sheep was performed using the new model with two different interfragmentary movements of 0.3 or 1 mm. Eight weeks, post-operatively, the sheep were sacrificed and undecalcified histology was performed. The biomechanical analysis of the joint forces and the in vitro load-deflection behavior of the trochlea revealed that the forces acting on the trochlea were high enough to cause an interfragmentary movement of 1 mm in the osteotomy gap. This was confirmed by an X-ray of the sheep, which showed a closing of the proximal osteotomy gap under weight-bearing conditions. The histological section revealed no external callus formation. The sheep with the 0.3 mm interfragmentary movement showed almost complete bridging of the osteotomy gap with woven bone whereas the sheep with the 1 mm interfragmentary movement exhibited new bone formation only at the borderline of the osteotomy but larger areas with connective tissue or even fibrous cartilage in the center of the gap. This metaphyseal bone-healing model provides defined and adjustable biomechanical conditions. The histological images demonstrated intramembranous and endochondral bone healing in the osteotomy gap without callus formation. The model therefore seems appropriate to study metaphyseal bone healing under differing mechanical conditions. [ABSTRACT FROM AUTHOR]

Fracture repair, which aims at regaining the functional competence of a bone, is a complex and multifactorial process. For the success of fracture repair biology and mechanics are of immense importance. The biological and mechanical environments must be compatible with the processes of cell and tissue proliferation and differentiation. The biological environment is characterized by the vascular supply and by many biochemical components, the biochemical milieu. A good vascular supply is a prerequisite for the initiation of the fracture repair process. The biochemical milieu involves complex interactions among local and systemic regulatory factors such as growth factors or cytokines. The mechanical environment is determined by the local stress and strain within the fracture. However, the local stress and strain is not accessible, and the mechanical environment, therefore, is described by global mechanical factors, e.g., gap size or interfragmentary movement. The relationship between local stress and strain and the global mechanical factors can be obtained by numerical models (Finite Element Model). Moreover, there is considerable interaction between biological factors and mechanical factors, creating a biomechanical environment for the fracture healing process. The biomechanical environment is characterized by osteoblasts and osteocytes that sense the mechanical signal and express biological markers, which effect the repair process. This review will focus on the effects of biomechanical factors on fracture repair as well as the effects of age and osteoporosis. [ABSTRACT FROM AUTHOR]

Epiphytes are often assumed to influence the microclimatic conditions of the tree crowns that they inhabit. In order to quantify this notion, we measured the parameters "temperature" (of the substrate surface and the boundary layer of air above it), "evaporative drying rate" and "evapotranspiration" at various locations within tree crowns with differing epiphyte assemblages. The host tree species was Annona glabra, which was either populated by one of three epiphyte species ( Dimerandra emarginata, Tillandsia fasciculata, or Vriesea sanguinolenta) or was epiphyte-free. We found that during the hottest and driest time of day, microsites in the immediate proximity of epiphytes had significantly lower temperatures than epiphyte-bare locations within the same tree crown, even though the latter were also shaded by host tree foliage or branches. Moreover, water loss through evaporative drying at microsites adjacent to epiphytes was almost 20% lower than at exposed microsites. We also found that, over the course of several weeks, the evapotranspiration in tree crowns bearing epiphytes was significantly lower than in trees without epiphytes. Although the influence of epiphytes on temperature extremes and evaporation rates is relatively subtle, their mitigating effect could be of importance for small animals like arthropods inhabiting an environment as harsh and extreme as the tropical forest canopy. [ABSTRACT FROM AUTHOR]

The arthropod activity in the upper and the lower zone of nine emergent oak trees (genus Quercus) of a submontane forest in Sabah, Borneo, Malaysia, was investigated by using flight interception traps, yellow colour traps, and arboreal pitfall traps. Number of arthropods did not differ significantly between the upper and the lower region of the tree crowns. Nevertheless, the results reveal significant differences in the abundances of several arthropod groups between the two zones. In the lower part of the oak crowns Homoptera and ants (mostly alates) were sampled in higher numbers, whereas the upper zone was dominated by Diptera and Hymenoptera (ants excluded). Beetles and most other groups showed no significant differences in abundance between the lower and upper zone of the oak trees. Thus, the arthropods of the investigated community are not evenly distributed. The arthropod community in tree crowns, which often has been treated as a homogenous unit, is in fact divided into subunits formed by differently composed arthropod assemblages. [ABSTRACT FROM AUTHOR]

The Upper Palaeolithic double burial of newborns and the single burial of a ca. 3-month-old infant uncovered at the Gravettian site of Krems-Wachtberg, Austria, are of paramount importance given the rarity of immature human remains from this time. Genome-wide ancient DNA shows that the male infants of the double grave are the earliest reported case of monozygotic twins, while the single grave´s individual was their 3rd-degree male relative. We assessed the individuals´ age at death by applying histological and µCT inspection of the maxillary second incisors (i2) in conjunction with C- and N-isotope ratios and Barium (Ba) intake as biomarker for breastfeeding. The results show that the twins were full-term newborns, and that while individual 2 died at birth, individual 1 survived for about 50 days. The findings show that Gravettian mortuary behaviour also included re-opening of a grave and manipulation of its layout and content. Maria Teschler-Nicola et al. use ancient DNA sequencing to report the earliest known case of human monozygotic twins found in a previously discovered Upper Palaeolithic burial site. Using bioanthropological and archaeological techniques, they also find that the twins were full-term newborns and that ancient mortuary behavior included re-opening of grave sites to bury related individuals together. [ABSTRACT FROM AUTHOR]

The article discusses the diverse fabrication method used to decorate nanostructures which are composed of semiconducting, organic, and metallic materials. It states that the nanostructures are utilized as building blocks for complex structures' self-assembly. It mentions that the decoration of the materials based from nanoparticles control its spacing and the balance of the assemblies. Moreover, designing nanostructures can be achieved through DNA linkers which have oglionucleotide strands.

Decorations on the bodies of newborns indicate that they were probably important in their community.Several adult graves from the Stone Age (Upper Palaeolithic period) have been found but child burials seem to be rare, which has prompted discussion about whether this apparently different treatment of infants could be significant. Here we describe two recently discovered infant burials from this period at Krems-Wachtberg in Lower Austria, in which the bodies were covered with red ochre and decorated with ornaments and were therefore probably ritually buried. These findings indicate that even newborns were considered to be full members of these hunter−gatherer communities about 27,000 years ago. [ABSTRACT FROM AUTHOR]