1,721,287 research outputs found
Current molecular, cellular and genetic aspects of Peri-Implantitis Disease: A narrative review
Full text link(1) Background: Peri-implantitis is a multi-factorial disease with an inflammatory background that occurs in both soft and hard tissues surrounding implants. In recent years, the understanding of the cellular, molecular and genetic background of peri-implantitis has broadened. This study aims to summarize the currently available articles on the subject and highlight the most recent advances over the last 20 years. (2) Methods: For this study, the Embase and PubMed libraries were searched using the keywords: (“peri-implantitis” AND “cytokine” OR “genetics” OR “cellular”) and (“peri-implantitis” AND “cytokine” OR “genetics” OR “cellular” AND “risk factors”). The search revealed a total of 3013 articles (992 from PubMed, 2021 from Embase). Following screening of the titles and abstracts and full-text reads, 55 articles were included. (3) Results: In peri-implantitis IL-6, IL-1β, TNF-α, MMP-8 and their genetic variations appear to be the most important cytokines in relation to not only pathogenesis, but also their potential diagnostic capabilities. Epithelial and inflammatory cells, along with those of the bone lineage, are prime cellular elements found in peri-implantitis. (4) Conclusions: A wide array of cells stand behind peri-implantitis, as well as cytokines and their genetic variations that take part in the process. However, the growing interest in this topic has led to the introduction of specific new diagnostic tools to enable a better understanding of patients’ responses to treatment and, in turn, to even enable prediction of the risk of developing peri-implant disease
Semi-global Fixed-time State Estimation and unknown Input Reconstruction via First-order Sliding Mode observers with Delay
Full text linkThis paper addresses the state estimation and unknown input reconstruction in strongly observable linear systems under the so-called matching conditions. Our proposal extends previous approaches to predefined-time state estimation, which involved the use of a pair of time-delay observers, adapting them to the framework of sliding mode observation in the presence of unknown inputs. As a result, a novel sliding mode-based observation algorithm is developed, which exhibits desirable properties such as global finite-time convergence or semi-global fixed-time convergence. Notably, the method is also capable of reconstructing the unknown inputs without requiring any low-pass filtering or continuous approximations of the discontinuous observer signals. The convergence properties are proven through a formal stability analysis and validated through numerical simulations
Root coverage with a coronally positioned flap used in combination with enamel matrix derivative: 18-month clinical evaluation.
No full textAbstract
BACKGROUND:
Ginigival recession can be successfully treated with coronally positioned flaps. Twelve-month data failed to demonstrate that topical application of enamel matrix derivative (EMD) used in combination with the coronally positioned flap enhances clinical outcomes of the surgical technique used alone. This study was designed to examine the effects of EMD combined with the coronally positioned flap over an 18-month postoperative period.
METHODS:
Thirty patients presenting with Miller Class I or II gingival recessions on single-rooted teeth participated in this parallel-design clinical study. Six weeks after phase I therapy, recession areas were surgically treated with a coronally positioned flap for root coverage. Teeth in the experimental group received EMD treatment of the exposed root, whereas control teeth did not. Clinical parameters evaluated at baseline and 18 months postoperatively included gingival recession, clinical attachment level, probing depth, and the apico-coronal dimension of the keratinized tissue.
RESULTS:
Compared to baseline, 18-month measurements showed a significant reduction in probing depth, gain in attachment level, and decrease in gingival recession for control and experimental groups. When the results of the two treatment groups were compared, the experimental group presented with significantly greater root coverage than the control group (2.66 +/- 0.61 mm versus 1.73 +/- 0.70 mm, respectively), more gain in clinical attachment than the control group (2.80 +/- 0.76 mm versus 2.06 +/- 0.70 mm, respectively), and a greater gain in the apico-coronal dimension of the keratinized tissue than the control group (0.13 +/- 0.06 mm versus -0.06 +/- 0.01 mm, respectively).
