714 research outputs found
Plasma Electrolytic Oxidation (PEO) layers from silicate/phosphate baths on Ti-6Al-4V for biomedical components: Influence of deposition conditions and surface finishing on dry sliding behaviour
Plasma Electrolytic Oxidation (PEO) layers were produced on Ti-6Al-4V in different conditions, so as to assess the influence of layer structure, current mode, duty cycle and surface finishing on microstructural features and tribological behavior. In DC regime, the double-layer structure (silicate bath followed by phosphate bath) beneficially affected wear resistance. In unipolar pulsed DC (phosphate bath), the wear resistance of single layers improved with increasing duty cycle, due to improved microstructure and adhesion: high duty cycle single layers can be considered an alternative to double-layer deposition. Surface finishing by abrasive blasting with spheroidal glass beads leads to surface roughness decrease and hence to decreased friction and improved wear resistance. The best-performing PEO layers showed promising results in the comparison with reference materials such as CoCrMo (both uncoated and (Ti,Nb)N PVD-coated) and PVD-coated Ti-6Al-4V up to 30 N normal load
Robotic or three-dimensional (3D) laparoscopy for right colectomy with complete mesocolic excision (CME) and intracorporeal anastomosis? A propensity score-matching study comparison
Background: We describe our preliminary experience in complete mesocolic excision (CME) with central vascular ligation (CVL) and intracorporeal anastomosis for right colon cancer, comparing the robotic and the three-dimensional (3D) laparoscopic approach. Methods: We performed a retrospective observational clinical cohort study on patients who underwent radical curative surgical resection of right colon cancer with CME from January 2014 to June 2019. Propensity scores were calculated by bivariate logistic regression, including the following variables: age, BMI, and size of tumor. Results: Fifty-five patients underwent CME with CVL: 26 by means of robot-assisted surgery and 29 by means of 3D laparoscopic procedure. There were not statistically significant differences about all the intra- and postoperative outcomes (operative time, length of the specimen, time to bowel canalization, time to soft oral intake, length of hospital stay, postoperative complication, number of retrieved lymph nodes, number of positive lymph nodes and lymph node ratio) between the robotic and the 3D laparoscopic approach. After the matching procedure, 20 patients of the robotic group and 20 patients of the 3D laparoscopic group were selected for the analysis. There were no differences in any of the analyzed variables between the two groups except for longer operative time in the robotic group (p = 0.002). Conclusion: The 3D vision revealed an important advantage in order to achieve the correct identification of surgical anatomy allowing a safe and effective right colectomy with CME, CVL, and intracorporeal anastomosis, either using laparoscopic or with robotic approach, providing similar short-term outcomes. Taking into account the high costs and the longer operative time of robotic procedure, the 3D laparoscopy could be considered in performing right colectomy with CME, while the robotic approach should be considered as a first choice approach for challenging situations (obese patient, complex associated procedures)
Management Zones Delineation through Clustering Techniques Based on Soils Traits, NDVI Data, and Multiple Year Crop Yields
Availability of georeferenced yield data involving different crops over years, and their use in future crop management, are a subject of growing debate. In a 9 hectare field in Northern Italy, seven years of yield data, including wheat (3 years), maize for biomass (2 years), sunflower, and sorghum, and comprising remote (Landsat) normalized difference vegetation index (NDVI) data during central crop stages, and soil analysis (grid sampling), were subjected to geostatistical analysis (semi-variogram fitting), spatial mapping (simple kriging), and Pearson’s correlation of interpolated data at the same resolution (30 m) as actual NDVI values. Management Zone Analyst software indicated two management zones as the optimum zone number in multiple (7 year) standardized yield data. Three soil traits (clay content, total limestone, total nitrogen) and five dates within the NDVI dataset (acquired in different years) were shown to be best correlated with multiple-and single-year yield data, respectively. These eight parameters were normalized and combined into a two-zone multiple soil and NDVI map to be compared with the two-zone multiple yield map. This resulted in 83% pixel agreement in the high and low zone (89 and 10 respective pixels in the soil and NDVI map; 73 and 26 respective pixels in the yield map) between the two maps. The good agreement, which is due to data buffering across different years and crop types, is a good premise for differential management of the soil-and NDVI-based two zones in future cropping seasons
Building a biomimetic membrane for neutron reflectivity investigation : complexity, asymmetry and contrast
