Cure after re-resection of colorectal liver metastases in a 28 year old woman. A case report

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenLiver resection is the only well documented curative treatment for colorectal liver metastases but without surgery survival is dismal. Liver resections can be done for re-metastatic colorectal cancers if the tumors are localized in the liver. The first case of re-resection of colorectal liver metastases in Iceland is presented.Lífshorfur sjúklinga sem greinast með lifrarmeinvörp frá ristilkrabbameini eru slæmar og án meðferðar eru flestir dánir innan árs (1,2). Lifrarúrnám er eina læknandi meðferðin (3). Aðgerðinni má beita við endurtekin meinvörp (4,5). Lýst er tilfelli af endurteknu lifrarhöggi hér á landi

Laparoscopic cholecystectomy. The first 400 cases at Akureyri Central Hospital

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenObjective: To assess the outcome of the first 400 laparoscopic cholecystectomies (LC) in Akureyri Central Hospital (FSA), Iceland. Methods: We carried out a prospective study of LCs performed between July 1992 and February 2001. Primary endpoints were complication- and conversion rate, hospital stay and duration of convalescence. Results: A total of 426 operations were performed in the period. In 26 cases it was decided beforehand to perform an open cholecystectomy (OC). A LC was begun on 400 patients. Indication for operation was acute cholecystitis in 41 cases (10,3%) and an elective LC was performed in 359 (89,7%) cases. Conversion to OC was required in sixteen (4%) cases with a conversion rate in acutely performed LCs of 12,2% versus 3,1% in elective LCs. Mean hospital stay after LC was 3,6 days (1-45) versus 12,3 days (4-31) after OC. Mean operation time was 89 minutes (45-270) in the first 100 LCs versus 75 minutes (30-180) in the last 100 LCs. Duration of convalescence of patients undergoing LC was 13,5 days (4-70). Complication rate in LCs was 10% (40/400). Four patients required a reoperation. Conclusions: Our results show that LC is a safe procedure in FSA. Conversion rate to OC, complication rate and duration of convalescence stands good comparison to other studies.Tilgangur: Að meta árangur við fyrstu 400 gallblöðrunám með kviðsjártækni á Fjórðungssjúkrahúsinu á Akureyri (FSA). Efniviður og aðferðir: Gerð var framsæ rannsókn á tímabilinu júlí 1992 til febrúar 2001. Tíðni fylgikvilla og breytingar yfir í opna aðgerð var athuguð, auk þess sem lengd sjúkrahúsdvalar og tími til fyrri færni voru borin saman við niðurstöður annarra sjúkrahúsa. Niðurstöður: Alls voru framkvæmd 426 gallblöðrunám á sjúkrahúsinu. Í 26 tilfellum var um hefðbundna opna aðgerð að ræða frá byrjun. Gallblöðrunám með kviðsjártækni var reynt hjá 400 sjúklingum. Hjá 41 sjúklingi (10,3%) var um að ræða aðgerð vegna bráðrar gallblöðrubólgu og 359 sjúklingar voru teknir í valaðgerð. Snúa þurfti 16 (4%) kviðsjáraðgerðum í opna aðgerð, hlutfall opnunar við bráðaaðgerðir var 12,2% á móti 3,1% við valaðgerðir. Meðalfjöldi legudaga var 3,6 dagar (1-45) eftir kviðsjáraðgerðir á móti 12,3 dögum (4-31) eftir opnar aðgerðir. Meðal aðgerðartími við fyrstu 100 kviðsjáraðgerðirnar var 89 mínútur (45-270) og 75 mínútur (30-180) við síðustu 100 aðgerðirnar. Meðalfjöldi veikindadaga eftir kviðsjáraðgerðir var 13,5 dagar (4-70). Eftir gallblöðrunám með kviðsjártækni var tíðni fylgikvilla 10% (40/400). Enduraðgerð þurfti að framkvæma hjá fjórum sjúklingum. Ályktun: Gallblöðrunám með kviðsjártækni er örugg aðgerð á FSA. Hlutfall kviðsjáraðgerða, sem breyta þurfti í opna aðgerð, tíðni fylgikvilla og færni sjúklinga stenst fyllilega samanburð við aðrar rannsóknir

Characterizing the mechanical behavior of single and polycrystalline silicon carbide using nanoindentation.

This research aims at enhancing the fundamental understanding of mechanisms controlling the deformation and fracture of silicon carbide based ceramics (single- and poly-crystal). The role of microstructure and material properties on the energy absorption capability of SiC is studied. This research helps to improve the ability to quantitatively predict the initiation and propagation of fracture and the interaction between fracture and plasticity, which provides a step towards a mechanistic understanding of deformation and failure properties of ceramic single crystals and polycrystals. The validity of the indentation-cracking method for toughness measurement is examined using nanoindentation tests with different indenters (spherical, pyramidal). Pyramidal indenters with various centerline to face angles are used to produce a wide range of effective strains in the single and polycrystalline SiC. Crystal plasticity constitutive laws can be calibrated using below threshold indentation loads. Above threshold loads are used to construct a parametric map that delineates the dependence of the ratio of crack size and contact radius on indenter geometry, applied load, toughness, and hardness, thus providing important guidelines for the toughness measurement method. By examining the behavior of several SiC materials during nanoindentation experiments using spherical and pyramidal indenters, it is possible to make predictions about methods to improve the ductility and fracture toughness of SiC to optimize its energy absorption. The applicability of the area under the irreversible part of the indentation load displacement curve (energy dissipated during loading) to predict the performance of SiC under contact loading is examined

Catalytic reactivity of face centered cubic PdZn_α for the steam reforming of methanol

