182 research outputs found
Attack-Surface Metrics, OSSTMM and Common Criteria Based Approach to “Composable Security” in Complex Systems
In recent studies on Complex Systems and Systems-of-Systems theory, a huge effort has been put to cope with behavioral problems, i.e. the possibility of controlling a desired overall or end-to-end behavior by acting on the individual elements that constitute the system itself. This problem is particularly important in the “SMART” environments, where the huge number of devices, their significant computational capabilities as well as their tight interconnection produce a complex architecture for which it is difficult to predict (and control) a desired behavior; furthermore, if the scenario is allowed to dynamically evolve through the modification of both topology and subsystems composition, then the control problem becomes a real challenge. In this perspective, the purpose of this paper is to cope with a specific class of control problems in complex systems, the “composability of security functionalities”, recently introduced by the European Funded research through the pSHIELD and nSHIELD projects (ARTEMIS-JU programme). In a nutshell, the objective of this research is to define a control framework that, given a target security level for a specific application scenario, is able to i) discover the system elements, ii) quantify the security level of each element as well as its contribution to the security of the overall system, and iii) compute the control action to be applied on such elements to reach the security target. The main innovations proposed by the authors are: i) the definition of a comprehensive methodology to quantify the security of a generic system independently from the technology and the environment and ii) the integration of the derived metrics into a closed-loop scheme that allows real-time control of the system. The solution described in this work moves from the proof-of-concepts performed in the early phase of the pSHIELD research and enrich es it through an innovative metric with a sound foundation, able to potentially cope with any kind of pplication scenarios (railways, automotive, manufacturing, ...)
Zinc oxide nanoparticles as selective killers of proliferating cells
Background: It has recently been demonstrated that zinc oxide nanoparticles (ZnO NPs) induce death of cancerous cells whilst having no cytotoxic effect on normal cells. However, there are several issues which need to be resolved before translation of zinc oxide nanoparticles into medical use, including lack of suitable biocompatible dispersion protocols and a better understanding being needed of the mechanism of their selective cytotoxic action.
Methods: Nanoparticle dose affecting cell viability was evaluated in a model of proliferating cells both experimentally and mathematically. The key issue of selective toxicity of ZnO NPs toward proliferating cells was addressed by experiments using a biological model of noncancerous cells, ie, mesenchymal stem cells before and after cell differentiation to the osteogenic lineage.
Results: In this paper, we report a biocompatible protocol for preparation of stable aqueous solutions of monodispersed zinc oxide nanoparticles. We found that the threshold of intracellular ZnO NP concentration required to induce cell death in proliferating cells is 0.4 ± 0.02 mM. Finally, flow cytometry analysis revealed that the threshold dose of zinc oxide nanoparticles was lethal to proliferating pluripotent mesenchymal stem cells but exhibited negligible cytotoxic effects to osteogenically differentiated mesenchymal stem cells.
Conclusion: Results confirm the ZnO NP selective cytotoxic action on rapidly proliferating cells, whether benign or malignant
Laparoscopic treatment of splenic artery aneurysms
OBJECTIVES:
The purpose of this study was to report a series of 16 consecutive patients who underwent laparoscopic treatment of splenic artery aneurysms.
METHODS:
Over a period of 8 years, patients were selected for the laparoscopic option by a team of specialists that included the vascular surgeon, the interventional radiologist, and the laparoscopic surgeon. The mean size of the aneurysm was 32 mm and most was located at the splenic hilum. They were twice as common in females as in males. Ultrasonography with color Doppler function was used to define intraoperative strategy.
RESULTS:
The laparoscopic treatment entailed excision of the aneurysm or its exclusion, usually reserved for distally located lesions. In one patient, laparoscopic resection and robotic anastomosis of the splenic artery was performed to re-establish flow to the spleen. In two patients, the intraoperative decision was added to combine a laparoscopic splenectomy due to insufficient residual arterial flow to the spleen. There was no conversion, or need for re-operation or related mortality. Analysis of intraoperative arterial flow data avoided unnecessary splenectomy following noncritical reduction of flow to the spleen.
