Measurement of the K + - pi + pi - e + - (-) v e form factors and of the pi pi scattering length a 0 0

The quark condensate is a fundamental free parameter of Chiral Perturbation Theory ($chi PT$), since it determines the relative size of the mass and momentum terms in the power expansion. In order to confirm or contradict the assumption of a large quark condensate, on which $chi PT$ is based, experimental tests are needed. In particular, the $S$-wave $pipi$ scattering lengths $a_0^0$ and $a_0^2$ can be predicted precisely within $chi PT$ as a function of this parameter and can be measured very cleanly in the decay $K^{pm} to pi^{+} pi^{-} e^{pm} stackrel{mbox{tiny(---)}}{nu_e}$ ($K_{e4}$). About one third of the data collected in 2003 and 2004 by the NA48/2 experiment were analysed and 342,859 $K_{e4}$ candidates were selected. The background contamination in the sample could be reduced down to 0.3% and it could be estimated directly from the data, by selecting events with the same signature as $K_{e4}$, but requiring for the electron the opposite charge with respect to the kaon, the so-called ``wrong sign'' events. This is a clean background sample, since the kaon decay with $Delta S=-Delta Q$, that would be the only source of signal, can only take place through two weak decays and is therefore strongly suppressed. The Cabibbo-Maksymowicz variables, used to describe the kinematics of the decay, were computed under the assumption of a fixed kaon momentum of 60 GeV/$c$ along the $z$ axis, so that the neutrino momentum could be obtained without ambiguity. The measurement of the form factors and of the $pipi$ scattering length $a_0^0$ was performed in a single step by comparing the five-dimensional distributions of data and MC in the kinematic variables. The MC distributions were corrected in order to properly take into account the trigger and selection efficiencies of the data and the background contamination. The following parameter values were obtained from a binned maximum likelihood fit, where $a_0^2$ was expressed as a function of $a_0^0$ according to the prediction of chiral perturbation theory: f'_s/f_s = 0.133+- 0.013(stat)+- 0.026(syst) f''_s/f_s = -0.041+- 0.013(stat)+- 0.020(syst) f_e/f_s = 0.221+- 0.051(stat)+- 0.105(syst) f'_e/f_s = -0.459+- 0.170(stat)+- 0.316(syst) tilde{f_p}/f_s = -0.112+- 0.013(stat)+- 0.023(syst) g_p/f_s = 0.892+- 0.012(stat)+- 0.025(syst) g'_p/f_s = 0.114+- 0.015(stat)+- 0.022(syst) h_p/f_s = -0.380+- 0.028(stat)+- 0.050(syst) a_0^0 = 0.246+- 0.009(stat)+- 0.012(syst)}+- 0.002(theor), where the statistical uncertainty only includes the effect of the data statistics and the theoretical uncertainty is due to the width of the allowed band for $a_0^2$.

Synthesis and characterization of metal-chalcogenide MQ 2-Nanoparticles (M = Mo, W, Zr; Q = S, O)

