60 research outputs found
A low complexity resource allocation algorithm for multicast service delivery in OFDMA networks
Allocating and managing radio resources to multicast transmissions in Orthogonal Frequency-Division Multiple Access (OFDMA) systems is the challenging research issue addressed by this paper. A subgrouping technique, which divides the subscribers into subgroups according to the experienced channel quality, is considered to overcome the throughput limitations of conventional multicast data delivery schemes. A low complexity algorithm, designed to work with different resource allocation strategies, is also proposed to reduce the computational complexity of the subgroup formation problem. Simulation results, carried out by considering the Long Term Evolution (LTE) system based on OFDMA, testify the effectiveness of the proposed solution, which achieves a near-optimal performance with a limited computational load for the system
Using a distributed Shapley-value based approach to ensure navigability in a social network of smart objects
The huge number of nodes that is expected to join
the Internet of Things in the short term will add major scalability
issues to several procedures. A recent promising approach to
these issues is based on social networking solutions to allow
objects to autonomously establish social relationships. Every
object in the resulting Social IoT (SIoT) exchanges data with
its friend objects in a distributed manner to avoid the need
for centralized solutions to implement major functionalities,
such as: node discovery, information search and trustworthiness
management. However, the number and types of established
friendship affects network navigability. This paper addresses this
issue proposing an efficient, distributed and dynamic strategy for
the objects to select the right friends for the benefit of the overall
network connectivity. The proposed friendship selection model
relies on a Shapley-value based algorithm mapping the friendship
selection process in the SIoT onto the coalition formation problem
in a corresponding cooperative game. The obtained results show
that the proposed solution is able to ensure global navigability,
measured in terms of average path length among two nodes in
the network, by means of a distributed and wise selection of the
number of friend objects a node has to handle
Persistent systemic microbial translocation, inflammation, and intestinal damage during Clostridioides difficile infection
Background. Clostridioides difficile infection (CDI) might be complicated by the development of nosocomial bloodstream infection (n-BSI). Based on the hypothesis that alteration of the normal gut integrity is present during CDI, we evaluated markers of microbial translocation, inflammation, and intestinal damage in patients with CDI. Methods. Patients with documented CDI were enrolled in the study. For each subject, plasma samples were collected at T0 and T1 (before and after CDI therapy, respectively), and the following markers were evaluated: lipopolysaccharide-binding protein (LPB), EndoCab IgM, interleukin-6, intestinal fatty acid binding protein (I-FABP). Samples from nonhospitalized healthy controls were also included. The study population was divided into BSI+/BSI- and fecal microbiota transplantation (FMT) +/FMT- groups, according to the development of n-BSI and the receipt of FMT, respectively. Results. Overall, 45 subjects were included; 8 (17.7%) developed primary n-BSI. Markers of microbial translocation and intestinal damage significantly decreased between T0 and T1, however, without reaching values similar to controls (P < .0001). Compared with BSI-, a persistent high level of microbial translocation in the BSI+ group was observed. In the FMT+ group, markers of microbial translocation and inflammation at T1 tended to reach control values. Conclusions. CDI is associated with high levels of microbial translocation, inflammation, and intestinal damage, which are still present at clinical resolution of CDI. The role of residual mucosal perturbation and persistence of intestinal cell damage in the development of n-BSI following CDI, as well as the possible effect of FMT in the restoration of mucosal integrity, should be further investigated
Early Warning Systems for Emerging Profiles of Antimicrobial Resistance in Italy: A National Survey
Antimicrobial resistance (AMR) national surveillance systems in Italy lack alert systems for timely detection of emerging profiles of AMR with potential relevance to public health. Furthermore, the existence of early warning systems (EWS) at subnational level is unclear. This study aims at mapping and characterizing EWS for microbiological threats available at regional level in Italy, focusing on emerging AMR, and at outlining potential barriers and facilitators to their development/implementation. To this end, a three-section, web-based survey was developed and administered to all Italian regional AMR representatives from June to August 2022. Twenty out of twenty-one regions and autonomous provinces (95.2%) responded to the survey. Among these, nine (45%) reported the implementation of EWS for microbiological threats at regional level, three (15%) reported that EWS are in the process of being developed, and eight (40%) reported that EWS are not currently available. EWS characteristics varied widely among the identified systems concerning both AMR profiles reported and data flow: the microorganisms most frequently included were extensively drug-resistant (XDR) Enterobacterales, with the lack of a dedicated regional IT platform reported in most cases. The results of this study depict a highly heterogeneous scenario and suggest that more efforts aimed at strengthening national AMR surveillance systems are needed
Does immediate breast reconstruction after mastectomy and neoadjuvant chemotherapy influence the outcome of patients with non-endocrine responsive breast cancer?
