Treatment of Persistent Large Gastrocutaneous Fistulas After Bariatric Surgery. Preliminary Experience with Endoscopic Kehr's T-Tube Placement

Purpose Post-bariatric surgery gastrocutaneous fistula is a chronic leak with an incidence of 1.7 to 4.0% and no standardized management. A large gastrocutaneous fistula (LGCF) is not indicated for treatment with pigtail drains. We aimed to evaluate results of a novel treatment using endoscopic Kehr's T-tube placement.Methods Only patients with a postoperative LGCF duration of >10 days and a flow rate of > 50 cc by external drainage after revisional surgery for sepsis were included. Endoscopic placement of Kehr's T-tube was performed. Patients had been reoperated with wash and drainage for severe sepsis after initial bariatric surgery in which no fistula had been discovered. Patients not reoperated, or with a fistula requiring intraoperative Kehr's T-tube placement, or a pigtail drain were excluded. Primary outcomes were endoscopic characteristics and results (LGCF closure rate, Kehr T-tube retention time, etc.).Results The study group included 12 women, 2 men; body mass index 43.1 +/- 4.5 kg/m(2). Interventions were SG (7), RYGB (2), OAGB (4), and SADI-S (1). Endoscopic assessment was carried out after a mean of 33.2 +/- 44.3 days after the bariatric procedure. The mean fistula orifice diameter was 2.0 +/- 0.9 cm. Kehr's T-tube was positioned at a mean 51.5 +/- 54.8 days after the bariatric procedure. T-tube tolerance was excellent. Mean additional days: hospitalization, 34.4 +/- 27.0; T-tube retention, 86.4 +/- 73.1; fistula healing, 139.9 +/- 111.5,LGCF closure rate, 92.9%. Complications: 1 pulmonary embolism, 2 T-tube migrations,1 drain-path bleed, 1 skin abscess. No mortality.Conclusions Endoscopic Kehr's T-tube placement was successful in closing persistent post-bariatric surgery LGCF in 92.9% of patients

Gold as a Tool for Hedging Financial Risks

The article discusses gold as a protective asset, which claims to be a high-efficiency tool for hedging financial risks. In the introductory part the general characteristics of hedging as a method of full or partial risk elimination is given, and the main known types of risk hedging typical for a financial asset portfolio holder are considered. Further, dynamics of the world prices for gold is analyzed in a historical retrospective, whereby the conclusion is drawn on a tendency of this asset to grow during the periods of financial instability, and also if new financial assets appear. In the final part of the article the assessment of gold as a tool for hedging financial risks is given

CALIFA, the Calar Alto Legacy Integral Field Area survey: I. Survey presentation

We present here the Calar Alto Legacy Integral Field Area (CALIFA) survey, which has been designed to provide a first step in this direction.We summarize the survey goals and design, including sample selection and observational strategy.We also showcase the data taken during the first observing runs (June/July 2010) and outline the reduction pipeline, quality control schemes and general characteristics of the reduced data. This survey is obtaining spatially resolved spectroscopic information of a diameter selected sample of $\sim600$ galaxies in the Local Universe (0.005< z <0.03). CALIFA has been designed to allow the building of two-dimensional maps of the following quantities: (a) stellar populations: ages and metallicities; (b) ionized gas: distribution, excitation mechanism and chemical abundances; and (c) kinematic properties: both from stellar and ionized gas components. CALIFA uses the PPAK Integral Field Unit (IFU), with a hexagonal field-of-view of \sim1.3\sq\arcmin', with a 100% covering factor by adopting a three-pointing dithering scheme. The optical wavelength range is covered from 3700 to 7000 {\AA}, using two overlapping setups (V500 and V1200), with different resolutions: R\sim850 and R\sim1650, respectively. CALIFA is a legacy survey, intended for the community. The reduced data will be released, once the quality has been guaranteed. The analyzed data fulfill the expectations of the original observing proposal, on the basis of a set of quality checks and exploratory analysis. We conclude from this first look at the data that CALIFA will be an important resource for archaeological studies of galaxies in the Local Universe.Comment: 32 pages, 29 figures, Accepted for publishing in Astronomy and Astrophysic