Addition of Zn to Pd changes its catalytic behavior for steam reforming of methanol. Previous work shows that improved catalytic behavior (high selectivity to CO2) is achieved by the intermetallic, tetragonal L10 phase PdZnβ1, where the Pd:Zn ratio is near 1:1. The Pd–Zn phase diagram shows a number of other phases, but their steady-state reactivity has not been determined due to the difficulty of precisely controlling composition and phase in supported catalysts. Hence, the role of Zn on Pd has generally been studied only on model single crystals where Zn was deposited on Pd(1 1 1) with techniques such as TPD and TPR of methanol or CO. The role of small amounts of Zn on the steady-state reactivity of Pd–Zn remains unknown. Therefore, in this work, we have synthesized unsupported powders of phase pure PdZnα, a solid solution of Zn in fcc Pd, using a spray pyrolysis technique. The surface composition and chemical state were studied using Ambient Pressure-XPS (AP-XPS) and were found to match the bulk composition and remain so during methanol steam reforming (MSR) (Ptot = 0.25 mbar). Unlike the PdZnβ11 phase, we find that PdZnα is 100% selective to CO during methanol steam reforming with TOF at 250 °C of 0.12 s−1. Steady-state ambient pressure micro-reactor experiments and vacuum TPD of methanol and CO show that the α phase behaves much like Pd, but Zn addition to Pd improves TOF since it weakens the Pd–CO bond, eliminating the poisoning of Pd by CO during MSR over Pd. The measured selectivity for fcc PdZnα therefore confirms that adding small amounts of Zn to Pd is not enough to modify the selectivity during MSR and that the PdZnβ1 tetragonal structure is essential for CO2 formation during MSR

Eutectic Colony Formation: A Stability Analysis

Experiments have widely shown that a steady-state lamellar eutectic solidification front is destabilized on a scale much larger than the lamellar spacing by the rejection of a dilute ternary impurity and forms two-phase cells commonly referred to as `eutectic colonies'. We extend the stability analysis of Datye and Langer for a binary eutectic to include the effect of a ternary impurity. We find that the expressions for the critical onset velocity and morphological instability wavelength are analogous to those for the classic Mullins-Sekerka instability of a monophase planar interface, albeit with an effective surface tension that depends on the geometry of the lamellar interface and, non-trivially, on interlamellar diffusion. A qualitatively new aspect of this instability is the occurence of oscillatory modes due to the interplay between the destabilizing effect of the ternary impurity and the dynamical feedback of the local change in lamellar spacing on the front motion. In a transient regime, these modes lead to the formation of large scale oscillatory microstructures for which there is recent experimental evidence in a transparent organic system. Moreover, it is shown that the eutectic front dynamics on a scale larger than the lamellar spacing can be formulated as an effective monophase interface free boundary problem with a modified Gibbs-Thomson condition that is coupled to a slow evolution equation for the lamellar spacing. This formulation provides additional physical insights into the nature of the instability and a simple means to calculate an approximate stability spectrum. Finally, we investigate the influence of the ternary impurity on a short wavelength oscillatory instability that is already present at off-eutectic compositions in binary eutectics.Comment: 26 pages RevTex, 14 figures (28 EPS files); some minor changes; references adde

Eutectic colony formation: A phase field study

Eutectic two-phase cells, also known as eutectic colonies, are commonly observed during the solidification of ternary alloys when the composition is close to a binary eutectic valley. In analogy with the solidification cells formed in dilute binary alloys, colony formation is triggered by a morphological instability of a macroscopically planar eutectic solidification front due to the rejection by both solid phases of a ternary impurity that diffuses in the liquid. Here we develop a phase-field model of a binary eutectic with a dilute ternary impurity and we investigate by dynamical simulations both the initial linear regime of this instability, and the subsequent highly nonlinear evolution of the interface that leads to fully developed two-phase cells with a spacing much larger than the lamellar spacing. We find a good overall agreement with our recent linear stability analysis [M. Plapp and A. Karma, Phys. Rev. E 60, 6865 (1999)], which predicts a destabilization of the front by long-wavelength modes that may be stationary or oscillatory. A fine comparison, however, reveals that the assumption commonly attributed to Cahn that lamella grow perpendicular to the envelope of the solidification front is weakly violated in the phase-field simulations. We show that, even though weak, this violation has an important quantitative effect on the stability properties of the eutectic front. We also investigate the dynamics of fully developed colonies and find that the large-scale envelope of the composite eutectic front does not converge to a steady state, but exhibits cell elimination and tip-splitting events up to the largest times simulated.Comment: 18 pages, 18 EPS figures, RevTeX twocolumn, submitted to Phys. Rev.

Performance of Large Storage Tank in Bhuj Earthquake

The 2001 Bhuj earthquake of magnitude 7.7 caused a widespread damage in the state of Gujarat, India. This paper presents a case study of phosphoric acid storage tank weighing 100,000 kN and measuring 30 m in diameter built for a fertilizer plant in Kandla, Gujarat. The post earthquake performance assessment was carried out by exhuming the nearby piles and non-destructive testing of piles. The storage tanks supported on piles, installed in a ground treated with stone columns, showed no failure and have performed well during the earthquake. The design philosophy used to resist axial and lateral loads is explained

Lattice dynamics and specific heat of α‐helical poly(L‐alanine)

We have calculated the phonon dispersion relation in α‐poly(L‐alanine) with all atoms in the chemical repeat explicitly included and using a recently refined force field for the polypeptide chain. The phonon density of states shows very good agreement with the inelastic neutron scattering data for this polypeptide. The specific heat for T<150 K yields better agreement with experiment than did earlier calculations. At higher temperatures the discrepancy with experiment remains. We present a simple model calculation which suggests that the source of this discrepancy may lie in the anharmonicity of the methyl torsion mode.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69884/2/JCPSA6-84-12-6989-1.pd