Flame Synthesis of Complex Fluoride-Based Nanoparticles as Upconversion Phosphors

Recent improvements in precursor chemistry, reactor geometry and run conditions extend the manufacturing capability of traditional flame aerosol synthesis of oxide nanoparticles to metals, alloys and inorganic complex salts. As an example of a demanding composition, we demonstrate here the one-step flame synthesis of nanoparticles of a 4-element non-oxide phosphor for upconversion applications. The phosphors are characterized in terms of emission capability, phase purity and thermal phase evolution. The preparation of flame-made beta-NaYF4 with dopants of Yb, Tm or Yb, Er furthermore illustrates the now available nanoparticle synthesis tool boxes based on modified flamespray synthesis from our laboratories at ETH Zurich. Since scaling concepts for flame synthesis, including large-scale filtration and powder handling, have become available commercially, the development of industrial applications of complex nanoparticles of metals, alloys or most other thermally stable, inorganic compounds can now be considered a feasible alternative to traditional top-down manufacturing or liquid-intense wet chemistry.

The Role of Small and Medium-sized Centers for Territorial Development in Switzerland

This paper describes the role of small and medium-sized urban centers in Switzerland. Switzerland is a highly urbanized country where small and medium-sized urban centers play an important role in ensuring a balanced national urban system. Besides the four largest metropolitan regions （Zurich, Geneva, Basel and Bern）, small and medium-sized towns function as central places for a wider, often extensive hinterland. They provide opportunities for living and working and they connect rural and mountain regions to national and international networks. Using secondary statistics and a case study, the paper shows that small and medium-sized urban centers are home to significant concentrations of export-oriented industries. Firms in these value-adding secondary sectors are rooted in these places and benefit from strong local embeddedness while also being oriented towards global markets. Small and medium-sized urban centers also profit from their strong local identities. While these places face various challenges, they function as important pillars in creating a balanced regional development pattern. Swiss regional development policy follows the goal of polycentric spatial development and it employs various instruments that aim to ensure a balanced urban system.

When Shareholders choose not to Maximize Value: The Union Bank of Switzerland's 1994 Proxy Fight

The staid Union Bank of Switzerland, in a very close vote, won the support of its shareholders in its battle against an attempt by dissidents to guide the way the nation's biggest bank is run. The special shareholder vote, held in a packed Zurich sports hall, was one of the most keenly awaited events in recent Swiss financial histroy. The Wall Street Journal, November 23, 1994

A paradigm shift in mechanical biofilm management? Subgingival air polishing: a new way to improve mechanical biofilm management in the dental practice

In the past few years indications for the use of the air polishing technology have been expanded from supragingival use (airflow) to subgingival air polishing (perioflow) by the development of new low-abrasive glycine-based powders and devices with a subgingival nozzle. Several studies on the subgingival use of air polishing have been completed. On 7 June 2012, during the Europerio 7 Congress in Vienna, a consensus conference on mechanical biofilm management took place aiming to review the current evidence from the literature on the clinical relevance of the subgingival use of air polishing and to make practical recommendations for the clinician. Bernita Bush (Bern), Prof Johannes Einwag (Stuttgart), Prof Thomas Flemmig (Seattle), Carmen Lanoway (Munich), Prof Ursula Platzer (Hamburg), Prof Petra Schmage (Hamburg), Brigitte Schoeneich (Zurich), Prof Anton Sculean (Bern), Dr Clemens Walter (Basel), and Prof Jan Wennström (Gothenburg) discussed under the moderation of Klaus-Dieter Bastendorf and Christian Becker (both ADIC Association for Dental Infection Control) the available clinical studies to reach a consensus on available clinical evidence. This paper summarizes the main conclusions of the consensus conference and points to the clinical relevance of the findings for the dental practitioner.