Here, we present the adaptation and optimization of (i) the solvothermal and (ii) the metal-organic chemical vapor deposition (MOCVD) approach as simple methods for the high-yield synthesis of MQ2 (M=Mo, W, Zr; Q = O, S) nanoparticles. Extensive characterization was carried out using X-ray diffraction (XRD), scanning and transmission electron micros¬copy (SEM/TEM) combined with energy dispersive X-ray analysis (EDXA), Raman spectroscopy, thermal analyses (DTA/TG), small angle X-ray scattering (SAXS) and BET measurements. After a general introduction to the state of the art, a simple route to nanostructured MoS2 based on the decomposition of the cluster-based precursor (NH4)2Mo3S13∙xH2O under solvothermal conditions (toluene, 653 K) is presented. Solvothermal decomposition results in nanostructured material that is distinct from the material obtained by decomposition of the same precursor in sealed quartz tubes at the same temperature. When carried out in the presence of the surfactant cetyltrimethyl¬ammonium bromide (CTAB), the decomposition product exhibits highly disordered MoS2 lamellae with high surface areas. The synthesis of WS2 onion-like nanoparticles by means of a single-step MOCVD process is discussed. Furthermore, the results of the successful transfer of the two-step MO¬CVD based synthesis of MoQ2 nanoparticles (Q = S, Se), comprising the formation of amorphous precursor particles and followed by the formation of fullerene-like particles in a subsequent annealing step to the W-S system, are presented. Based on a study of the temperature dependence of the reactions a set of conditions for the formation of onion-like structures in a one-step reaction could be derived. The MOCVD approach allows a selective synthesis of open and filled fullerene-like chalcogenide nanoparticles. An in situ heating stage transmission electron microscopy (TEM) study was employed to comparatively investigate the growth mechanism of MoS2 and WS2 nanoparticles obtained from MOCVD upon annealing. Round, mainly amorphous particles in the pristine sample trans¬form to hollow onion-like particles upon annealing. A significant difference between both compounds could be demonstrated in their crystallization conduct. Finally, the results of the in situ hea¬ting experiments are compared to those obtained from an ex situ annealing process under Ar. Eventually, a low temperature synthesis of monodisperse ZrO2 nanoparticles with diameters of ~ 8 nm is introduced. Whereas the solvent could be omitted, the synthesis in an autoclave is crucial for gaining nano-sized (n) ZrO2 by thermal decomposition of Zr(C2O4)2. The n-ZrO2 particles exhibits high specific surface areas (up to 385 m2/g) which make them promising candidates as catalysts and catalyst supports. Co-existence of m- and t-ZrO2 nano-particles of 6-9 nm in diameter, i.e. above the critical particle size of 6 nm, demonstrates that the particle size is not the only factor for stabilization of the t-ZrO2 modification at room temperature. In conclusion, synthesis within an autoclave (with and without solvent) and the MOCVD process could be successfully adapted to the synthesis of MoS2, WS2 and ZrO2 nanoparticles. A comparative in situ heating stage TEM study elucidated the growth mechanism of MoS2 and WS2 fullerene-like particles. As the general processes are similar, a transfer of this synthesis approach to other layered transition metal chalcogenide systems is to be expected. Application of the obtained nanomaterials as lubricants (MoS2, WS2) or as dental filling materials (ZrO2) is currently under investigation.

Modeling and simulation of a synthetic genetic circuit that implements a multicelled behavior in a growing microcolony of E. coli

