Background
Various minimally invasive approaches have been described for infected necrotizing pancreatitis. This article describes a modified minimal‐access retroperitoneal pancreatic necrosectomy ...(MARPN) procedure assisted by gas insufflation.
Methods
This retrospective, observational study documented patients who had undergone a step‐up MARPN between 1 January 2010 and 31 December 2016. A minimum follow‐up of 1 year was required for inclusion. The step‐up approach involved percutaneous catheter drainage followed by the modified MARPN and necrosectomy. If more than one access site was needed it was categorized as complex MARPN.
Results
Of 212 patients with infected necrotizing pancreatitis, 164 (77·4 per cent) underwent a step‐up approach. The median number of percutaneous catheter drains and MARPN procedures was 3 (range 1–7) and 1 (1–6) respectively. Ninety patients (54·9 per cent) underwent complex MARPN. For residual necrosis after MARPN, three patients (1·8 per cent) underwent sinus tract gastroscopy, and 11 (6·7 per cent) had sinography combined with a tube change. However, operations in 13 patients (7·9 per cent) required conversion to open surgery. Postoperative complications developed in 103 patients (62·8 per cent). The mortality rate was 6·1 per cent (10 deaths).
Conclusion
A step‐up approach using a modified MARPN for infected necrotizing pancreatitis is a reasonable option.
Antecedentes
Los procedimientos mínimamente invasivos se han convertido en los más frecuentes para el tratamiento de necrosis pancreáticas infectadas. El objetivo de este estudio fue presentar un procedimiento de necrosectomía pancreática retroperitoneal de acceso mínimo (minimal‐access retroperitoneal pancreatic necrosectomy, MARPN) modificado y asistido mediante insuflación de gases, así como evaluar su seguridad y eficacia.
Métodos
Se realizó un análisis retrospectivo y observacional de los datos de un hospital desde el 1 de enero de 2010 hasta el 31 de diciembre de 2016. Se incluyeron en el análisis todos los pacientes en los que realizó un abordaje por etapas, que consistía en el drenaje percutáneo mediante la colocación de un catéter seguido de un procedimiento MARPN modificado, en los que se dispusiese de un seguimiento postoperatorio mínimo de 1 año. El MARPN en el lado derecho y la necrosectomía realizada a través de más de un acceso se clasificaron como MARPN complejo. Se evaluaron los resultados radiológicos y quirúrgicos.
Resultados
De 212 pacientes con necrosis pancreática infectada, en 164 (77,4%) se realizó un abordaje por etapas. La mediana del número de drenajes percutáneos y procedimientos MARPN fue 3 (rango, 1‐7) y 1 (rango, 1‐6), respectivamente. En 90 pacientes (54,9%) se realizó un MARPN complejo. Para la exéresis de necrosis residual después de un MARPN, en 3 pacientes (1,8%) se realizó mediante gastroscopia y en 11 pacientes (6,7%) con un recambio de drenaje bajo control radiológico. En 13 pacientes (7,9%) fue necesaria la reconversión a cirugía abierta. Hubo complicaciones postoperatorias en 103 pacientes (62,8%). La tasa de mortalidad fue del 6,1% (n = 10).
Conclusión
El abordaje por etapas con un MARPN modificado es seguro y efectivo en el tratamiento de la necrosis pancreática infectada.
Minimally invasive approaches have been used increasingly in the management of infected necrotizing pancreatitis. This study presents a modified minimal‐access retroperitoneal pancreatic necrosectomy procedure assisted by carbon dioxide insufflation, instead of saline. A clear field of view without necrotic debris floating in saline makes the technique safe and efficient.
High degree of success
VIDEO
Presented in part to the Joint Congress of the Sixth Biennial Congress of the Asian–Pacific Hepato‐Pancreato‐Biliary Association and the 29th Meeting of the Japanese Society of Hepato‐Biliary‐Pancreatic Surgery, Yokohama, Japan, June 2017
This paper reports an experimental investigation of the near wake of a finite-length square cylinder, with one end mounted on a flat plate and the other free. The cylinder aspect ratio or ...height-to-width ratio H/d ranges from 3 to 7. Measurements were carried out mainly in a closed-loop low-speed wind tunnel at a Reynolds number Red, based on d and the free-stream velocity of 9300 using hot-wire anemometry, laser Doppler anemometry and particle image velocimetry (PIV). The planar PIV measurements were performed in the three orthogonal planes of the three-dimensional cylinder wake, along with flow visualization conducted simultaneously in two orthogonal planes (Red = 221). Three types of vortices, i.e. the tip, base and spanwise vortices were observed and the near wake is characterized by the interactions of these vortices. Both flow visualization and two-point correlation point to an inherent connection between the three types of vortices. A model is proposed for the three-dimensional flow structure based on the present measurements, which is distinct from previously proposed models. The instantaneous flow structure around the cylinder is arch-type, regardless of H/d, consisting of two spanwise vortical ‘legs’, one on each side of the cylinder, and their connection or ‘bridge’ near the free end. Both tip and base vortices are the streamwise projections of the arch-type structure in the (y, z) plane, associated with the free-end downwash flow and upwash flow from the wall, respectively. Other issues such as the topological characteristics, spatial arrangement and interactions among the vortical structures are also addressed.