Right ventricle best predicts the race performance in amateur ironman athletes

PURPOSE The ironman (IM) triathlon is a popular ultraendurance competition, consisting of 3.8 km of swimming, 180.2 km of cycling, and 42.2 km of running. The aim of this study was to investigate the predictors of IM race time, comparing echocardiographic findings, anthropometric measures, and training characteristics. METHODS Amateur IM athletes (ATHL) participating in the Zurich IM race in 2010 were included. Participants were examined the day before the race by a comprehensive echocardiographic examination. Moreover, anthropometric measurements were obtained the same day. During the 3 months before the race, each IM-ATHL maintained a detailed training diary. Recorded data were related to total IM race time. RESULTS Thirty-eight IM finishers (mean ± SD age = 38 ± 9 yr, 32 men [84%]) were evaluated. Total race time was 684 ± 89 min (mean ± SD). For right ventricular fractional area change (45% ± 7%, Spearman ρ = -0.33, P = 0.05), a weak correlation with race time was observed. Race performance exhibited stronger associations with percent body fat (15.2 ± 5.6%, ρ = 0.56, P = 0.001), speed in running training (11.7 ± 1.2 km · h(-1), ρ = -0.52, P = 0.002), and left ventricular myocardial mass index (98 ± 24 g · m(-2), ρ = -0.42, P = 0.009). The strongest association was found between race time and right ventricular end-diastolic area (22 ± 4 cm2, ρ = -0.64, P < 0.0001). In multivariate analysis, right ventricular end-diastolic area (β = -16.7, 95% confidence interval = -27.3 to -6.1, P = 0.003) and percent body fat (β = 6.8, 95% confidence interval = 1.1-12.6, P = 0.02) were independently predictive of IM race time. CONCLUSIONS In amateur IM-ATHL, RV end-diastolic area and percent body fat were independently related to race performance. RV end-diastolic area was the strongest predictor of race time. The role of the RV in endurance exercise may thus be more important than previously thought and needs to be further studied.

Schul-, Praxis- und habituelles Herrschaftswissen. Bildung ländlicher Eliten mit Blick auf die korporative Selbstverwaltung in der frühmodernen Schweiz (18. und 19. Jahrhundert)

Knowledge taught at schools, everyday skills and practical know-how. The relevancy of formation for local elites and the corporative self-government of Early Modern Switzerland Daniel Schläppi, Bern There were different kinds of rural elites in Early Modern Switzerland. The diverse parts of the country developed in very dissimilar ways politically and economically. Some regions were dominated by traditional types of agriculture. Some territories were ruled by major cities. In some of the rural Cantons like Uri, Schwyz, Unterwalden, Glarus and Zug a political elite took control over generations and practiced a cultural lifestyle comparable to the famous aristocracies in cities like Bern, Basel, Freiburg, Luzern, Solothurn and Zurich. Intense proto-industrialization formed a completely different sort of elite with strong affinities to industry and trade in other regions. Meanwhile the habitants of the valley close-by stayed farmers like their ancestors (like in Appenzell). In the most conservative parts of the country mercenary business played an important role till the very end of the Ancien Regime and even furthermore. In summery the variety of historical circumstances caused heterogeneous elites all over. Such socio-political diversity provoked a variety of educational backgrounds. I an academic understanding of the term we know only little about literacy in local rural elites. But there is strong evidence that a lively culture of reading and story-telling existed. This means that even simple countrymen seem to have been in possession of some books. The organisation and capacity of the school system is subject of controversial discussions among up to date researchers. The state of research makes us suppose that the people designed to political careers learned their essential skills not only in school but also in everyday life or on the job. Based on the fact that every community and countless public corporations managed their affairs by their own it’s evident that the local elite’s key-players had a large repertoire of techniques and skills like writing, calculating, strategic thinking or knowledge of oral tradition, old usage or important rituals. Unfortunately the historical actors left not that many sources that would tell us precisely how knowledge and know-how were transferred in former times. Hardly any private account books or common correspondence have been conserved. But a huge bunch of sources that originate from corporative self-administration shows us that most local elites were well-educated and had the necessary skills anyway. Above all other sources like for instance the «Topographische Beschreibungen» (topographic descriptions) that were initiated by the «Ökonomische Gesellschaft» of Berne since the sixties of the 18th century provide an insight into pre-modern classrooms. More important information on the historical formation-reality can be gained by the autobiography of the famous poor peasant Ulrich Bräker (1735‒1798) or some of the novels by Albert Bitzius (1797‒1854, better known as Jeremias Gotthelf). The pedagogic writings by Johann Heinrich Pestalozzi (1746‒1827) and the influences by his mentors Johann Rudolf Tschiffeli (1716‒1780) or Philipp Emanuel von Fellenberg (1771‒1884) are quite illustrative as well.

