Aortic injuries following stents in bariatric surgery: our experience

Background: Due to the large number of laparoscopic sleeve gastrectomy (LSG) performed over the last decade, the management of the leak following LSG has been increasingly reported. The role of covered Self Expandable Metal Stents (cSEMS) for the treatment of the leak is still controversial because of the poor tolerance and high risk of complications. Objectives: The aim of the present study was to analyze the foregut wall perforation and aorta injuries, a very rare but potentially fatal complication, related to the treatment of the leak following LSG using cSEMS. Setting: Private hospital, France. Methods: An audit was conducted in 2 French tertiary bariatric endoscopic centers focusing on aortic injuries after cSEMS use for leak. We examined and classified the initial procedure, leak characteristics, primary endoscopic treatment, and outcome of endoscopic complication for each eligible case. Results: A total of 5 patients were identified with foregut wall perforation and aorta injuries. All stents were deployed for staple line leak following LSG. The recorded mortality in case of esophageal-aortic injuries related to cSEMS use was 80%. Conclusion: cSEMS are potentially effective tools for the management of foregut leaks in bariatric surgery. The biggest challenges with this approach are stent migration and poor quality of life. Caution is required due to the risk of fatal complications such as foregut wall perforation and aortic injury

Parametric FEM simulation of composite barrier FTJs under external bias at room temperature

A study on a parametrized model of a composite barrier FTJ (three-interface system, with a non-polar dielectric layer) under an external bias voltage and at room temperature, using FEM-based simulations, was performed. The approach involves the Thomas-Fermi model assuming incomplete screening of polarization charges for building the energy barrier profile, and numerically simulates the electron transport through the barrier by bias-voltage-dependent tunneling, using Tsu-Esaki formulation. That naturally include the temperature dependent contributions to the total current density. The TER coefficient and current densities are computed considering variation of a large set of parameters that describe the composite barrier FTJ system in realistic physical range of values with respect to a reference (prototypical) system. In this study, the parametric simulations were performed starting from selected data reported on the SRO/STO/BTO/SRO heterostructure. The most important results of our work can be stated as follows: i) The FEM simulations prove to be reliable approach when we are interested in the prediction of FTJ characteristics at temperatures close to 300 K, and ii) We show that several configurations with large TER values may be predicted, but at the expense of very low current densities in the ON state. We suggest that the results may be useful for assessing the FTJ performances at ambient temperature, as well as to design preoptimized FTJs by using different combinations of materials to comply with a set of properties of a specific model

Computationally designed libraries of fluorescent proteins evaluated by preservation and diversity of function

To determine which of seven library design algorithms best introduces new protein function without destroying it altogether, seven combinatorial libraries of green fluorescent protein variants were designed and synthesized. Each was evaluated by distributions of emission intensity and color compiled from measurements made in vivo. Additional comparisons were made with a library constructed by error-prone PCR. Among the designed libraries, fluorescent function was preserved for the greatest fraction of samples in a library designed by using a structure-based computational method developed and described here. A trend was observed toward greater diversity of color in designed libraries that better preserved fluorescence. Contrary to trends observed among libraries constructed by error-prone PCR, preservation of function was observed to increase with a library's average mutation level among the four libraries designed with structure-based computational methods

Surface Fatigue Behaviour of a WC/aC:H Thin-Film and the Tribochemical Impact of Zinc Dialkyldithiophosphate

In wind turbine gearboxes, (near-)surface initiated fatigue is attributed to be the primary failure mechanism. In this work, the surface fatigue of a hydrogenated tungsten carbide/amorphous carbon (WC/aC:H) thin-film was tested under severe cyclic tribo-contact using PolyAlphaOlefin (PAO) and PAO + Zinc DialkylDithioPhosphate (ZDDP) lubricants. The film was characterised in terms of its structure and chemistry using X-ray diffraction, analytical Transmission Electron Microscopy (TEM) including Electron Energy Loss Spectroscopy (EELS), as well as X-ray Photoelectron Spectroscopy (XPS). The multilayer carbon thin-film exhibited promising surface fatigue performance showing a slight change in the hybridization state of the aC:H matrix. Dehydrogenation of the thin-film and subsequent transformation of cleaved C-H bonds to non planar sp2 carbon rings were inferred from EELS and XPS results. Whilst tribo-induced changes to the aC:H matrix were not influenced by a nanometer-thick ZDDP reaction-film, the rate of oxidation of WC and its oxidation state were affected. Whilst accelerating surface fatigue on a steel surface, the ZDDP-tribofilm protected the WC/aC:H film from surface fatigue. In contrast to the formation of polyphosphates from ZDDP molecules on steel surfaces, it appeared that on the WC/aC:H thin film surface ZDDP molecules decompose to ZnO suppressing the oxidative degradation of WC

String order in spin liquid phases of spin ladders

Two-leg spin ladders have a rich phase diagram if rung, diagonal and plaquette couplings are allowed for. Among the possible phases there are two Haldane-type spin liquid phases without local order parameter, which differ, however, in the topology of the short range valence bonds. We show that these phases can be distinguished numerically by two different string order parameters. We also point out that long range string- and dimer orders can coexist

Optimizing end-labeled free-solution electrophoresis by increasing the hydrodynamic friction of the drag-tag

