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Background The most significant prognostic factors for pancreatic head carcinoma (PHC) with pancreaticoduodenectomy (PD) are the resection margin and lymph node status. The curative surgical margin (R0) and complete clearance of regional lymph nodes contribute to the improvement of survival. To reduce microscopic residual tumor resection (R1) and achieve a complete lymphadenectomy around the superior mesenteric artery (SMA) when performing a PD for PHC, we propose a new concept of a total excision of the “meso-pancreatoduodenum.” which consists of a cluster of the soft connective tissue along the inferior pancreaticoduodenal artery and the first jejunal artery. Methods A total of 39 consecutive patients underwent a PD for PHC between May 2006 and August 2011 at Shimane University Hospital. Twenty-five patients received a standard PD (sPD), while 14 cases underwent a total meso-pancreatoduodenum excision (tMPDe) with PD. Results The tMPDe procedure was performed safely without any intraoperative complications. The total number of lymph nodes dissected was 18 (median, range: 5–40) in the sPD and 26 (median, range: 13–50) in the tMPDe ( p = 0.027). R0 resection was accomplished in 60% and 93% of patients with the sPD and tMPDe, respectively, resulting in a significant decrease in the R1 rate in the tMPDe (7%) compared to that in the sPD (40%) ( p = 0.019). No loco-regional recurrence was found around the SMA in the tMPDe patients. Conclusion Our surgical technique, tMPDe, is safe and more radical when performing a PD and should be adopted when performing pancreatic surgery as a pathological cure for pancreatic head carcinoma.

With this paper we propose a detailed study of the gradual degradation of InGaN-based laser diodes and Light-Emitting Diodes submitted to electro-thermal stress. The two device structures have been processed from the same epitaxial wafer. Our purpose is to compare the behavior of the two devices by means of electro-optical measurements, electroluminescence characterization, and near field emission measurements. We demonstrate that: (i) stress induces a decrease in the optical power and an increase in threshold current; (ii) the two failure modes are strictly linked each other, and correlated to the increase in defect-related current components, indicating a substantial increase in defect density during degradation; (iii) analysis of characteristic temperature and near-field emission measurements do not indicate any strong variation of injection efficiency nor current confinement of the devices.

International audience; The mesopelagic zone is the oceanic region through which carbon and other elements must pass in order to reach deeper waters or the sea floor. However, the food web interactions that occur in the mesopelagic zone are difficult to measure and so, despite their crucial importance to global elemental cycles, are not very well known. Recent developments in technology and new approaches have advanced the study of the variability in and controls upon the distribution and diversity of organisms in the mesopelagic zone, including the roles of respiration, recycling, and repackaging of particulate and dissolved organic material. However, there are remarkably few syntheses of the ecology and biogeochemistry of the microbes and metazoa that permanently reside or habitually visit this 'twilight zone'. Without this synthesis, it is difficult to assess the impact of ongoing changes in ocean hydrography and chemistry, due to increasing atmospheric carbon dioxide levels, on the biological carbon pump. This paper reviews what is known about the distribution of microbes and metazoa in the mesopelagic zone in relation to their activity and impact on global biogeochemical cycles. Thus, gaps in our knowledge are identified and suggestions made for priority research programmes that will improve our ability to predict the effects of climate change on carbon sequestration. (C) 2010 Elsevier Ltd. All rights reserved.