Origin of Minority Drug-Resistant HIV-1 Variants in Primary HIV-1 Infection

Background. Drug-resistant human immunodeficiency virus type 1 (HIV-1) minority variants (MVs) are present in some antiretroviral therapy (ART)–naive patients. They may result from de novo mutagenesis or transmission. To date, the latter has not been proven. Methods. MVs were quantified by allele-specific polymerase chain reaction in 204 acute or recent seroconverters from the Zurich Primary HIV Infection study and 382 ART-naive, chronically infected patients. Phylogenetic analyses identified transmission clusters. Results. Three lines of evidence were observed in support of transmission of MVs. First, potential transmitters were identified for 12 of 16 acute or recent seroconverters harboring M184V MVs. These variants were also detected in plasma and/or peripheral blood mononuclear cells at the estimated time of transmission in 3 of 4 potential transmitters who experienced virological failure accompanied by the selection of the M184V mutation before transmission. Second, prevalence between MVs harboring the frequent mutation M184V and the particularly uncommon integrase mutation N155H differed highly significantly in acute or recent seroconverters (8.2% vs 0.5%; P < .001). Third, the prevalence of less-fit M184V MVs is significantly higher in acutely or recently than in chronically HIV-1–infected patients (8.2% vs 2.5%; P = .004). Conclusions. Drug-resistant HIV-1 MVs can be transmitted. To what extent the origin—transmission vs sporadic appearance—of these variants determines their impact on ART needs to be further explored.

Joint Reprocessing of GPS, GLONASS and SLR

A joint reprocessing of GPS, GLONASS and SLR observations has been carried out at TU Dresden, TU Munich, AIUB and ETH Zurich. Common a priori models have been applied for the processing of all types of observation to ensure both consistent parameter estimates and the rigorous combination of microwave and optical measurements. Based on that reprocessing results, we evaluate the impact of adding GLONASS observations to the standard GPS data processing. In particular, changes in station position time series and day boundary overlaps of consecutive satellite arcs are analyzed. In addition, the GNSS orbits derived from microwave measurements are validated using independent SLR range measurements. Our SLR residuals indicate a significant improvement compared to previous results. Furthermore, we evaluate the performance of our high-rate (30s) combined GNSS satellite clocks and discuss associated zero-difference phase residuals.

Lake sediments as natural seismographs: A compiled record of Late Quaternary earthquakes in Central Switzerland and its implication for Alpine deformation

Central Switzerland lies tectonically in an intraplate area and recurrence rates of strong earthquakes exceed the time span covered by historic chronicles. However, many lakes are present in the area that act as natural seismographs: their continuous, datable and high-resolution sediment succession allows extension of the earthquake catalogue to pre-historic times. This study reviews and compiles available data sets and results from more than 10 years of lacustrine palaeoseismological research in lakes of northern and Central Switzerland. The concept of using lacustrine mass-movement event stratigraphy to identify palaeo-earthquakes is showcased by presenting new data and results from Lake Zurich. The Late Glacial to Holocene mass-movement units in this lake document a complex history of varying tectonic and environmental impacts. Results include sedimentary evidence of three major and three minor, simultaneously triggered basin-wide lateral slope failure events interpreted as the fingerprints of palaeoseismic activity. A refined earthquake catalogue, which includes results from previous lake studies, reveals a non-uniform temporal distribution of earthquakes in northern and Central Switzerland. A higher frequency of earthquakes in the Late Glacial and Late Holocene period documents two different phases of neotectonic activity; they are interpreted to be related to isostatic post-glacial rebound and relatively recent (re-)activation of seismogenic zones, respectively. Magnitudes and epicentre reconstructions for the largest identified earthquakes provide evidence for two possible earthquake sources: (i) a source area in the region of the Alpine or Sub-Alpine Front due to release of accumulated north-west/south-east compressional stress related to an active basal thrust beneath the Aar massif; and (ii) a source area beneath the Alpine foreland due to reactivation of deep-seated strike-slip faults. Such activity has been repeatedly observed instrumentally, for example, during the most recent magnitude 4.2 and 3.5 earthquakes of February 2012, near Zug. The combined lacustrine record from northern and Central Switzerland indicates that at least one of these potential sources has been capable of producing magnitude 6.2 to 6.7 events in the past.