CONCLUSION:
The results of this study indicate that topical application of EMD is beneficial in augmenting the effects of the coronally positioned flap in terms of amount of root coverage, gain in clinical attachment, and in increasing the apico-coronal dimension of the keratinized tissue
A novel finite-time first-order sliding-mode unknown input observer with certain fixed-time convergence characteristics
No full textFor uncertain linear system subjected to uniformly bounded unknown inputs it is presented a novel finite-time unknown input first-order sliding-mode observer. The strategy involves the design of a pair of quadratically stable first-order sliding-mode observers, aimed to guarantee the robustness to non-smooth unknown inputs and the finite-time convergence to zero of the output estimation errors. Then, the exact estimation of the unmeasured states is achieved in a fixed-time since the sliding motion is established through the design of an auxiliary output consisting of a delayed linear-combination of the estimations provided by the above-mentioned pair of observers. To confirm the effectiveness of the proposed scheme, along with a sketch of the proof of its convergence characteristics, a detailed numerical comparison analysis with the existing first-order sliding-mode competitor observers is illustrated
Multi-Agent Coordination of Thermostatically Controlled Loads by Smart Power Sockets for Electric Demand Side Management
No full textThis article presents a multi-agent control architecture and an online optimization method based on a dynamic average consensus to coordinate the power consumption of a large population of thermostatically controlled loads (TCLs). Our objective is to penalize peaks of power demand, smooth the load profile, and enable demand-side management. The proposed architecture and methods exploit only local measurements of power consumption via smart power sockets (SPSs) with no access to their internal temperature. No centralized aggregator of information is exploited, and agents preserve their privacy by cooperating anonymously only through consensus-based distributed estimation. The interactions among devices occur through an unstructured peer-to-peer (P2P) network over the Internet. Methods for parameter identification, state estimation, and mixed logical modeling of TCLs and SPSs are included. The architecture is designed from a multi-agent and plug-and-play perspective, in which existing household appliances can interact with each other in an urban environment. Finally, a novel low-cost testbed is proposed along with numerical tests and experimental validation
A Heuristic approach for Online Distributed Optimization of Multi-Agent Networks of Smart Sockets and Thermostatically Controlled Loads based on Dynamic Average Consensus
No full textThis paper presents a novel heuristic online optimization method and multi-agent control architecture to optimize the Peak-to-Average power Ratio (PAR) of a large population of Thermostatically Controlled Loads (TCLs) over a sliding receding horizon time window. The proposed architecture exploits only local measurements of the TCL power consumption with no knowledge of their internal temperature. No centralized aggregator of information is used and agents preserve their privacy by cooperating only through consensus-based distributed estimation. TCLs interactions occur via Smart Power Sockets (SPSs) which are interconnected through a peer-to-peer (P2P) network over the internet. The control architecture is designed from a multi-agent perspective in which real household appliances can interact with each other via SPSs.Our contribution is twofold: first we introduce a novel hybrid modelling of the TCL-plus-SPS system along with a method for parameter identification and a method estimate the internal state of the TLC through SPS performed power measurements; then we provide a heuristic algorithm for online distributed optimization of the on/off states of the SPSs which exploits a dynamic average consensus algorithm to estimate the planned future average power consumption of the network while preserving the agents' privacy. Numerical simulations and preliminary experimental results performed in a novel low cost testbed are provided
Surgical treatment of a cemental tear-associated bony defect using hyaluronic acid and a resorbable collagen membrane: a 2-year follow-up
Full text linkIntroduction A cemental tear (CeT) is a special type of surface root fracture that may cause periodontal and even periapical tissue destruction. Unfortunately, there is limited knowledge as to how these rare cases can effectively be treated. The present case is believed to be the first reported in the literature treating a bony defect caused by a cemental tear with hyaluronic acid (HA) and a collagen membrane. The aim of this case report is to present a regenerative surgical approach with clinical and tomographic success and stability at 2-year follow-up.Case PresentationA 61-year-old patient presented with spontaneous pain and gingival swelling over his right central maxillary incisor. Radiographically, a radiolucent area was observed in the medial third between both central incisors. The tomographic evaluation showed a buccal bone dehiscence and a bony defect. Once the differential diagnosis with an endodontic-periodontal lesion and root fracture was performed, CeT was the presumptive diagnosis. During the exploratory flap surgery, a small root fragment (CeT) on the mesial side of the tooth was founded and removed. The bony lesion was treated with hyaluronic acid (HA) and a resorbable collagen membrane. At 2-year follow-up clinical, radiographic, and tomographic success was observed.ConclusionA CeT-associated bony defect could be successfully treated after removing cemental fragments and performing a regenerative approach using HA and a resorbable collagen membrane
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A Sliding Mode Observer design for the Average State Estimation in Large-Scale Systems
Full text linkIn this letter the average state estimation problem on a large-scale system with only few gateway nodes available for measurements is solved as the design problem of a reduced-order sliding mode observer subjected to unmatched perturbations. Necessary and sufficient conditions to guarantee the exact estimation are derived. Still, even in the case such conditions are not fulfilled, the boundedness of the estimation error is proved. Finally, a criteria to minimize such bound, and a gain adaptation law to trade-off that bound and its convergence rate are provided. Neither the observer complexity nor the estimation error depend explicitly on the size of the system, thus making the approach scalable and computationally tractable. Simulations supporting the effectiveness of the proposed strategy and a comparison with other existing strategies are also provided
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