On a model of multiphase flow

We consider a hyperbolic system of three conservation laws in one space variable. The system is a model for fluid flow allowing phase transitions; in this case the state variables are the specific volume, the velocity and the mass density fraction of the vapor in the fluid. For a class of initial data having large total variation we prove the global existence of solutions to the Cauchy problem.Comment: 32 pages. Revised and corrected versio

Global existence of solutions for a multi-phase flow: a bubble in a liquid tube and related cases

In this paper we study the problem of the global existence (in time) of weak, entropic solutions to a system of three hyperbolic conservation laws, in one space dimension, for large initial data. The system models the dynamics of phase transitions in an isothermal fluid; in Lagrangian coordinates, the phase interfaces are represented as stationary contact discontinuities. We focus on the persistence of solutions consisting in three bulk phases separated by two interfaces. Under some stability conditions on the phase configuration and by a suitable front tracking algorithm we show that, if the BV-norm of the initial data is less than an explicit (large) threshold, then the Cauchy problem has global solutions

Global existence of solutions for a multi-phase flow: a drop in a gas-tube

In this paper we study the flow of an inviscid fluid composed by three different phases. The model is a simple hyperbolic system of three conservation laws, in Lagrangian coordinates, where the phase interfaces are stationary. Our main result concerns the global existence of weak entropic solutions to the initial-value problem for large initial data

Global weak solutions for a model of two-phase flow with a single interface

We consider a simple nonlinear hyperbolic system modeling the flow of an inviscid fluid. The model includes as state variable the mass density fraction of the vapor in the fluid and then phase transitions can be taken into consideration; moreover, phase interfaces are contact discontinuities for the system. We focus on the special case of initial data consisting of two different phases separated by an interface. We find explicit bounds on the (possibly large) initial data in order that weak entropic solutions exist for all times. The proof exploits a carefully tailored version of the front tracking scheme

Door-to-needle time in acute ischemic stroke: analysing intra-hospital delays, predictive factors, improving strategies. The experience of Baggiovara hospital (MO, Italy)

Stroke is a syndrome characterized by a sudden and quick development of neurological deficits due to vascular cause. The loss of function could be global, with permanent symptoms, until death, or transient (TIA) if blood supply is rapidly restore. International Task Force defined this acute pathology “a preventable and treatable catastrophe”: it is the third cause of death in developing countries, accounting for 2-4% of the public health budget. Management strategies include: Primary prevention: public information in order to increaseawareness Acute phase management, from the activation of the emergency service tothe rehabilitation and early secondaryprevention Health care for survivors withdisability The starting point of this study is the concept that “time is brain”, enhancing the role of the interval between the onset of symptoms and the final treatment (the “door to needle time”, DNT). This led us to carry a retrospective critical analysis, evaluate the DNT before and after the introduction of an internal protocol, aiming at the standards suggested in literature

Dynamic contrast-enhanced ultrasonography (D-CEUS) for the early prediction of bevacizumab efficacy in patients with metastatic colorectal cancer

Objectives: To investigate early changes in tumour perfusion parameters by dynamic contrast-enhanced ultrasonography (D-CEUS) and to identify any correlation with survival and tumour response in patients with metastatic colorectal cancer (CRC) treated with bevacizumab (B). Methods: Thirty-seven patients randomized to either chemotherapy (C) plus B or C alone were considered for this study. D-CEUS was performed at baseline and after the first treatment cycle (day 15). Four D-CEUS perfusion parameters were considered: derived peak intensity (DPI), area under the curve (AUC), slope of wash-in (A) and time to peak intensity (TPI). Results: In patients treated with C plus B, a ≥22.5 % reduction in DPI, ≥20 % increase in TPI and ≥10 % reduction in AUC were correlated with higher progression-free survival in the C+B arm (p = 0.048, 0.024 and 0.010, respectively) but not in the C arm. None of the evaluated parameter modifications had a correlation with tumour response or overall survival. Conclusions: D-CEUS could be useful for detecting and quantifying dynamic changes in tumour vascularity as early as 15 days after the start of B-based therapy. Although these changes may be predictive of progression-free survival, no correlation with response or overall survival was found. Key Points: • D-CEUS showed early changes in liver metastasis perfusion in colorectal cancer. • A decrease in tumour perfusion was associated with longer progression-free survival. • The decrease in perfusion was not correlated with higher overall survival

Rumen fluid, a new diagnostic matrix in dairy cattle farms?