Synthetic Biology is a relatively new discipline, born at the beginning of the New Millennium, that brings the typical engineering approach (abstraction, modularity and standardization) to biotechnology. These principles aim to tame the extreme complexity of the various components and aid the construction of artificial biological systems with specific functions, usually by means of synthetic genetic circuits implemented in bacteria or simple eukaryotes like yeast. The cell becomes a programmable machine and its low-level programming language is made of strings of DNA. This work was performed in collaboration with researchers of the Department of Electrical Engineering of the University of Washington in Seattle and also with a student of the Corso di Laurea Magistrale in Ingegneria Biomedica at the University of Bologna: Marilisa Cortesi. During the collaboration I contributed to a Synthetic Biology project already started in the Klavins Laboratory. In particular, I modeled and subsequently simulated a synthetic genetic circuit that was ideated for the implementation of a multicelled behavior in a growing bacterial microcolony. In the first chapter the foundations of molecular biology are introduced: structure of the nucleic acids, transcription, translation and methods to regulate gene expression. An introduction to Synthetic Biology completes the section. In the second chapter is described the synthetic genetic circuit that was conceived to make spontaneously emerge, from an isogenic microcolony of bacteria, two different groups of cells, termed leaders and followers. The circuit exploits the intrinsic stochasticity of gene expression and intercellular communication via small molecules to break the symmetry in the phenotype of the microcolony. The four modules of the circuit (coin flipper, sender, receiver and follower) and their interactions are then illustrated. In the third chapter is derived the mathematical representation of the various components of the circuit and the several simplifying assumptions are made explicit. Transcription and translation are modeled as a single step and gene expression is function of the intracellular concentration of the various transcription factors that act on the different promoters of the circuit. A list of the various parameters and a justification for their value closes the chapter. In the fourth chapter are described the main characteristics of the gro simulation environment, developed by the Self Organizing Systems Laboratory of the University of Washington. Then, a sensitivity analysis performed to pinpoint the desirable characteristics of the various genetic components is detailed. The sensitivity analysis makes use of a cost function that is based on the fraction of cells in each one of the different possible states at the end of the simulation and the wanted outcome. Thanks to a particular kind of scatter plot, the parameters are ranked. Starting from an initial condition in which all the parameters assume their nominal value, the ranking suggest which parameter to tune in order to reach the goal. Obtaining a microcolony in which almost all the cells are in the follower state and only a few in the leader state seems to be the most difficult task. A small number of leader cells struggle to produce enough signal to turn the rest of the microcolony in the follower state. It is possible to obtain a microcolony in which the majority of cells are followers by increasing as much as possible the production of signal. Reaching the goal of a microcolony that is split in half between leaders and followers is comparatively easy. The best strategy seems to be increasing slightly the production of the enzyme. To end up with a majority of leaders, instead, it is advisable to increase the basal expression of the coin flipper module. At the end of the chapter, a possible future application of the leader election circuit, the spontaneous formation of spatial patterns in a microcolony, is modeled with the finite state machine formalism. The gro simulations provide insights into the genetic components that are needed to implement the behavior. In particular, since both the examples of pattern formation rely on a local version of Leader Election, a short-range communication system is essential. Moreover, new synthetic components that allow to reliably downregulate the growth rate in specific cells without side effects need to be developed. In the appendix are listed the gro code utilized to simulate the model of the circuit, a script in the Python programming language that was used to split the simulations on a Linux cluster and the Matlab code developed to analyze the data.

Polymer properties measured by micromechanical cantilever technique

Surface stress changes induced by specific adsorption of molecules were investigated using a micromechanical cantilever sensor (MCS) device. 16 MCS are grouped within four separate wells. Each well can be addressed independently by different liquid enabling functionalization of MCS separately by flowing different solutions through each well and performing sensing and reference experiments simultaneously. In addition, each well contains a fixed reference mirror, which allows measuring the absolute bending of MCS. The effect of the flow rate on the MCS bending change was found to be dependent on the absolute bending value of MCS. In addition, the signal from the reference mirror can be used to follow refractive index changes upon mixing different solutions. Finite element simulation of solution exchange in wells was compared with experiment results. Both revealed that one solution can be exchanged by another one after a total volume of 200 µl has flown through. Using MCS, the adsorption of thiolated deoxyribonucleic acid (DNA) molecules and 6-mercapto-1-hexanol (MCH) on gold surfaces, and the DNA hybridization were performed. The nanomechanical response is in agreement with data reported by Fritz et al.1 Thus, the multiwell device is readily applicable for sensing of multiple chemical and biological recognition events in a single step. In this context controlled release and uptake of drugs are currently widely discussed. As a model system, we have used polystyrene (PS) spheres with diameters in the order of µm. The swelling behavior of individual PS spheres in toluene vapor was studied via mass loading by means of micromechanical cantilever sensors. For 4–8% cross-linked PS a mass increase of 180% in saturated toluene vapor was measured. In addition, the diameter change in saturated toluene vapor was measured and the corresponding volume increase of 200% was calculated. The mass of the swollen PS sphere decreases with increasing exposure time to ultraviolet (UV) light. The swelling response is significantly different between the first and the second exposure to toluene vapor. This is attributed to the formation of a cross-linked shell at the surface of the PS spheres. Shape persistent parts were observed for locally UV irradiated PS spheres. These PS spheres were found to be fluorescent and cracks occur after exposure in toluene liquid. The diffusion time of dye molecules in PS spheres increases with increasing chemical cross-linking density. This concept of locally dissolving non cross-linked PS from the sphere was applied to fabricate donut structures on surfaces. Arrays of PS spheres were fabricated using spin coating. The donut structure was produced simply after liquid solvent rinsing. The complete cross-linking of PS spheres was found after long exposure time to UV. We found that stabilizers play a major role in the formation of the donut nanostructures.