The preparation and investigation of model membranes is deserving growing interest both for the physics of complex systems, and for biology. The need of simplified models should preserve mimicking the qualifying characteristics of biological membranes, and keep non-invasive and detailed description. As a main feature, biological membranes are non-homogeneous in the disposition of components, both in the lateral and in the transverse direction. We prepared asymmetric supported membranes containing GM1 ganglioside in biomimetic proportion according to different protocols. Then, we studied their internal structure by neutron reflectometry, providing few-Angstrom sensitivity in the cross direction meanwhile avoiding radiation damage. This technique can also be profitably applied to study interactions at the membrane surface. The best protocol has proven to be the Langmuir-Blodgett/Langmuir-Schaefer depositions. Notably, also the simpler and most accessible protocol of vesicle fusion was found to be suitable for straightforward and good quality deposition of compositionally asymmetric membranes
Pretransplant recipient blood CD14+ preDC levels correlate with increased acute GVHD after allogeneic PBSC transplantation
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Treatment and long-term results in children with acute myeloid leukaemia treated according to the AIEOP AML protocols
Segnalazione di un nuovo ittiosauro dal Cretaceo dell’Appennino modenese (Pavullo nel Frignano)
Alcuni frammenti vertebrali di ittiosauro sono stati recentemente rinvenuti in un calanco presso Pa- vullo nel Frignano (MO). I fossili sono stati trovati entro la Formazione delle Argille Varicolori di Cassio, datate al Cenomaniano superiore-Campaniano (Cretaceo). Tra i reperti rinvenuti è impor- tante segnalare un tratto di colonna vertebrale ancora parzialmente articolata. Si tratta del primo ritrovamento di questo tipo in Italia per quanto riguarda gli ittiosauri del Cretaceo. Alcuni dei corpi vertebrali in oggetto sono di dimensioni relativamente grandi, paragonabili a quelle già note per alcune specie di Platypterygiinae quali Platypterygius australis e P. americanus.Some vertebral fragments of ichthyosaur have recently been found in a clay badland near Pavullo nel Frignano (Modena Province). The finds were discovered in the “Argille Varicolori di Cassio” Formation, which dates from the upper Cenomanian-Campanian (Cretaceous). Among the fossils recovered, a portion of vertebral column, still partially articulated, is of outstanding importance. This is the first discovery of an articulated portion of a skeleton of a Cretaceous ichthyosaur in Italy. Some of the centra are relatively large, comparable to those already known for some species of Platypterygiinae such as Platypterygius australis and P. americanus
118: Elevated CD14+ Cell Dose in Marrow Graft Correlates with Increased Mortality after Allogeneic Transplantation
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392: Delayed Recovery of Myeloid (mDC) and Plasmacytoid (pDC) Dendritic Cells at 3 Months after Allogeneic HSC Transplantation Correlates with an Increased Transplant-related and Overall Mortality Independently of GVHD
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Effects of serum proteins on corrosion behavior of ISO 5832–9 alloy modified by titania coatings
Stainless steel ISO 5832–9 type is often used to
perform implants which operate in protein-containing physiological
environments. The interaction between proteins and
surface of the implant may affect its corrosive properties. The
aim of this work was to study the effect of selected serum
proteins (albumin and γ-globulins) on the corrosion of ISO
5832–9 alloy (trade name M30NW) which surface was modified
by titania coatings. These coatings were obtained by sol–
gel method and heated at temperatures of 400 and 800 °C. To
evaluate the effect of the proteins, the corrosion tests were
performed with and without the addition of proteins with
concentration of 1 g L−1 to the physiological saline solution
(0.9 % NaCl, pH 7.4) at 37 °C. The tests were carried out
within 7 days. The following electrochemical methods were
used: open circuit potential, linear polarization resistance, and
electrochemical impedance spectroscopy. In addition, surface
analysis by optical microscopy and X-ray photoelectron spectroscopy
(XPS) method was done at the end of weekly corrosion
tests. The results of corrosion tests showed that M30NW
alloy both uncoated and modified with titania coatings exhibits
a very good corrosion resistance during weekly exposition
to corrosion medium. The best corrosion resistance in
0.9 % NaCl solution is shown by alloy samples modified by
titania coating annealed at 400 °C. The serumproteins have no
significant effect onto corrosion of investigated biomedical
steel. The XPS results confirmed the presence of proteins on
the alloy surface after 7 days of immersion in proteincontaining
solutions.The investigations were supported by the National Science Centre project No. N N507 501339. The authors gratefully acknowledge Dr. Janusz
Sobczak and Dr. hab. Wojciech Lisowski from Institute of Physical
Chemistry of PAS for XPS surface analyses
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