We report a study of the processes of e^{+}e^{-}→K^{+}D_{s}^{-}D^{*0} and K^{+}D_{s}^{*-}D^{0} based on e^{+}e^{-} annihilation samples collected with the BESIII detector operating at BEPCII at five ...center-of-mass energies ranging from 4.628 to 4.698 GeV with a total integrated luminosity of 3.7 fb^{-1}. An excess of events over the known contributions of the conventional charmed mesons is observed near the D_{s}^{-}D^{*0} and D_{s}^{*-}D^{0} mass thresholds in the K^{+} recoil-mass spectrum for events collected at sqrts=4.681 GeV. The structure matches a mass-dependent-width Breit-Wigner line shape, whose pole mass and width are determined as (3982.5_{-2.6}^{+1.8}±2.1) MeV/c^{2} and (12.8_{-4.4}^{+5.3}±3.0) MeV, respectively. The first uncertainties are statistical and the second are systematic. The significance of the resonance hypothesis is estimated to be 5.3 σ over the contributions only from the conventional charmed mesons. This is the first candidate for a charged hidden-charm tetraquark with strangeness, decaying into D_{s}^{-}D^{*0} and D_{s}^{*-}D^{0}. However, the properties of the excess need further exploration with more statistics.
Refractory high-entropy alloys hold the potential for high-temperature applications beyond the capability of the state-of-the-art Ni-based superalloys, and thus, it is important to study their solid ...solution formation characteristics and mechanical properties. In this study, designed by CALPHAD method, formation of as-cast arc-melted body-centered cubic MoNbTaTiV was experimentally verified using X-ray diffraction and scanning electron microscopy. The measured density and lattice parameter for MoNbTaTiV are 9.29g/cm3 and 3.224 Å, which obey the rule of mixtures (ROM). The alloy exhibits high hardness at 443 Hv, high yield strength at 1.4 GPa, and good compressive fracture strength at 2.45 GPa with a fracture strain of ∼30% at room temperature. The yield strength and hardness values of this alloy, and other single-phase refractory high-entropy alloys, are estimated using a simple model of solid solution strengthening. Reasonable agreement between modeling prediction and experiments is obtained. In addition, first-principles density functional theory calculations predict an enthalpy of formation of −0.865 kJ/mol for the MoNbTaTiV alloy, with calculated atomic volume and elastic properties (e.g., bulk and elastic moduli) obeying the ROM.
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•MoNbTaTiV exhibits the BCC structure, agreeing with CALPHAD calculations.•Predicted solid solution strengthening agrees well with experiments.•Hardness of BCC high entropy alloys is about three times the yield strength.•Calculated atomic volume and bulk and shear moduli obey the rule of mixtures.
The cross section for the process e^{+}e^{-}→π^{+}π^{-}J/ψ is measured precisely at center-of-mass energies from 3.77 to 4.60 GeV using 9 fb^{-1} of data collected with the BESIII detector operating ...at the BEPCII storage ring. Two resonant structures are observed in a fit to the cross section. The first resonance has a mass of (4222.0±3.1±1.4) MeV/c^{2} and a width of (44.1±4.3±2.0) MeV, while the second one has a mass of (4320.0±10.4±7.0) MeV/c^{2} and a width of (101.4_{-19.7}^{+25.3}±10.2) MeV, where the first errors are statistical and second ones are systematic. The first resonance agrees with the Y(4260) resonance reported by previous experiments. The precision of its resonant parameters is improved significantly. The second resonance is observed in e^{+}e^{-}→π^{+}π^{-}J/ψ for the first time. The statistical significance of this resonance is estimated to be larger than 7.6σ. The mass and width of the second resonance agree with the Y(4360) resonance reported by the BABAR and Belle experiments within errors. Finally, the Y(4008) resonance previously observed by the Belle experiment is not confirmed in the description of the BESIII data.
This study reports the design and development of ductile and strong refractory single-phase high-entropy alloys (HEAs) for high temperature applications, based on NbTaV with addition of Ti and W. ...Assisted by CALPHAD modeling, a single body-centered cubic solid solution phase was experimentally confirmed in the as-cast ingots using X-ray diffraction and scanning electron microscopy. The observed elemental segregation in each alloy qualitatively agrees with CALPHAD prediction. The Vickers microhardnesses (and yield strengths) of the alloys are about 3 (and 3.5–4.4) times that those estimated from the rule of mixture. While NbTaTiVW shows an impressive yield strength of 1420MPa with fracture strain of 20%, NbTaTiV exhibits exceptional compressive ductility at room temperature.