Catalytic processes for the transformation of ethanol into acetonitrile

This thesis deals with the transformation of ethanol into acetonitrile. Two approaches are investigated: (a) the ammoxidation of ethanol to acetonitrile and (b) the amination of ethanol to acetonitrile. The reaction of ethanol ammoxidation to acetonitrile has been studied using several catalytic systems, such as vanadyl pyrophosphate, supported vanadium oxide, multimetal molibdates and antimonates. The main conclusions are: (I) The surface acidity must be very low, because acidity catalyzes several undesired reactions, such as the formation of ethylene, and of heavy compounds as well. (II) Supported vanadium oxide is the catalyst showing the best catalytic behaviour, but the role of the support is of crucial importance. (III) Both metal molybdates and antimonates show interesting catalytic behaviour, but are poorly active, and probably require harder conditions than those used with the V oxide-based catalysts. (IV) One key point in the reaction network is the rate of reaction between acetaldehyde (the first intermediate) and ammonia, compared to the parallel rates of acetaldehyde transformation into by-products (CO, CO2, HCN, heavy compounds). Concerning the non-oxidative process, two possible strategies are investigated: (a) the ethanol ammonolysis to ethylamine coupled with ethylamine dehydrogenation, and (b) the direct non-reductive amination of ethanol to acetonitrile. Despite the good results obtained in each single step, the former reaction does not lead to good results in terms of yield to acetonitrile. The direct amination can be catalyzed with good acetonitrile yield over catalyst based on supported metal oxides. Strategies aimed at limiting catalyst deactivation have also been investigated.

Self assembled materials for solar cell application

In der vorliegenden Arbeit wurden Materialien und Aufbauten für Hybrid Solarzellen entwickelt und erforscht. rnDer Vergleich zweier bekannter Lochleitermaterialien für Solarzellen in einfachen Blend-Systemen brachte sowohl Einsicht zur unterschiedlichen Eignung der Materialien für optoelektronische Bauelemente als auch neue Erkenntnisse in Bereichen der Langzeitstabilität und Luftempfindlichkeit beider Materialien.rnWeiterhin wurde eine Methode entwickelt, um Hybrid Solarzelle auf möglichst unkomplizierte Weise aus kostengünstigen Materialien darzustellen. Die „Eintopf“-Synthese ermöglicht die unkomplizierte Darstellung eines funktionalen Hybridmaterials für die optoelektronische Anwendung. Mithilfe eines neu entwickelten amphiphilen Blockcopolymers, das als funktionelles Templat eingesetzt wurde, konnten mit einem TiO2-Precursor in einem Sol-Gel Ansatz verschiedene selbstorganisierte Morphologien des Hybridmaterials erhalten werden. Verschiedene Morphologien wurden auf ihre Eignung in Hybrid Solarzellen untersucht. Ob und warum die Morphologie des Hybridsystems die Effizienz der Solarzelle beeinflusst, konnte verdeutlicht werden. Mit der Weiterentwicklung der „Eintopf“-Synthese, durch den Austausch des TiO2-Precursors, konnte die Solarzelleneffizienz von 0.15 auf 0.4 % gesteigert werden. Weiterhin konnte die Übertragbarkeit des Systems durch den erfolgreichen Austausch des Halbleiters TiO¬2 mit ZnO bewiesen werden.rn

Misregulation of the tumour suppressor gene CYLD drives hyperactivation of T cells leading to intestinal pathology