Background/Aim: In breast cancer (BC) patients, breast surgery followed by immediate breast reconstruction (IBR) might favour recurrences and metastases due to extensive surgical manipulation. We retrospectively investigated whether IBR after mastectomy and neoadjuvant chemotherapy (NT) influenced the outcome in patients with early and locally advanced oestrogen receptor (ER)-negative BC. Patients and Methods: Between 1995 and 2006, 133 BC patients received NT followed by total mastectomy, 59 of whom underwent IBR. Patients receiving IBR (IBR group) were compared to patients who did not receive IBR (no-IBR group) over a prolonged median follow-up time (8.2 years). Results: Patients receiving IBR were on average younger than patients not receiving IBR (p<0.00I). The percentage of patients with positive clinical nodal status (cN) was 19% in the IBR group and 7% in no-IBR group (p=0.036), whereas patients without 1BR were more frequently diagnosed as clinical T4 (59% vs. 15%, p<0.001). The 5-year cumulative incidence of locoregional recurrences were 14% in the no-IBR group and 21% in the IBR group. The hazard of locoregional events, adjusted for age, clinical T and cN, was significantly greater in the IBR group than in the no-IBR group (hazard ratio (HR)=2.77, p=0.045). The 5-year cumulative incidences of distant metastases were similar in the two groups (p=0.414). Conclusion: IBR following total mastectomy in patients with ER-negative disease after NT is associated with a worse rate of local relapses. More insight in mechanisms of wound healing and extent of surgery is required to further investigate this observation
Extracranial association of arteriovenous and venous malformations. Case report
Association of multiple vascular malformations of the face is a rare condition. An arteriovenous malformation (AVM) with a venous malformation as the draining vein is also a rarity. We report a case of extracranial mixed vascular malformations that deformed the normal architecture of the lower face. Removal of the AVM was followed by stability of the jaw and tongue malformation, indicating the AVM used the venous malformation as its draining vein. This approach spared the patient severe cosmetic and functional sequela
The distally based sural neurocutaneous flap in reconstruction of lower limb: our experience
Our study concerns eight patients who have undergone surgery at the Department of Plastic, Reconstructive and Aesthetic Surgery of the University of Perugia, for the reconstruction of lower limb using the distally based sural neurocutaneous flap for covering loss of substance of various origin, from October 2007 to November 2009. The aim of our study is to demonstrate the reliability of distally based neurocutaneous sural flap in reconstruction of lower limb following a loss of substance of different nature involving the lower third of the leg. Eight patients were on systemic and local clinical conditions that can not be undergoing surgery with use of free flap. In five patients (62%) the loss of substance had been caused by traffic accident while another patient (12%) had been the victim of an accident at work. Two patients (26%) had suffered from pressure ulcers and were unstable with regard to the vascularisation. We observed no cases of total necrosis of the flap and in all eight patients we showed good healing. Follow up was 2, 4, 6, and 9 months after surgical intervention. Our study has shown that the use of the distally based sural neurocutaneous flap in reconstruction of lower limbs, as a salvage procedure, is still a valid alternative procedure to free tissue transfer. Because of reduced operative times, reduced anaesthetic risk, reduced risk of total flap necrosis and reduced costs, it could be considered as a preferable choice in selected cases
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