Production diseases of dairy cows are considered man-made problems caused by the inability of cowsto achieve a sufficient feed energy intake (Mulligan, 2008).A correct management of production diseases demands early diagnostic and prognostic parameters, inorder to improve the management system and reduce the prevalence of clinical cases (Ingvartsen,2003).A previous study of our group indicated that forestomachs walls express immune receptors andcytokines, and the rumen liquor contains leukocytes able to produce IFN-γ (Trevisi, 2014).Our working hypothesis implied that ruminal fluids could be a source of diagnostic information for theidentification of herds at risk for production diseases.We first demonstrated that the diet can influence the immune response in forestomachs. Diverseleukocyte populations at low concentrations and IFN-γ were revealed in some samples of rumen fluids,with a clear inhibition of the response observed in the animals fed the maize-supplemented diet,compared to a normal and a soy-supplemented diet.We better characterized the leukocytes subpopulations in the rumen liquor, isolating B cells, monocytesand γδT cells.Finally we performed a field survey in order to find correlation among the immune profile of the rumenliquor. Clinically healthy animals showed a farm specific immunologic pattern of the rumen liquor: lowCD45 mRNA expression, low IFN-γ, few/absent B-cells.We can conclude that the epithelial cells of ruminant forestomachs can react to different stresses(metabolic, infectious, inflammatory) and the inflammatory response can be sustained by infiltratingleukocytes.Our data points into the idea that dairy farms could be ranked according to a risk score using theinflammatory markers in rumen fluids, in addition to the traditional analysis.

Long-term complete response in a patient with liver metastases from breast cancer treated with metronomic chemotherapy

Background. Preclinical studies have shown that several chemotherapeutic agents at low doses may affect the vascular system. Here we report the case of a patient with long-term cancer control by metronomic chemotherapy. Case presentation. A 62-year-old woman with breast cancer underwent a left mastectomy in July 2007. For a liver metastasis she was given first-line chemotherapy with doxorubicin plus paclitaxel every 21 days. A CT scan after the sixth cycle showed a partial response. It was decided to stop the treatment with doxorubicin and paclitaxel, and start metronomic therapy with cyclophosphamide 50 mg daily orally and methotrexate 2.5 mg twice daily, 2 days a week. After 6 months of this maintenance treatment, CT scan showed a complete response. We examined the expression of vascular endothelial growth factor receptor 2 (VEGFR2) in histological sections of the primary tumor of our patient, finding evidence of overexpression of the receptor. The metronomic treatment is still ongoing, and after 60 months the patient maintains a complete response. Conclusion. This clinical case highlights how suitable metronomic chemotherapy can be used as maintenance therapy, allowing long-term treatment with no significant toxicity. This case suggests that the level of VEGFR2 is predictive of best response to antiangiogenic therapy

Monensin controlled-release capsule administered in late-pregnancy differentially affects rumination patterns, metabolic status, and cheese-making properties of the milk in primiparous and multiparous cows

The increased resistance to disease observed after monensin treatment could reflect a reduction of inflammation and oxidative stress. We hypothesised that if monensin supplementation was given before calving, it would help in controlling inflammation, reduce the susceptibility to disease and increase the performance. Fourteen pregnant heifers (PR) and 24 multiparous cows (ML) were randomly assigned to a treated group (Mon) or a control group (Ctr). The Mon group received 32.4 g of monensin in a controlled-release capsule 21 days before calving (expected release rate, 335 mg/d for 95 days). Their health status, rumination activity, and plasma parameters were monitored from –28 to 56 days from calving. The milk yield (MY), milk composition, and cheese-making properties were also monitored. Rumen samples were collected at 30 days from calving to assess the volatile fatty acids composition and investigate immunological parameters. After calving, the Mon group had fewer clinical diseases, an increased rumination time, and a higher MY. Monensin reduced the infiltration of both T and B cells in rumen fluid. In ML, the Mon group had lower levels of β-hydroxybutyrate in the early postpartum period and a lower level of total reactive oxygen species. Of PR, the Mon group had a tendency for lower levels of nonesterified fatty acids, higher levels of ceruloplasmin after the first month of lactation, a tendency for lower levels of paraoxonase, higher levels of γ-glutamyl transferase and higher levels of total reactive oxygen species. Monensin treatment decreased the cheese-making properties in the milk of PR.HighlightsMonensin improved the performance of all the animals and decreased the disease incidence in all of them.Monensin heightened the inflammatory and oxidative stress status and reduced the cheese-making properties in pregnant heifers.Although different effects were seen in cows with different parity, dairy cows generally beneficed of monensin administration. Monensin improved the performance of all the animals and decreased the disease incidence in all of them. Monensin heightened the inflammatory and oxidative stress status and reduced the cheese-making properties in pregnant heifers. Although different effects were seen in cows with different parity, dairy cows generally beneficed of monensin administration