The tumour suppressor gene cyld is mutated in familial cylindromatosis, an autosomal-dominant condition that predisposes to multiple skin tumours. The deubiquitinase CYLD acts as a negative regulator of NF-κB signaling. To analyse the function of CYLD in vivo we used the CYLDex7/8 mice, which are characterized by loss of the full-length transcript and overexpression of a short splice variant of CYLD (sCYLD). In CYLDex7/8 mice the overexpression of sCYLD results in splenomegaly and lymphadenopathy. Additionally, the B cell population in spleen and lymph nodes is increased at the expense of T cells. Analysis of CYLDex7/8 T cells showed a significant reduction of CD4 single positive (SP) and CD8 SP T cells in the thymus and in the periphery. By investigating the impact of sCYLD in TCR signaling in thymocytes, we could demonstrate that sCYLD partially inhibited the activation of Zap70 and thereby negatively regulated TCR signaling. In vitro as well as in vivo we could show that CD4+ T cells displayed a hyperactive phenotype, proliferated to a better extent than WT cells and expressed high amounts of inflammatory cytokines such as IL-6 and IL-17A. Western Blots of steady state thymocytes and peripheral CD4+ T cells were performed, showing that the noncanonical pathway was highly upregulated visualized by the expression levels of RelB and p100 leading to a hyperactive phenotype of CD4+ T cells. In order to investigate the contribution of sCYLD in positive and negative selection in the thymus in vivo, the HY-TCR transgene (HYtg) was crossed to CYLDex7/8 mice. The analysis of CYLDex7/8 HYtg males revealed an increase in CD4+CD8+ DP as well as in CD8+ SP thymocytes, suggesting a less pronounced negative selection in CYLD mutant mice compared to HYtg control mice. Interestingly, the impaired negative selection in the thymus was accompanied by a strong colitis phenotype at early ages (4 weeks). Since medullary TECs (mTECs) play an important role in the late stage of T cell development by negatively selecting autoreactive thymocytes, the levels of mTECs in the medullary compartment was investigated. Of note, low numbers of mTECs were observed, combined with decreased expression levels of the mTEC markers UEA-1, keratin-5, claudin-3 and claudin-4. The reduction of mTECs in the medullary compartment could explain the inflammatory phenotype of CD4+ T cells in CYLDex7/8 mice leading to the severe intestinal pathology observed in these mice. Taken together, these results show an important role of sCYLD in T cell development and function as well as in NF-кB signaling of T cells.

Next-state comfort in learning a vertical stick transportation sequence

Over the last decade, the end-state comfort effect (e.g., Rosenbaum et al., 2006) has received a considerable amount of attention. However, some of the underlying mechanisms are still to be investigated, amongst others, how sequential planning affects end-state comfort and how this effect develops over learning. In a two-step sequencing task, e.g., postural comfort can be planned on the intermediate position (next state) or on the actual end position (final state). It might be hypothesized that, in initial acquisition, next state’s comfort is crucial for action planning but that, in the course of learning, final state’s comfort is taken more and more into account. To test this hypothesis, a variant of Rosenbaum’s vertical stick transportation task was used. Participants (N = 16, right-handed) received extensive practice on a two-step transportation task (10,000 trials over 12 sessions). From the initial position on the middle stair of a staircase in front of the participant, the stick had to be transported either 20 cm upwards and then 40 cm downwards or 20 cm downwards and then 40 cm upwards (N = 8 per subgroup). Participants were supposed to produce fluid movements without changing grasp. In the pre- and posttest, participants were tested on both two-step sequencing tasks as well as on 20 cm single-step upwards and downwards movements (10 trials per condition). For the test trials, grasp height was calculated kinematographically. In the pretest, large end/next/final-state comfort effects for single-step transportation tasks and large next-state comfort effects for sequenced tasks were found. However, no change in grasp height from pre- to posttest could be revealed. Results show that, in vertical stick transportation sequences, the final state is not taken into account when planning grasp height. Instead, action planning seems to be solely based on aspects of the next action goal that is to be reached.