Loss of DAXX and ATRX are associated with chromosome instability and reduced survival of patients with pancreatic neuroendocrine tumors

BACKGROUND & AIMS Sporadic pancreatic neuroendocrine tumors (pNETs) are rare and genetically heterogeneous. Chromosome instability (CIN) has been detected in pNETs from patients with poor outcomes, but no specific genetic factors have been associated with CIN. Mutations in death domain-associated protein gene (DAXX) or ATR-X gene (ATRX) (which both encode proteins involved in chromatin remodeling) have been detected in 40% of pNETs, in association with activation of alternative lengthening of telomeres. We investigated whether loss of DAXX or ATRX, and consequent alternative lengthening of telomeres, are related to CIN in pNETs. We also assessed whether loss of DAXX or ATRX is associated with specific phenotypes of pNETs. METHODS We collected well-differentiated primary pNET samples from 142 patients at the University Hospital Zurich and from 101 patients at the University Hospital Bern (both located in Switzerland). Clinical follow-up data were obtained for 149 patients from general practitioners and tumor registries. The tumors were reclassified into 3 groups according to the 2010 World Health Organization classification. Samples were analyzed by immunohistochemistry and telomeric fluorescence in situ hybridization. We correlated loss of DAXX, or ATRX, expression, and activation of alternative lengthening of telomeres with data from comparative genomic hybridization array studies, as well as with clinical and pathological features of the tumors and relapse and survival data. RESULTS Loss of DAXX or ATRX protein and alternative lengthening of telomeres were associated with CIN in pNETs. Furthermore, loss of DAXX or ATRX correlated with tumor stage and metastasis, reduced time of relapse-free survival, and decreased time of tumor-associated survival. CONCLUSIONS Loss of DAXX or ATRX is associated with CIN in pNETs and shorter survival times of patients. These results support the hypothesis that DAXX- and ATRX-negative tumors are a more aggressive subtype of pNET, and could lead to identification of strategies to target CIN in pancreatic tumors.

Improving a gas ion source for C-14 AMS

For more than 4 years, gaseous samples of 1-50 mu g carbon have been routinely measured with the gas ion source of the small AMS (Accelerator Mass Spectrometer) facility MICADAS (Mini CArbon DAting System) at ETH Zurich. The applied measurement technique offers a simple and fast way of C-14 measurements without the need of sample graphitization. A major drawback of gaseous C-14 measurements, however, is the relatively low negative ion current, which results in longer measurement times and lower precision compared to graphitized samples. In December 2009, a new, improved Cs sputter ion source was installed at MICADAS and we began to optimize conditions for the measurement of gaseous samples. C-12(-) currents from the new ion source were improved from initially 3 to 12-15 mu A for routine measurements and the negative ion yield was increased by a factor of 2, reaching 8 on average during routine operation. Moreover, the new measurement settings enable a doubled CO2 flow, thus substantially reducing measurement times. The achieved performance allows closing the sample size gap between gaseous and solid samples and makes the gas ion source a promising tool for dating with a measurement precision of 5 parts per thousand on samples as small as 50 mu g carbon. (C) 2012 Elsevier B.V. All rights reserved.

