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Background and study aims: Enteral stent placement has emerged as a safe and effective palliative treatment option for patients with malignant gastric outlet obstruction (GOO). In an attempt to further optimize this treatment new enteral stents have been designed. This study is the first to describe the results regarding technical success, clinical success, complication rate, and stent dysfunction of the Evolution duodenal stent (Cook Medical, Limerick, Ireland). Patients and methods: A total of 46 patients with symptomatic malignant GOO were included in this prospective multicenter cohort study. All patients who successfully received an Evolution duodenal stent were followed until death. Results: The technical and clinical success rates were 89% (95% confidence interval [CI] 77%-95%) and 72% (95 %CI 58%-83%), respectively. The GOO Scoring System score, the Global Health Score, and the EuroQol visual analog scale improved significantly (GOOSS and Global Health Score P<0.0001; EuroQol P=0.005) when scores before stenting were compared with scores after stent placement. Median survival was 87 days, and stent patency was observed in 67% for up to 395 days, accounting for death unrelated to the stent as a competing risk. Stent dysfunction occurred in 14 patients (30 %) (stent ingrowth n=9; stent migration n=2; extrinsic compression on the stent n=2; food impaction n=1). Conclusion: These first data on the new Evolution duodenal stent show that it is safe and effective for the palliative treatment of symptomatic malignant GOO. [ABSTRACT FROM AUTHOR]

Individual perovskite-like LaCoO3 obtained by the citrate method and LaCoO3 supported onto the mesoporous molecular sieve MSM-41 have been characterized by X-ray powder diffraction, EPMA, low-temperature nitrogen adsorption, H2 TPR, and EXAFS. The catalytic activity of the supported cobaltate in methanol oxidation is two orders of magnitude higher than the activity of the bulk cobaltate owing to nanosized LaCoO3 particles in the pores of the molecular sieve. [ABSTRACT FROM AUTHOR]

Methanol catalysis meets chemistry under confined conditions. Methanol is regarded as one of the most important future energy sources. ZnO/Cu composite materials are very effective in heterogeneous catalysis for methanol production due to the so-called strong metal–support interaction effect (SMSI). Therefore, materials of superior structural design potentially representing model systems for heterogeneous catalysis are highly desired. Ultimately, such materials could help to understand the interaction between copper and zinc oxide in more detail than currently possible. We report the preparation of nanocrystalline, size-selected ZnO inside the pore system of ordered mesoporous silica materials. A new, liquid precursor for ZnO is introduced. It is seen that the spatial confinement significantly influences the chemical properties of the precursor as well as determines a hierarchical architecture of the final ZnO/SiO2 nanocomposites. Finally, the ability of the materials to act as model systems in methanol preparation is investigated. The materials are characterized by a variety of techniques including electron microscopy, X-ray scattering, solid- state NMR, EPA, EXAFS, and Raman spectroscopy, and physisorption analysis. [ABSTRACT FROM AUTHOR]

The article focuses on the formation of linear tetramers of diarylalkynes by the Zr/Cr system. Oligomerization of alkynes catalyzed or mediated by transition metal complexes is of great interest since it can be an efficient way to construct new π -conjugated compounds, which attract much attention in the area of organic functional materials. Although dimerization and cyclic trimerization of alkynes are well-known, selective formation of higher linear oligomers of alkynes is rare. In this the authors report a novel Zr/Cr system for linear tetramer formation of diarylalkynes.

Upper gastrointestinal perforations, fistula, and anastomotic leaks are severe conditions with high mortality. Temporary endoscopic placement of fully covered self-expanding metal stent (fSEMS) has emerged as treatment option. Stent migration is a major drawback of currently used stents. Migration is often attributed to a relatively too small stent diameter as esophageal stents were initially intended for the treatment of strictures. This study aimed to investigate the safety and efficacy of a large-diameter fSEMS for treatment of these conditions. Data were retrospectively collected from patients who received this stent in the Netherlands between March 2011 and August 2013. Clinical success was defined as sufficient leak closure after stent removal as confirmed by endoscopy or X-ray with oral contrast without surgical intervention or placement of another type of stent. Adverse events were graded according a standardized grading system. Stent placement was performed in 34 patients for the following indications: perforation (n = 6), anastomotic leak (n = 26), and fistula (n = 2). Technical success rate was 97% (33/34). Clinical success rate was 44% (15/34) after one stent and 50% (17/34) after an additional stent. There were no severe adverse events and stent-related mortality. The overall adverse event rate was 50% (all graded 'moderate'). There were 14 (41%) stent migrations (complete n = 8, partial n = 6). Other adverse events were bleeding (n = 2) and aspiration pneumonia (n = 1). Reinterventions for failure of the large-diameter fSEMS were placement of another type of fSEMS (n = 4), surgical repair (n = 3), or esophagectomy (n = 1). Eleven patients (32%) died in-hospital because of persisting intrathoracic sepsis (n = 10) or preexistent bowel ischemia (n = 1). This study suggests that temporary placement of a large-diameter fSEMS for the treatment of upper gastrointestinal perforations, fistula, and anastomotic leaks is safe in terms of severe adverse events and stent-related mortality. The larger diameter does not seem to prevent stent migration., (© 2015 International Society for Diseases of the Esophagus.)