We study the electrophoretic separation of polyelectrolytes of varying lengths by means of end-labeled free-solution electrophoresis (ELFSE). A coarse-grained molecular dynamics simulation model, using full electrostatic interactions and a mesoscopic Lattice Boltzmann fluid to account for hydrodynamic interactions, is used to characterize the drag coefficients of different label types: linear and branched polymeric labels, as well as transiently bound micelles. It is specifically shown that the label's drag coefficient is determined by its hydrodynamic size, and that the drag per label monomer is largest for linear labels. However, the addition of side chains to a linear label offers the possibility to increase the hydrodynamic size, and therefore the label efficiency, without having to increase the linear length of the label, thereby simplifying synthesis. The third class of labels investigated, transiently bound micelles, seems very promising for the usage in ELFSE, as they provide a significant higher hydrodynamic drag than the other label types. The results are compared to theoretical predictions, and we investigate how the efficiency of the ELFSE method can be improved by using smartly designed drag-tags.Comment: 32 pages, 11 figures, submitted to Macromolecule

The experience of pediatric surgery clinic in the treatment of hemangiomas and vascular malformations

Universitatea de Medicină şi Farmacie “Grigore T. Popa”, Clinica de Chirurgie şi Ortopedie Pediatrică a Spitalului Clinic de Urgenţă pentru Copii "Sfânta Maria", Iaşi, Al XIII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” și al III-lea Congres al Societății de Endoscopie, Chirurgie miniminvazivă și Ultrasonografie ”V.M.Guțu” din Republica MoldovaIntroducere: Afecţiunile congenitale vasculare includ tumorile vasculare (hemangioamele infantile, hemangioendoteliomul caposiform, hemangioame non-involutive, hemangioame rapid-involutive) şi malformaţii vasculare (capilare, venoase, limfatice, arteriovenoase şi mixte). Hemangioamele sunt cele mai frecvente tumori benigne vasculare în populaţia pediatrică iar localizarea lor poate fi unică – extremitate cefalică (60%), trunchi (25%) sau multiplă, impunând extinderea investigaţiilor pentru interesarea viscerală (hemangioame hepatice, intestinale, splenice, intracraniene, renale). Malformaţiile capilare apar ca leziuni singulare sau în asociere în cadrul altor afecţiuni – sindrom Struge-Weber, sindrom Klippel-Trenaunay. Cunoscute în trecut ca limfangioame, malformaţiile limfatice sunt clasificate acum ca fiind microcistice, macrocistice (localizate mai frecvent la nivelul capului şi gâtului) sau mixte. Material și metode: Lucrarea prezintă cazuri de hemangioame din colecţia clinicii, aspectul lor clinic şi evoluţia sub terapie cu un beta-blocant. Experienţa Clinicii de Chirurgie Pediatrică Iaşi privind utilizarea Propranololului datează din 2011 şi se datorează participării într+un studiu internaţional multicentric dublu-orb randomizat privind eficienţa şi siguranţa utilizării mai multor scheme de betablocant în tratamentul hemangioamelor infantile. Acest studiu a condus la aprobarea produsului Hemangiol de către Agenţia Europeană a Medicamentelor (EMA). Rezultate și concluzii: Hemangioamele au un prognostic bun, cu 98% rata de răspuns la administrarea de Propranolol.Introduction: The vascular congenital disorders include vascular tumor (hemangioma, kaposiform hemangioendothelioma, tufted hemangioma, non-involuting congenital hemangioma, rapidly-involuting congenital hemangioma) and vascular malformation (capillary, venous, lymphatic, arteriovenous and mixed malformations). Hemangiomas are the most common benign vascular tumors in the pediatric age and their localization may be unique – head (60%) and trunk (25%) or multiple, requiring extensive investigations for visceral involvement (hepatic, intestinal, splenic, intracranial, renal). Capillary malformations occur as isolated lesions or in association with other disorders – Struge-Weber syndrome, Klippel-Trenaunay syndrome. Lymphatic malformations, previously known as lymphangiomas are classified as microcystic, macrocystic (often present on the head and neck) or mixed. Material and methods: The paper presents cases of hemagiomas on the clinic’s collection, their clinical aspects and evolution under the pharmacotherapy with a beta-blocker. The experience of the Pediatric Surgery Clinic in Iasi regarding the use of Propranolol dates back to 2011 and is due to participation in a randomized, double-blind, multi-center international study on the safety and efficiency of betablockers in the treatment of infantile hemangiomas. The study led to the approval of Hemangiol by EMA (European Medicines Agency). Results and conclusions: Hemangiomas have a good prognosis with a 98% response to Propranolol administration

Paget's disease of the breast in a male with lymphomatoid papulosis: a case report

<p>Abstract</p> <p>Introduction</p> <p>Paget's disease is an eczematous skin change of the nipple that is usually associated with an underlying breast malignancy. Male breast cancer represents only 1-3% of all breast malignancies and Paget's disease remains very rare.</p> <p>Case presentation</p> <p>We present the case of a 67-year-old Caucasian man with lymphomatoid papulosis who was diagnosed with Paget's disease of the nipple and who was treated successfully with surgery alone. We discuss the presentation, investigations, management and pathogenesis of Paget's disease of the nipple.</p> <p>Conclusion</p> <p>The case highlights the need to be vigilant when new skin lesions arise in the context of an underlying chronic skin disorder.</p