Comparison of the Results of Analytical and Numerical Models of Pre-Reinforcement in Shallow Tunnels

AbstractThe steel pipe umbrella is a widely used technology when tunnelling in weak soils in order to create pre-support ahead of the tunnel face. The design of steel pipes is frequently done through simplified analytical approaches which are easy to apply but require proper assessment of the loads acting on the pipe. To provide information on this key design aspect, the results of the comparison between a three-dimensional numerical model developed with the code FLAC 3D and an analytical model based on the approach of a beam on yielding supports is presented and discussed. The comparison refers to a shallow tunnel with an overburden of three times its diameter for two different types of weak rock masses. The obtained results provide suggestions about the load that has to be applied in the analytical model for the design phase

Long-term durability assessment of PVC-P waterproofing geomembranes through laboratory tests

Waterproofing heavily influences the operation and maintenance costs of underground structures. Currently, the most commonly used technology for tunnel waterproofing is plasticized polyvinyl chloride (PVC-P) geomembranes. However, not much is known about the long-term durability of these geomembranes, especially in relation to the long expected lifespan of new tunnels (i.e. 100–150 years). Therefore, in this paper, the durability of two commercially available PVC-P geomembranes is studied with the help of a specifically designed accelerated ageing device in addition to mechanical and absorption tests. The degradation resulting from plasticizer loss is extrapolated to the long term, and a threshold value for the end-of-life of the PVC-P geomembrane is estimated from the mechanical tests

Organic Carbon Burial following the Middle Eocene Climatic Optimum (MECO) in the central - western Tethys

We present trace metal geochemistry and stable isotope records for the middle Eocene Alano di Piave section, NE Italy, deposited during magnetochron C18n in the marginal Tethys Ocean. We identify a $\sim$ 500 kyr long carbon isotope perturbation event we infer to be the middle Eocene Climatic Optimum (MECO) confirming the northern hemisphere expression and global occurrence of MECO. Interpreted peak climatic conditions are followed by the rapid deposition of two organic rich intervals ($\le$3\% TOC) and contemporaneous positive $\delta^{13}$C excursions. These two intervals are associated with increases in the concentration of sulphur and redox-sensitive trace metals, and low concentrations of Mn, as well as coupled with the occurrence of pyrite. Together these changes imply low, possibly dysoxic, bottom water O$_{2}$ conditions promoting increased organic carbon burial. We hypothesize that this rapid burial of organic carbon lowered global {\it p}CO$_{2}$ following the peak warming and returned the climate system to the general Eocene cooling trend

Serum cardiac troponin I concentration in dogs with precapillary and postcapillary pulmonary hypertension.

Background: Pulmonary hypertension (PH) is a disease condition leading to right\u2010sided cardiac hypertrophy and, eventually, right\u2010sided heart failure. Cardiac troponin I (cTnI) is a circulating biomarker of cardiac damage. Hypothesis: Myocardial damage can occur in dogs with precapillary and postcapillary PH. Animals: One hundred and thirty\u2010three dogs were examined: 26 healthy controls, 42 dogs with mitral valve disease (MVD) without PH, 48 dogs with pulmonary hypertension associated with mitral valve disease (PH\u2010MVD), and 17 dogs with precapillary PH. Methods: Prospective, observational study. Serum cTnI concentration was measured with a commercially available immunoassay and results were compared between groups. Results: Median cTnI was 0.10\u2003ng/mL (range 0.10\u20130.17\u2003ng/mL) in healthy dogs. Compared with the healthy population, median serum cTnI concentration was increased in dogs with precapillary PH (0.25\u2003ng/mL; range 0.10\u20131.9\u2003ng/mL; P < .001) and in dogs with PH\u2010MVD (0.21\u2003ng/mL; range 0.10\u20132.10\u2003ng/mL; P < .001). Median serum cTnI concentration of dogs with MVD (0.12\u2003ng/mL; range 0.10\u20131.00\u2003ng/mL) was not significantly different compared with control group and dogs with PH\u2010MVD. In dogs with MVD and PH\u2010MVD, only the subgroup with decompensated PH\u2010MVD had significantly higher cTnI concentration compared with dogs with compensated MVD and PH\u2010MVD. Serum cTnI concentration showed significant modest positive correlations with the calculated pulmonary artery systolic pressure in dogs with PH and some echocardiographic indices in dogs with MVD and PH\u2010MVD. Conclusions and Clinical Importance: Serum cTnI is high in dogs with either precapillary and postcapillary PH. Myocardial damage in dogs with postcapillary PH is likely the consequence of increased severity of MVD

Erratum to: Proximal humeral fractures in elderly patients

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First record of Acanthurus chirurgus (Perciformes: Acanthuridae) in the Mediterranean Sea, with some distributional notes on Mediterranean Acanthuridae

The occurrence of the doctorfish Acanthurus chirurgus is reported for the first time in the Mediterranean Sea, off Elba Island, Tyrrhenian Sea (42.726667° N, 10.434444° E). This record is tentatively related to aquarium release. The occurrence of Acanthuridae in the Mediterranean Sea is briefly reviewed, and some distributional notes on Acanthurus coeruleus and Acanthurus monroviae in the Mediterranean are provided

Beyond Trial and Error: A Systematic Development of Liposomes Targeting Primary Macrophages

Monocytes/macrophages are phagocytic innate immune cells playing a pivotal role in tissue homeostasis, inflammation, and antitumor immunity in a microenvironment-dependent manner. By expressing pattern recognition and scavenger receptors on their surface, macrophages selectively take up pathogens, cellular debris, and often—undesirably—drug delivery systems. On the other hand, the propensity of phagocytic cells to internalize particulate drug carriers is used to load them with a cargo of choice, turning the monocytes/macrophages into a diagnostic or therapeutic Trojan horse. Identifying the ideal physicochemical properties of particulate carriers such as liposomes to achieve the most efficient macrophage-mediated drug delivery has been object of extensive research in the past, but the studies reported so far rely solely on trial-and-error approaches. Herein, a design of experiment (DoE) strategy to identify the optimal liposomal formulation is proposed, fully characterized in terms of size, surface charge, and membrane fluidity, to maximize macrophage targeting. The findings are validated using mouse bone marrow-derived macrophages, a primary preparation modeling in vivo monocyte-derived macrophages, thus confirming the robustness and versatility of the systematic and iterative approach and suggesting the promising potential of the DoE approach for the design of cell-targeting delivery systems