The VANDELS ESO public spectroscopic survey: Observations and first data release

This paper describes the observations and the first data release (DR1) of the ESO public spectroscopic survey “VANDELS, a deep VIMOS survey of the CANDELS CDFS and UDS fields”. The main targets of VANDELS are star-forming galaxies at redshift 2.4 < z < 5.5, an epoch when the Universe had not yet reached 20% of its current age, and massive passive galaxies in the range 1 < z < 2.5. By adopting a strategy of ultra-long exposure times, ranging from a minimum of 20 h to a maximum of 80 h per source, VANDELS is specifically designed to be the deepest-ever spectroscopic survey of the high-redshift Universe. Exploiting the red sensitivity of the refurbished VIMOS spectrograph, the survey is obtaining ultra-deep optical spectroscopy covering the wavelength range 4800–10 000 Å with a sufficiently high signal-to-noise ratio to investigate the astrophysics of high-redshift galaxy evolution via detailed absorption line studies of well-defined samples of high-redshift galaxies. VANDELS-DR1 is the release of all medium-resolution spectroscopic data obtained during the first season of observations, on a 0.2 square degree area centered around the CANDELS-CDFS (Chandra deep-field south) and CANDELS-UDS (ultra-deep survey) areas. It includes data for all galaxies for which the total (or half of the total) scheduled integration time was completed. The DR1 contains 879 individual objects, approximately half in each of the two fields, that have a measured redshift, with the highest reliable redshifts reaching zspec ~ 6. In DR1 we include fully wavelength-calibrated and flux-calibrated 1D spectra, the associated error spectrum and sky spectrum, and the associated wavelength-calibrated 2D spectra. We also provide a catalog with the essential galaxy parameters, including spectroscopic redshifts and redshift quality flags measured by the collaboration. We present the survey layout and observations, the data reduction and redshift measurement procedure, and the general properties of the VANDELS-DR1 sample. In particular, we discuss the spectroscopic redshift distribution and the accuracy of the photometricredshifts for each individual target category, and we provide some examples of data products for the various target typesand the different quality flags. All VANDELS-DR1 data are publicly available and can be retrieved from the ESO archive. Two further data releases are foreseen in the next two years, and a final data release is currently scheduled for June 2020, which will include an improved rereduction of the entire spectroscopic data set