In order to test the hypothesis of P-limitation on primary production and microbial biomass, a mesoscale Lagrangian phosphate-enrichment experiment was performed in the warm core of the Cyprus Eddy (Eastern Mediterranean Sea) in May 2002. This study reports the effects of the phosphate addition on the phytoplankton community, by measuring induced changes in biomass, primary production, and community structure. Prior to the addition, primary production and chlorophyll a were very low ( 0.107 μ gC l - 1 h - 1 and 18 ng l - 1 , respectively), typical of the ultra-oligotrophic conditions prevailing in the area. The autotrophic community was dominated in terms of both abundance and biomass (60% of total chl- a ) by picoplankton (mostly Synechococcus). More than 90% of the autotrophic biomass was confined to particles 10 μ m , while larger phytoplankton (diatoms, dinoflagellates, coccolithophores) were very scarce. Unexpectedly, the addition of P resulted in a decrease in phytoplankton biomass. Total HPLC-chlorophyll slightly declined to 11 ng l - 1 in the P-enriched patch, five days after the P-addition. As the patch was diluted away (7–9 days), chlorophyll concentrations returned to background levels. Similar trends were observed in chlorophyll determined fluorometrically and in primary production. Picophytoplankton and smaller nanophytoplankton abundance declined (by 49 and 65%, respectively) within the first four days of the experiment. At the same time, there was a small increase of larger nanophytoplankton (10– 20 μ m ) and microphytoplankton ( > 20 μ m ) species. Small nanophytoplankton (2– 10 μ m ) were the group most affected by the addition. These results together with an onboard microcosm experiment (reported elsewhere in this issue), in which ammonia was added to the P-enriched water, indicate that the system was N and P co-limited for phytoplankton. The decrease in pico and smaller nanophytoplankton was probably caused by increased predation by micrograzers that became more active because of the increased heterotrophic bacterial activity and/or the increased P content of their prey. The immediate decrease in Synechococcus numbers, as the system became temporarily N-limited implies that N-fixation caused by this particular cyanobacteria was unlikely to occur.

A three-dimensional (3D) high-resolution MHD simulation scheme on an unstructured grid system is developed for inhomogeneous systems, including strong background potential fields. The scheme is based on the finite volume method (FVM) with an upwinding numerical flux by the linearized Riemann solver. Upwindings on an unstructured grid system are realized from the fact that the MHD equations are symmetric with the rotation of the space. The equation system is modified to avoid direct inclusions of the background potential field as a dependent variable, through the use of changed dependent variables. Despite such a change of the equation system, the eigenvectors in the mode-synthesis matrix that are necessary for the evaluation of the upwinding numerical flux vectors can still be written analytically. The eigenvalues of the MHD flux Jacobian matrix that are also necessary for the upwinding calculations are derived from the well-known Alfven, fast and slow, velocities. The calculations of the eigen vectors is done with special care when the wave propagations become parallel or perpendicular to the ambient magnetic field, because degeneration of the eigenvalues occurs in these cases. To obtain a higher order of accuracy, the upwinding flux is extended to the second-order TVD numerical flux in the calculation of FVM, through the MUSCL approach and Van Leer's differentiable limiter. In order to show the efficiency of the above scheme, a numerical example is given for the interaction process of high-β supersonic plasma flow with the region of a strong dipole field, including magnetized low-β plasma.

acute clinical hepatitis C. However, only HCV-specific IL-10 response correlatedwith elevated liver enzymes, increased viremia and suppressed HCV-specific CD4+ T-cell proliferation in acute infection. While these associations were lost in established chronic infection, HCVspecific IL-10 responses were increased in patients without cirrhosis while IL-10 blockade enhanced antiviral effector IFNγ responses. Conclusions: HCV-specific IL-10 Tr1 responses may play a dual role in HCV infection, dampening effector T-cells to promote viral persistence in acute infection but also protecting against progressive fibrosis in chronic infection.

A thin-layer chromatographic screening procedure for some basic, neutral and acidic drugs was developed using 3 ml of horse plasma. Chloroform-2-propanol (95:5, v/v) was used as the extraction solvent. The drugs were identified by a high-performance thin-layer chromatographic plate and spraying successively with some detection reagents. In this study, the extraction recovery rates and the detection limits were determined at the same time.

This paper concerns a buble volume method derived from the maximum bubble pressure method for measurement of surface tension of liquids. This new, simple method is based on a steady-state expansion of a single air bubble formed on the bubble tip turned upward in liquid until detachment from the tip; through measurement of the detached bubble volume, the liquid surface tension is obtained. The empirical relationship between the volume and the expanding time obtained for several pure liquids and aqueous solutions was found to be very similar to that between the drop weight (or volume) and the dropping time obtained by the drop weight technique. The analytical treatment of the experimental data gives the dynamic surface tension of C12E5 (dodecyl pentaethylene glycol) solutions. Evaluation with the adsorption equation for surface dilatation showed that the dynamic surface tension obeys diffusion-controlled adsorption kinetics as expected.