Decreasing gut wall glucose as an early marker of impaired intestinal perfusion

OBJECTIVE: The aim of this study was to assess the microcirculatory and metabolic consequences of reduced mesenteric blood flow. DESIGN: Prospective, controlled animal study. SETTING: The surgical research unit of a university hospital. SUBJECTS: A total of 13 anesthetized and mechanically ventilated pigs. INTERVENTIONS: Pigs were subjected to stepwise mesenteric blood flow reduction (15% in each step, n = 8) or served as controls (n = 5). Superior mesenteric arterial blood flow was measured with ultrasonic transit time flowmetry, and mucosal and muscularis microcirculatory perfusion in the small bowel were each measured with three laser Doppler flow probes. Small-bowel intramucosal Pco2 was measured by tonometry, and glucose, lactate (L), and pyruvate (P) were measured by microdialysis. MEASUREMENTS AND MAIN RESULTS: In control animals, superior mesenteric arterial blood flow, mucosal microcirculatory blood flow, intramucosal Pco2, and the lactate/pyruvate ratio remained unchanged. In both groups, mucosal blood flow was better preserved than muscularis blood flow. During stepwise mesenteric blood flow reduction, heterogeneous microcirculatory blood flow remained a prominent feature (coefficient of variation, approximately 45%). A 30% flow reduction from baseline was associated with a decrease in microdialysis glucose concentration from 2.37 (2.10-2.70) mmol/L to 0.57 (0.22-1.60) mmol/L (p < .05). After 75% flow reduction, the microdialysis lactate/pyruvate ratio increased from 8.6 (8.0-14.1) to 27.6 (15.5-37.4, p < .05), and arterial-intramucosal Pco2 gradients increased from 1.3 (0.4-3.5) kPa to 10.8 (8.0-16.0) kPa (p < .05). CONCLUSIONS: Blood flow redistribution and heterogeneous microcirculatory perfusion can explain apparently maintained regional oxidative metabolism during mesenteric hypoperfusion, despite local signs of anaerobic metabolism. Early decreasing glucose concentrations suggest that substrate supply may become crucial before oxygen consumption decreases.

Production of liquid core-polymer shell microcapsules

Polylactide (PLA) is a biodegradable polymer that has been used in particle form for drug release, due to its biocompatibility, tailorable degradation kinetics, and desirable mechanical properties. Active pharmaceutical ingredients (APIs) may be either dissolved or encapsulated within these biomaterials to create micro- or nanoparticles. Delivery of an AIP within fine particles may overcome solubility or stability issues that can result in early elimination or degradation of the AIP in a hostile biological environment. Furthermore, it is a promising method for controlling the rate of drug delivery and dosage. The goal of this project is to develop a simple and cost-effective device that allows us to produce monodisperse micro- and nanocapsules with controllable size and adjustable sheath thickness on demand. To achieve this goal, we have studied the dual-capillary electrospray and pulsed electrospray. Dual-capillary electrospray has received considerable attention in recent years due to its ability to create core-shell structures in a single-step. However, it also increases the difficulty of controlling the inner and outer particle morphology, since two simultaneous flows are required. Conventional electrospraying has been mainly conducted using direct-current (DC) voltage with little control over anything but the electrical potential. In contrast, control over the input voltage waveform (i.e. pulsing) in electrospraying offers greater control over the process variables. Poly(L-lactic acid) (PLLA) microspheres and microcapsules were successfully fabricated via pulsed-DC electrospray and dual-capillary electrospray, respectively. Core shell combinations produced include: Water/PLLA, PLLA/polyethylene glycol (PEG), and oleic Acid/PLLA. In this study, we designed a novel high-voltage pulse forming network and a set of new designs for coaxial electrospray nozzles. We also investigated the effect of the pulsed voltage characteristics (e.g. pulse frequency, pulse amplitude and pulse width) on the particle’s size and uniformity. We found that pulse frequency, pulse amplitude, pulse width, and the combinations of these factors had a statistically significant effect on the particle’s size. In addition, factors such as polymer concentration, solvent type, feed flow rate, collection method, temperature, and humidity can significantly affect the size and shape of the particles formed.