Functional hydrogels: ferrogel thin films

Die Kombination magnetischer Nanopartikel (NP) mit temperatursensitiven Polymeren führt zur Bildung neuer Komposit-Materialien mit interessanten Eigenschaften, die auf vielfältige Weise genutzt werden können. Mögliche Anwendungsgebiete liegen in der magnetischen Trennung, der selektiven Freisetzung von Medikamenten, dem Aufbau von Sensoren und Aktuatoren. Als Polymerkomponente können z.B. Hydrogele dienen. Die Geschwindigkeit der Quellgradänderung mittels externer Stimuli kann durch eine Reduzierung des Hydrogelvolumens erhöht werden, da das Quellen ein diffusionskontrollierter Prozess ist. rnIm Rahmen dieser Arbeit wurde ein durch ultraviolettes Licht vernetzbares Hydrogel aus N-isopropylacrylamid, Methacrylsäure und dem Vernetzer 4-Benzoylphenylmethacrylat hergestellt (PNIPAAm-Hydrogel) und mit magnetischen Nanopartikeln aus Magnetit (Fe3O4) kombiniert. Dabei wurde die Temperatur- und die pH-Abhängigkeit des Quellgrades im Hinblick auf die Verwendung als nanomechanische Cantilever Sensoren (NCS) untersucht. Desweiteren erfolgte eine Charakterisierung durch Oberflächenplasmonen- und optischer Wellenleitermoden-Resonanz Spektroskopie (SPR/OWS). Die daraus erhaltenen Werte für den pKa-Wert und die lower critical solution Temperatur (LCST) stimmten mit den bekannten Literaturwerten überein. Es konnte gezeigt werden, dass eine stärkere Vernetzung zu einer geringeren LCST führt. Die Ergebnisse mittels NCS wiesen zudem auf einen skin-effect während des Heizens von höher vernetzten Polymeren hin.rnDie Magnetit Nanopartikel wurden ausgehend von Eisen(II) acetylacetonat über eine Hochtemperaturreaktion synthetisiert. Durch Variation der Reaktionstemperatur konnte die Größe der hergestellten Nanopartikel zwischen 3.5 und 20 nm mit einer Größenverteilung von 0.5-2.5 nm eingestellt werden. Durch geeignete Oberflächenfunktionalisierung konnten diese in Wasser stabilisiert werden. Dazu wurde nach zwei Strategien verfahren: Zum einen wurden die Nanopartikel mittels einer Silika-Schale funktionalisiert und zum anderen Zitronensäure als Tensid eingesetzt. Wasserstabilität ist vor allem für biologische Anwendungen wünschenswert. Die magnetischen Partikel wurden mit Hilfe von Transmissionselektronenmikroskopie (TEM), und superconductive quantum interference device (SQUID) charakterisiert. Dabei wurde eine Größenabhängigkeit der magnetischen Eigenschaften sowie superparamagnetisches Verhalten beobachtet. Außerdem wurde die Wärmeerzeugung der magnetischen Nanopartikel in einem AC Magnetfeld untersucht. rnDie Kombination beider Komponenten in Form eines Ferrogels wurde durch Mischen Benzophenon funktionalisierter magnetischer Nanopartikel mit Polymer erreicht. Durch Aufschleudern (Spin-Coaten) wurden dünne Filme erzeugt und diese im Hinblick auf ihr Verhalten in einem Magnetfeld untersucht. Dabei wurde eine geringes Plastikverhalten beobachtet. Die experimentellen Ergebnisse wurden anschließend mit theoretisch berechneten Erwartungswerten verglichen und mit den unterschiedlichen Werten für dreidimensionale Ferrogele in Zusammenhang gestellt. rnThe combination of magnetic nanoparticles (NPs) with thermoresponsive polymer systems leads to the formation of composite materials with a wide range of potential applications such as magnetic separation, drug release systems, sensors and actuators. The response time to external stimuli can be reduced by the reduction of the hydrogel matrix volume since swelling is a diffusion-controlled phenomenon.rnIn this work, a UV-crosslinkable polymer, consisting of N-isopropylacrylamide, methacrylic acid and the UV-crosslinker 4-benzoylphenyl methacrylate was used in conjunction with magnetite nanoparticles. The temperature and pH influence on the gel were studied by means of nanomechanical cantilever sensors (NCS) and surface plasmon resonance with optical waveguide mode spectroscopy (SPR/OWS). The obtained values of polymer pKa and lower critical solution temperature (LCST) were in agreement with literature values. It was found that higher crosslinked networks exhibit a lower LCST. NCS provided additional insight into polymer physics of the hydrogel showing stresses caused by skin-effect in the heating of higher crosslinked networks. rnFe3O4 nanoparticles were synthesized from iron(III) acetylacetonate using a high temperature reaction. By changing the reaction temperature a control on the NP size was achieved from 3.5 nm to 20 nm with a size distribution between 0.5 and 2.5. In addition, magnetite nanopartices were functionalized to allow stabilization in aqueous environment through two strategies: a silica shell or a citric acid surfactant; thus, opening the door for the nanoparticles to bioapplications. The magnetic nanoparticles were analyzed by transmission electron microscopy (TEM) and superconductive quantum interference device (SQUID). A size dependence of the magnetic properties was observed and a superparamagnetic character was confirmed. In addition, the heat loss of the nanoparticles exposed to an AC magnetic field was investigated. rnA ferrogel was formed through the mixing of magnetite nanoparticles, functionalized with benzophenone for the first time, and PNIPAAm polymer. The polymer was spincoated into a thin film, whose behavior in front of a magnetic field gradient was investigated. The results showed a small plastic response. The results were compared to theoretical calculations, which explained the different response in comparison with bulk ferrogels.r