CONCLUSIONS:
The use of intraoperative color Doppler ultrasonography is essential in deciding the appropriate procedure and whether the spleen should be removed or saved. Early control of the splenic artery proximal to the aneurysm can limit the risk of conversion due to intraoperative bleeding. Distally located aneurysms are more difficult to manage and entail a higher risk of associated splenectomy. The laparoscopic option offers some advantages over the endovascular treatment in selected patients. A multidisciplinary approach is the key to a successful treatment of this uncommon disease
Spray-Coated, Magnetically Connectable Free-Standing Epidermal Electrodes for High Quality Biopotential Recordings
Acquiring biopotentials from the surface of the body is a common procedure both in the clinical practice and in non-clinical applications as sport and human- machine interfaces. To avoid bulky recording systems and to allow optimal long-term measurements, several tattooable solutions were recently developed, aiming at high-quality and imperceptible electrodes. However, a seamless connection with epidermal electrodes still represents one of the biggest challenges in this field. In this paper, we propose a simple and efficient approach for the fabrication of free-standing epidermal electrodes that can be contacted using small magnetic connectors, thus directly tackling this issue. The proposed electrodes are fabricated using a conductive ink based on poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) deposited by spray coating, and can be easily contacted using magnetic connectors without disrupting their conformability, thanks to the presence of ferrite nanoparticles integrated within the thin film itself. These electrodes have been successfully employed for the detection of different biopotentials, namely electrocardiogram, electromyogram and electro-oculogram, demonstrating excellent performances for the detection of biosignals from delicate body parts, such as the face, thus demonstrating the effectiveness of the approach for the development of a new generation of magnetically connectable epidermal electrodes for critical biopotentials monitoring
Control architecture to provide E2E security in interconnected systems: the (new) SHIELD approach
Modern Systems are usually obtained as incremental composition of proper (smaller and SMART) subsystems interacting through communication interfaces. Such flexible architecture allows the pervasive provisioning of a wide class of services, ranging from multimedia contents delivery, through monitoring data collection, to command and control functionalities. All these services requires that the adequate level of robustness and security is assured at End-to- End (E2E) level, according to user requirements that may vary depending on the specific context or the involved technologies. A flexible methodology to dynamically control the security level of the service being offered is then needed. In this perspective, the authors propose an innovative control architecture able to assure E2E security potentially in any application, by dynamically adapting to the underlying systems and using its resources to “build the security”. In particular, the main novelties of this solution are: i) the possibility of dynamically discovering and composing the available functionalities offered by the environment to satisfy the security needs and ii) the possibility of modelling and measuring the security through innovative technology-independent metrics. The results presented in this paper moves from the solutions identified in the pSHIELD project and enrich them with the innovative advances achieved through the nSHIELD research, still ongoing. Both projects have been funded by ARTEMIS-JU
Segmental Liver Transplantation From Living Donors Report of the Technique and Preliminary Results in Dogs
A technique of orthotopic liver transplantation using a segmental graft from living donors was
developed in the dog. Male mongrel dogs weighing 25–30 kg were used as donors and 10–15 kg as
recipients. The donor operation consists of harvesting the left lobe of the liver (left medial and left
lateral segments) with the left branches of the portal vein, hepatic artery and bile duct, and the left
hepatic vein. The grafts are perfused in situ through the left portal branch to prevent warm ischemia.
The recipient operation consists of two phases: 1total hepatectomy with preservation of the inferior
vena cava using total vascular exclusion of the liver and veno-venous bypass, 2implantation of the graft
in the orthotopic position with anastomosis of the left hepatic vein to the inferior vena cava and portal,
arterial and biliary reconstruction. Preliminary experiments consisted of four autologous left lobe
transplants and nine non survival allogenic left lobe transplants. Ten survival experiments were
conducted. There were no intraoperative deaths in the donors and none required transfusions. One
donor died of sepsis, but all the other donor dogs survived without complication. Among the 10 grafts
harvested, one was not used because of insufficient bile duct and artery. Two recipients died
intraoperatively of air embolus and cardiac arrest at the time of reperfusion. Three dogs survived, two
for 24 hours and one for 48 hours. They were awake and alert a few hours after surgery, but eventually
died of pulmonary edema in 2 cases and of an unknown reason in the other. Four dogs died 2–12 hours
postoperatively as a result of hemorrhage for the graft's transected surface. An outflow block after
reperfusion was deemed to be the cause of hemorrhage in these cases. On histologic examination of the
grafts, there were no signs of ischemic necrosis or preservation damage
A Case-Control Comparison of Surgical and Functional Outcomes of Robotic-Assisted Spleen-Preserving Left Side Pancreatectomy versus Pure Laparoscopy
Aim During left-sided spleen-preserving pancreatectomy (SPLP), limitations of laparoscopy may require spleen sacrifice or conversion to maintain patient safety. The objective of our study is to compare surgical and functional outcomes of robot-assisted and pure laparoscopic SPLP in patients with benign or borderline lesions of the body/tail of the pancreas. Patients and methods This was a case-matched study: fifteen patients who had robotic SPLP (R-SPLP) were matched with 15 comparable patients who had pure laparoscopic SPLP (L-SPLP). The peri-operative variables (conversion rate, amount of bleeding, operation time, length of hospital stay, complications, mortality and readmission) as well as the spleen preservation rate were compared between the two groups, The European Organisation for Research and Treatment of Cancer QLQ-C30 (EORTC QLQ-C30) specific questionnaires were used in each arm after at least 1 year of follow up in order to evaluate quality of life (QoL). Results No R-SPLP was converted to conventional laparoscopy, hand-assisted laparoscopy, or open surgery whereas L-SPLP had a conversion rate of 13.3% (p=n.s.); also fistula formation (20% vs. 46%; p=n.s.) was higher in the laparoscopic group although not statistically significant. Mean operative time (220 vs. 279 min; p=0.027) was shorter and the spleen-preserving rate (fail/ success, 0/15 vs. 4/11; p=0.03) of R-SPLP was significantly better compared to L-SPLP. Moreover, length of hospital stay was significantly shorter in the R-SPLP group compared to the L-SPLP group (6.5 vs. 8.8 days; p=0.04). Post-operative high grade surgical complications occurred only in one L-SPLP patient (0% vs. 6.6%; p=n.s.). Quality of life scores were not significantly different between the two groups. Conclusions R-SPLP could provide an increased chance for spleen preservation and faster surgical procedure. Furthermore, fistula formation and conversion rate seem to be lower, reducing the length of the hospital stay. Our case matched study confirmed the potential peri-operative benefits of robotic assistance in this setting, however these benefits did not translate into a better quality of life at least one year post-operatively
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