Reaction Control in Quiescent Systems of Free-Radical Retrograde-Precipitation Polymerization

Free-radical retrograde-precipitation polymerization, FRRPP in short, is a novel polymerization process discovered by Dr. Gerard Caneba in the late 1980s. The current study is aimed at gaining a better understanding of the reaction mechanism of the FRRPP and its thermodynamically-driven features that are predominant in controlling the chain reaction. A previously developed mathematical model to represent free radical polymerization kinetics was used to simulate a classic bulk polymerization system from the literature. Unlike other existing models, such a sparse-matrix-based representation allows one to explicitly accommodate the chain length dependent kinetic parameters. Extrapolating from the past results, mixing was experimentally shown to be exerting a significant influence on reaction control in FRRPP systems. Mixing alone drives the otherwise severely diffusion-controlled reaction propagation in phase-separated polymer domains. Therefore, in a quiescent system, in the absence of mixing, it is possible to retard the growth of phase-separated domains, thus producing isolated polymer nanoparticles (globules). Such a diffusion-controlled, self-limiting phenomenon of chain growth was also observed using time-resolved small angle x-ray scattering studies of reaction kinetics in quiescent systems of FRRPP. Combining the concept of self-limiting chain growth in quiescent FRRPP systems with spatioselective reaction initiation of lithography, microgel structures were synthesized in a single step, without the use of molds or additives. Hard x-rays from the bending magnet radiation of a synchrotron were used as an initiation source, instead of the more statistally-oriented chemical initiators. Such a spatially-defined reaction was shown to be self-limiting to the irradiated regions following a polymerization-induced self-assembly phenomenon. The pattern transfer aspects of this technique were, therefore, studied in the FRRP polymerization of N-isopropylacrylamide (NIPAm) and methacrylic acid (MAA), a thermoreversible and ionic hydrogel, respectively. Reaction temperature increases the contrast between the exposed and unexposed zones of the formed microgels, while the irradiation dose is directly proportional to the extent of phase separation. The response of Poly (NIPAm) microgels prepared from the technique described in this study was also characterized by small angle neutron scattering.

Immediate shear bond strengths of a composite, a compomer and a glass ionomer to a ceramic substrate.

PURPOSE To determine the best-performing combination of three core buildup materials and three bonding materials based on their bond strength to ceramic blocks in vitro. MATERIALS AND METHODS The materials used for core buildup were a composite (Tetric EvoCeram), a compomer (Compoglass F), and a glass-ionomer cement (Ketac Fil Plus), and for bonding, a three-step etch-and-rinse adhesive (Syntac), a two-step etch-and-rinse adhesive (ExciTE), and a single-step system (RelyX Unicem). Bond strength to ceramic blocks was determined by shear bond strength testing. Fracture behavior was evaluated by scanning electron microscopy. RESULTS The highest adhesive values between buildup and ceramic were obtained using the materials Compoglass F and Syntac, followed by Compoglass F and ExciTE. Among the two other core buildups, Tetric EvoCeram performed better than Ketac Fil Plus, which was independent of the bonding materials. Adhesive fractures were characteristically observed with Syntac and ExciTE, and cohesive fractures were characteristically observed with RelyX Unicem. CONCLUSION These data show that compomers bonded with a multistep adhesive system achieved statistically significantly higher shear bond strength than composites and glass-ionomer cements. Within the limitations inherent to this in vitro study, the use of compomers for core buildup can be recommended.

Probabilistic approach to cloud and snow detection on Advanced Very High Resolution Radiometer (AVHRR) imagery