To identify the bacterial and archaeal composition in a mesophilic biogas digester treating pig manure and to compare the consistency of two 16S rDNA-based methods to investigate the microbial ...structure. Sixty-nine bacterial operational taxonomic units (OTU) and 25 archaeal OTU were identified by sequencing two 16S rDNA clone libraries. Most bacterial OTU were identified as phyla of Firmicutes (47·2% of total clones), Bacteroides (35·4%) and Spirochaetes (13·2%). Methanoculleus bourgensis (29·0%), Methanosarcina barkeri (27·4%) and Methanospirillum hungatei (10·8%) were the dominant methanogens. Only 9% of bacterial and 20% of archaeal OTU matched cultured isolates at a similarity index of greater-than-or-equal97%. About 78% of the dominant bacterial (with abundance >3%) and 83% of archaeal OTU were recovered from the denaturing gradient gel electrophoresis (DGGE) bands of V3 regions in 16S rDNAs. In the digester, most bacterial and archaeal species were uncultured; bacteria belonging to Firmicutes, Bacteroides and Spirochaetes seem to take charge of cellulolysis, proteolysis, acidogenesis, sulfur-reducing and homoacetogenesis; the most methanogens were typical hydrogenotrophic or hydrogenotrophic/aceticlastic; DGGE profiles reflected the dominant microbiota. This study gave a first insight of the overall microbial structure in a rural biogas digester and also indicated DGGE was useful in displaying its dominant microbiota.
Biodegradable metals have attracted considerable attentions in recent years. Besides the early launched biodegradable Mg and Fe metals, Zn, an essential element with osteogenic potential of human ...body, is regarded and studied as a new kind of potential biodegradable metal quite recently. Unfortunately, pure Zn is soft, brittle and has low mechanical strength in the practice, which needs further improvement in order to meet the clinical requirements. On the other hand, the widely used industrial Zn-based alloys usually contain biotoxic elements (for instance, ZA series contain toxic Al elements up to 40 wt.%), which subsequently bring up biosafety concerns. In the present work, novel Zn-1X binary alloys, with the addition of nutrition elements Mg, Ca and Sr were designed (cast, rolled and extruded Zn-1Mg, Zn-1Ca and Zn-1Sr). Their microstructure and mechanical property, degradation and in vitro and in vivo biocompatibility were studied systematically. The results demonstrated that the Zn-1X (Mg, Ca and Sr) alloys have profoundly modified the mechanical properties and biocompatibility of pure Zn. Zn-1X (Mg, Ca and Sr) alloys showed great potential for use in a new generation of biodegradable implants, opening up a new avenue in the area of biodegradable metals.
We clarify the physical origin of the dc voltage generation in a bilayer of a conducting polymer film and a micrometer-thick magnetic insulator Y_{3}Fe_{5}O_{12} (YIG) film under ferromagnetic ...resonance and/or spin wave excitation conditions. The previous attributed mechanism, the inverse spin Hall effect in the polymer Nat. Mater. 12, 622 (2013)NMAACR1476-112210.1038/nmat3634, is excluded by two control experiments. We find an in-plane temperature gradient in YIG which has the same angular dependence with the generated voltage. Both vanish when the YIG thickness is reduced to a few nanometers. Thus, we argue that the dc voltage is governed by the Seebeck effect in the polymer, where the temperature gradient is created by the nonreciprocal magnetostatic surface spin wave propagation in YIG.
The complicated structure of the neutron cannot be calculated using first-principles calculations due to the large colour charge of quarks and the self-interaction of gluons. Its simplest structure ...observables are the electromagnetic form factors1, which probe our understanding of the strong interaction. Until now, a small amount of data has been available for the determination of the neutron structure from the time-like kinematical range. Here we present measurements of the Born cross section of electron–positron annihilation reactions into a neutron and anti-neutron pair, and determine the neutron’s effective form factor. The data were recorded with the BESIII experiment at centre-of-mass energies between 2.00 and 3.08 GeV using an integrated luminosity of 647.9 pb−1. Our results improve the statistics on the neutron form factor by more than a factor of 60 over previous measurements, demonstrating that the neutron form factor data from annihilation in the time-like regime is on par with that from electron scattering experiments. The effective form factor of the neutron shows a periodic behaviour, similar to earlier observations of the proton form factor. Future works—both theoretical and experimental—will help illuminate the origin of this oscillation of the electromagnetic structure observables of the nucleon.Form factors encode the structure of nucleons. Measurements from electron–positron annihilation at BESIII reveal an oscillating behaviour of the neutron electromagnetic form factor, and clarify a long-standing photon–nucleon interaction puzzle.
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