Satellite interferometric data for seismic damage assessment

Radar satellites allow the collection of data on large areas without direct access to structures. Thereby, they appear very attractive for Structural Health Monitoring (SHM) purposes. Data collected by satellites can be processed to obtain temporal histories of displacements through which the health state of a monitored system can be potentially identified. However, anomalies in the time histories of displacements are not necessarily due to damage. Environmental phenomena, such as variations in atmospheric temperature, and rain, can modify the behavior of structures without compromising their safety. The impact of these phenomena on the structural response can hinder the identification of anomalies or lead to false alarms if such alterations are misinterpreted as damage. Furthermore, if the monitored system is a historical structure, uncertainties on the structural behavior are inevitably increased during aging. The purpose of this article is to discuss the possibility of identifying damage due to seismic actions considering the impact of variations of environmental factors on the time histories of the displacements retrieved by satellite data. The structural health condition of a historical structure located in the city of Rome (Italy) hit by the October 2016 Central Italy earthquakes is investigated based on interferometric satellite data. The satellite data are acquired by COSMO-SkyMed (CSM) of the Italian Space Agency between 2010 and 2019 and are processed by CNR IREA

Quadratic dependence on temperature of Cs 0-0 hyperfine resonance frequency in single Ne buffer gas microfabricated vapour cell

Presented is the observation of a quadratic temperature dependence of the Cs 0-0 ground state hyperfine resonance frequency in a single Neon (Ne) buffer gas vapour microcell. The inversion temperature, expected to be theoretically independent of the buffer gas pressure, is measured to be about 80-C for two different samples. A proposal to develop chip scale atomic clocks with improved long-term frequency stability, simpler configuration (a single buffer gas instead of a buffer gas mixture) and then relaxed constraints on pressure accuracy during the cell filling procedure is presented

Molecular Sensing by Nanoporous Crystalline Polymers

Chemical sensors are generally based on the integration of suitable sensitive layers and transducing mechanisms. Although inorganic porous materials can be effective, there is significant interest in the use of polymeric materials because of their easy fabrication process, lower costs and mechanical flexibility. However, porous polymeric absorbents are generally amorphous and hence present poor molecular selectivity and undesired changes of mechanical properties as a consequence of large analyte uptake. In this contribution the structure, properties and some possible applications of sensing polymeric films based on nanoporous crystalline phases, which exhibit all identical nanopores, will be reviewed. The main advantages of crystalline nanoporous polymeric materials with respect to their amorphous counterparts are, besides a higher selectivity, the ability to maintain their physical state as well as geometry, even after large guest uptake (up to 10–15 wt%), and the possibility to control guest diffusivity by controlling the orientation of the host polymeric crystalline phase. The final section of the review also describes the ability of suitable polymeric films to act as chirality sensors, i.e., to sense and memorize the presence of non-racemic volatile organic compounds

First experience with sildenafil after Fontan operation: short-term outcomes.

Background We conducted a retrospective study to determine the effect of oral sildenafil administrated as monotherapy after Fontan operation in single ventricle physiology. Methods From January 2008 to March 2012, during two different periods, a total of 30 pediatric patients undergoing Fontan operation by extracardiac conduit were included in this study. Thirteen patients were in the sildenafil group and exclusively treated with sildenafil given at the dose of 0.35 mg/kg through a nasogastric tube and then orally every 4 h, at the start of cardiopulmonary bypass and for the first postoperative week; then we reduced and discontinued the therapy. The other 17 patients were in the control group. No other vasodilator was administered in both groups. We analyzed intraoperative and postoperative outcomes of sildenafil administration. Results There were no differences in mortality or operative time. The total and relative drainage loss was lower in the sildenafil group (PU0.0003 and 0.0045). The hemodynamic parameters showed a better condition in the sildenafil group, with a lower mean pulmonary artery pressure (mPAP) (PU0.0001) and better mPAP to mean systemic blood pressure (mSBP) ratio (PU0.0043), whereas there was no difference in peripheral oxygen saturation (PU0.31). The sidenafil group patients showed other additional positive differences as well as lower inotropic score (PU0.0005) and intubation time (PU0.0004). No complications related to the use of sildenafil were noted in any of the children studied. Conclusion This initial experience provides evidence that sildenafil may be used in postoperative Fontan operation with positive effectiveness

Tranexamic acid therapy in pediatric cardiac surgery:a single center study

Background: We conducted a retrospective study of cyanotic and acyanotic patients undergoing cardiopulmonary bypass to determine the effect of tranexamic acid on blood loss and blood products administered during the operation in pediatric cardiac surgery. Methods: From January 2008 to December 2011, during 2 different periods, a total of 231 pediatric patients undergoing cardiac surgery with cardiopulmonary bypass (123 cyanotic, 108 acyanotic) were included in this study. A total of 104 patients were in the antifibrinolytic group and exclusively treated with tranexamic acid that was given as a bolus of 20 mg/kg-1 after anesthetic induction and 20 mg/kg-1 after protamine. The other 127 patients were in the control group. We analyzed intraoperative and postoperative outcomes of tranexamic acid administration. Results: There were no differences in mortality or operative time, but blood loss in 48 hours was greater in the control group (p = 0.0012). A significant difference was found in the amount of intraoperative erythrocyte concentrate transfused (140 ± 55 vs 170 ± 78 mL, p = 0.0011) but not in number. The number and amount of erythrocyte concentrate transfused in the first 48 postoperative hours were also greater in the control group (45 vs 77 patients, p = 0.012; 100 ± 40 vs 120 ± 55 mL, p = 0.0022). There were not many differences in the effect of tranexamic acid between the cyanotic and acyanotic subgroup. Conclusions: This retrospective study provides evidence that tranexamic acid may be used in the field of congenital cardiac surgery effectively

In vitro generation of pancreatic endocrine cells from human adult fibroblast-like limbal stem cells

Stem cells might provide unlimited supply of transplantable cells for β-cell replacement therapy in diabetes. The human limbus is a highly specialized region hosting a well-recognized population of epithelial stem cells, which sustain the continuous renewal of the cornea, and the recently identified stromal fibroblast-like stem cells (f-LSCs), with apparent broader plasticity. However, the lack of specific molecular markers for the identification of the multipotent limbal subpopulation has so far limited the investigation of their differentiation potential. In this study we show that the human limbus contains uncommitted cells that could be potentially harnessed for the treatment of diabetes. Fourteen limbal biopsies were obtained from patients undergoing surgery for ocular diseases not involving the conjunctiva or corneal surface. We identified a subpopulation of f-LSCs characterized by robust proliferative capacity, expressing several pluripotent stem cell markers and exhibiting self-renewal ability. We then demonstrated the potential of f-LSCs to differentiate in vitro into functional insulin-secreting cells by developing a four-step differentiation protocol that efficiently directed f-LSCs towards the pancreatic endocrine cell fate. The expression of specific endodermal, pancreatic, islet, and β-cell markers, as well as functional properties of f-LSC-derived insulin-producing cells, were evaluated during differentiation. With our stage-specific approach, up to 77% of f-LSCs eventually differentiated into cells expressing insulin (also assessed as C-peptide) and exhibited phenotypic features of mature β-cells, such as expression of critical transcription factors and presence of secretory granules. Although insulin content was about 160-fold lower than what observed in adult islets, differentiated cells processed ∼98% of their proinsulin content, similar to mature β-cells. Moreover, they responded in vitro in a regulated manner to multiple secretory stimuli, including glucose. In conclusion, f-LSCs represent a possible relevant source of autologous, transplantable, insulin-producing cells that could be tested for the reversal of diabetes