Derivation of probability estimates complementary to geophysical data sets has gained special attention over the last years. Information about a confidence level of provided physical quantities is required to construct an error budget of higher-level products and to correctly interpret final results of a particular analysis. Regarding the generation of products based on satellite data a common input consists of a cloud mask which allows discrimination between surface and cloud signals. Further the surface information is divided between snow and snow-free components. At any step of this discrimination process a misclassification in a cloud/snow mask propagates to higher-level products and may alter their usability. Within this scope a novel probabilistic cloud mask (PCM) algorithm suited for the 1 km × 1 km Advanced Very High Resolution Radiometer (AVHRR) data is proposed which provides three types of probability estimates between: cloudy/clear-sky, cloudy/snow and clear-sky/snow conditions. As opposed to the majority of available techniques which are usually based on the decision-tree approach in the PCM algorithm all spectral, angular and ancillary information is used in a single step to retrieve probability estimates from the precomputed look-up tables (LUTs). Moreover, the issue of derivation of a single threshold value for a spectral test was overcome by the concept of multidimensional information space which is divided into small bins by an extensive set of intervals. The discrimination between snow and ice clouds and detection of broken, thin clouds was enhanced by means of the invariant coordinate system (ICS) transformation. The study area covers a wide range of environmental conditions spanning from Iceland through central Europe to northern parts of Africa which exhibit diverse difficulties for cloud/snow masking algorithms. The retrieved PCM cloud classification was compared to the Polar Platform System (PPS) version 2012 and Moderate Resolution Imaging Spectroradiometer (MODIS) collection 6 cloud masks, SYNOP (surface synoptic observations) weather reports, Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) vertical feature mask version 3 and to MODIS collection 5 snow mask. The outcomes of conducted analyses proved fine detection skills of the PCM method with results comparable to or better than the reference PPS algorithm.

Genetic Resistance Determinants, In Vitro Time-Kill Curve Analysis and Pharmacodynamic Functions for the Novel Topoisomerase II Inhibitor ETX0914 (AZD0914) in Neisseria gonorrhoeae.

Resistance in Neisseria gonorrhoeae to all available therapeutic antimicrobials has emerged and new efficacious drugs for treatment of gonorrhea are essential. The topoisomerase II inhibitor ETX0914 (also known as AZD0914) is a new spiropyrimidinetrione antimicrobial that has different mechanisms of action from all previous and current gonorrhea treatment options. In this study, the N. gonorrhoeae resistance determinants for ETX0914 were further described and the effects of ETX0914 on the growth of N. gonorrhoeae (ETX0914 wild type, single step selected resistant mutants, and efflux pump mutants) were examined in a novel in vitro time-kill curve analysis to estimate pharmacodynamic parameters of the new antimicrobial. For comparison, ciprofloxacin, azithromycin, ceftriaxone, and tetracycline were also examined (separately and in combination with ETX0914). ETX0914 was rapidly bactericidal for all wild type strains and had similar pharmacodynamic properties to ciprofloxacin. All selected resistant mutants contained mutations in amino acid codons D429 or K450 of GyrB and inactivation of the MtrCDE efflux pump fully restored the susceptibility to ETX0914. ETX0914 alone and in combination with azithromycin and ceftriaxone was highly effective against N. gonorrhoeae and synergistic interaction with ciprofloxacin, particularly for ETX0914-resistant mutants, was found. ETX0914, monotherapy or in combination with azithromycin (to cover additional sexually transmitted infections), should be considered for phase III clinical trials and future gonorrhea treatment.

Systematic literature review of digital three-dimensional superimposition techniques to create virtual dental patients

PURPOSE Digital developments have led to the opportunity to compose simulated patient models based on three-dimensional (3D) skeletal, facial, and dental imaging. The aim of this systematic review is to provide an update on the current knowledge, to report on the technical progress in the field of 3D virtual patient science, and to identify further research needs to accomplish clinical translation. MATERIALS AND METHODS Searches were performed electronically (MEDLINE and OVID) and manually up to March 2014 for studies of 3D fusion imaging to create a virtual dental patient. Inclusion criteria were limited to human studies reporting on the technical protocol for superimposition of at least two different 3D data sets and medical field of interest. RESULTS Of the 403 titles originally retrieved, 51 abstracts and, subsequently, 21 full texts were selected for review. Of the 21 full texts, 18 studies were included in the systematic review. Most of the investigations were designed as feasibility studies. Three different types of 3D data were identified for simulation: facial skeleton, extraoral soft tissue, and dentition. A total of 112 patients were investigated in the development of 3D virtual models. CONCLUSION Superimposition of data on the facial skeleton, soft tissue, and/or dentition is a feasible technique to create a virtual patient under static conditions. Three-dimensional image fusion is of interest and importance in all fields of dental medicine. Future research should focus on the real-time replication of a human head, including dynamic movements, capturing data in a single step.