A versatile gas interface for routine radiocarbon analysis with a gas ion source

In 2010 more than 600 radiocarbon samples were measured with the gas ion source at the MIni CArbon DAting System (MICADAS) at ETH Zurich and the number of measurements is rising quickly. While most samples contain less than 50 mu g C at present, the gas ion source is attractive as well for larger samples because the time-consuming graphitization is omitted. Additionally, modern samples are now measured down to 5 per-mill counting statistics in less than 30 min with the recently improved gas ion source. In the versatile gas handling system, a stepping-motor-driven syringe presses a mixture of helium and sample CO2 into the gas ion source, allowing continuous and stable measurements of different kinds of samples. CO2 can be provided in four different ways to the versatile gas interface. As a primary method. CO2 is delivered in glass or quartz ampoules. In this case, the CO2 is released in an automated ampoule cracker with 8 positions for individual samples. Secondly, OX-1 and blank gas in helium can be provided to the syringe by directly connecting gas bottles to the gas interface at the stage of the cracker. Thirdly, solid samples can be combusted in an elemental analyzer or in a thermo-optical OC/EC aerosol analyzer where the produced CO2 is transferred to the syringe via a zeolite trap for gas concentration. As a fourth method, CO2 is released from carbonates with phosphoric acid in septum-sealed vials and loaded onto the same trap used for the elemental analyzer. All four methods allow complete automation of the measurement, even though minor user input is presently still required. Details on the setup, versatility and applications of the gas handling system are given. (C) 2012 Elsevier B.V. All rights reserved.

Transport of 234U in the Opalinus Clay on centimetre to decimetre scales

The Opalinus Clay formation in North Switzerland is a potential host rock for a deep underground radioactive waste repository. The distribution of U-238, U-234 and Th-230 was studied in rock samples of the Opalinus Clay from an exploratory borehole at Benken (Canton of Zurich) using MC-ICP-MS. The aim of U-234 was to assess the in situ, long-term migration behaviour in this rock. Very low hydraulic conductivities of the Opalinus Clay, reducing potential of the pore water and its chemical equilibrium with the host rock are expected to render both U-238 and Th-230 immobile. If U is heterogeneously distributed in the Opalinus Clay, gradients in the supply of U-234 from the rock matrix to the pore water by the decay of U-238 will be established. Diffusive redistribution separates U-234 from its immobile parent U-238 resulting in bulk rock U-234/U-238 activity disequilibria. These may provide a means of estimating the mobility of U-234 in the rock if the diffusion rate of U-234 is significant compared to its decay rate. Sampling was carried out on two scales. Drilling of cm-spaced samples from the drill-core was done to study mobility over short distances and elucidate possible small-scale lithological control. Homogenized 25-cm-long portions of a 2-m-long drill-core section were prepared to provide information on transport over a longer distance. Variations in U and/or Th content on the cm-scale between clays and carbonate-sandy layers are revealed by beta-scanning, which shows that the (dominant) clay is richer in both elements. Samples were digested using aqua regia followed by total HF dissolution, yielding two fractions. in all studied samples U was found to be concentrated in the HF digestion fraction. It has a high U/Th ratio and a study by SEM-EDS points to sub-mu m up to several mu m in size zircon grains as the main U-rich phase. This fraction consistently has U-234/U-238 activity ratios below unity. The minute zircon grains constitute the major reservoir of U in the rock and act as constant rate suppliers of U-234 into the rock matrix and the pore water. The aqua regia leach fraction was found to be enriched in Th, and complementary to the HF fraction, having U-234/U-238 activity ratios above unity. It is believed that these U activity ratios reflect the surplus of having U-234 delivered from the zircon grains. Some cm-spaced samples show bulk rock U-234/U-238 activity ratios that are markedly out of equilibrium. In most of them a striking negative correlation between the total U content and the bulk rock U-234/U-238 activity ratios is observed. This is interpreted to indicate net U-234 transfer from regions of higher supply of U-234 towards those of lower supply which is, in most cases, equivalent to transfer from clayey towards carbonate/sandy portions of the rock. In contrast, the 25 cm averaged samples all have uniform bulk rock U-234/U-238 activity ratios in equilibrium, indicating U immobility in the last 1-1.5 Ma on this spatial scale. It is concluded that the small-scale lithological variations which govern U spatial distribution in the Opalinus Clay are the major factor determining U-234 in situ supply rates, regulating its diffusive fluxes and controlling the observed bulk rock U-234/U-238 activity ratios. A simple box-model is presented to simulate the measured bulk rock U-234/U-238 activity ratios and to give an additional insight into the studied system. (C) 2008 Elsevier Ltd. All rights reserved.