Conformational ensembles of an RNA hairpin using molecular dynamics and sparse NMR data

Solution nuclear magnetic resonance (NMR) experiments allow RNA dynamics to be determined in an aqueous environment. However, when a limited number of peaks are assigned, it is difficult to obtain structural information. We here show a protocol based on the combination of experimental data (Nuclear Overhauser Effect, NOE) and molecular dynamics simulations with enhanced sampling methods. This protocol allows to (a) obtain a maximum entropy ensemble compatible with NMR restraints and (b) obtain a minimal set of metastable conformations compatible with the experimental data (maximum parsimony). The method is applied to a hairpin of 29 nt from an inverted SINEB2, which is part of the SINEUP family and has been shown to enhance protein translation. A clustering procedure is introduced where the annotation of base-base interactions and glycosidic bond angles is used as a metric. By reweighting the contributions of the clusters, minimal sets of four conformations could be found which are compatible with the experimental data. A motif search on the structural database showed that some identified low-population states are present in experimental structures of other RNA transcripts. The introduced method can be applied to characterize RNA dynamics in systems where a limited amount of NMR information is available

Automatic Scheduling for a Ground Segment as a Service Platform Dedicated to Small Satellites

Together with the development of nano, micro, and small satellite missions and constellations, the necessity for efficient and tailored ground segments is raising. The peculiarities of the market together with the technological developments of the recent years have led to the idea of ground segment as a service. To meet these needs Leaf Space introduced Leaf Line. An essential part of such service consists of scheduling contact windows over the worldwide-deployed network of ground stations. This is an NP-hard problem, which is often solved with methods belonging to the class of operational research. Generally, the orbits of small satellites are very low, characterized by short-timed contact windows. This condition leads to needs way different from those associated to long-lived high-orbit satellites, which most of the literature on scheduling algorithms for telecommunication systems is focused on. Furthermore, a service dedicated to SMEs and NewSpace startups brings additional challenges linked to customer needs. These peculiarities require the development of new, tailored, scheduling algorithms. In the proposed strategy it is assumed to have no information about the state of the satellite (stored data and available energy), and that start and end of contact windows are fixed. In this work, the scheduling is treated as a highly constrained combinatorial optimization problem; various approaches are described and then compared. Such algorithms are iterative, and they all leverage the structure of the problem; specifically, many efforts are made to appropriately reduce the search space. Although optimality cannot be guaranteed, good solutions that are reasonably close to optimal can be obtained. It is found that depending on the problem settings, different algorithms can stand out as the best ones. This paper presents the work done on the scheduling library that is currently powering the Leaf Line network: this platform is offering an easy-to-use, cloud-based and high-availability ground segment service for small satellites operators

Wound healing dynamics, morbidity, and complications of palatal soft-tissue harvesting

Palatal-tissue harvesting is a routinely performed procedure in periodontal and peri-implant plastic surgery. Over the years, several surgical approaches have been attempted with the aim of obtaining autogenous soft-tissue grafts while minimizing patient morbidity, which is considered the most common drawback of palatal harvesting. At the same time, treatment errors during the procedure may increase not only postoperative discomfort or pain but also the risk of developing other complications, such as injury to the greater palatine artery, prolonged bleeding, wound/flap sloughing, necrosis, infection, and inadequate graft size or quality. This chapter described treatment errors and complications of palatal harvesting techniques, together with approaches for reducing patient morbidity and accelerating donor site wound healing. The role of biologic agents, photobiomodulation therapy, local and systemic factors, and genes implicated in palatal wound healing are also discussed

The Effect of Keratinized Mucosa on Peri-Implant Health and Patient-Reported Outcome Measures: A Systematic Review and Meta-Analysis

Objectives: The aim of this systematic review was to analyze the effect of keratinized mucosa (KM) on different peri-implant health-related parameters and on patient-reported outcome measures (PROMs). Material and methods: Randomized controlled trials, cohort, cross-sectional and case-control human studies with a follow-up period of at least 6 months comparing two groups of patients with presence or absence of KM, or with KM < 2 mm or & GE;2 mm were included. Primary outcomes were implant failures, PROMs and BoP (BoP/mBI). Additional outcomes were PPD, plaque accumulation (mPI/PI), gingival inflammation (GI/mGI), marginal bone loss (MBL), soft tissue recession (REC) and biological complications. Results: Fifteen studies were included (one RCT, two cohort prospective and twelve cross-sectional). Meta-analysis was performed for cross-sectional studies. Implant failure and complications were not presented as outcome measures, and five studies analyzed PROMs. Results from the meta-analysis reported no evidence of any statistical significant difference between groups in PPD, BoP and MBL, while a statistical significant difference in GI/BI, PI and REC was present in favor of the group with KW & GE; 2 mm. More biological complications were present in the group with no KM/KM < 2 mm but few cases were present to draw any conclusions. Although a meta-analysis could not be performed, a consistent trend toward the worst pain/discomfort in KM < 2 mm was observed. Conclusions: No clear evidence was found supporting the role of KM in peri-implant health and PROMs, even if more plaque and marginal inflammation were present in the KM < 2 mm group. Clinical relevance: KM could have a role in patients with erratic maintenance and patient comfort

Facial implant gingival level and thickness changes following maxillary anterior immediate tooth replacement with scarf-connective tissue graft: A 4-13-year retrospective study

ObjectiveA scarf-shaped connective tissue graft can be placed at the facial and proximal aspect of the peri-implant soft tissue zone during immediate implant placement and provisionalization (IIPP) procedures in the esthetic zone to optimize implant esthetics without the need of flap reflection. This retrospective study evaluated soft tissue stability after scarf-connective tissue graft (S-CTG) in conjunction with IIPP procedures in the esthetic zone. Materials and MethodsPatients who received IIPP with S-CTG with a minimum 1-year follow-up were evaluated. Mid-facial gingival level (MFGL) change and mid-facial gingival thickness (MFGT) change were measured and compared at the pre-op (T0), IIPP + S-CTG surgery (T1), follow up appointment with MFGT measurement (T2), and latest follow-up appointment (T3). Implant success rate and graft necrosis were also recorded. ResultsA total of 22 IIPP and S-CTG procedures in 20 patients were evaluated in the study. After a mean follow-up of 8.2 years (3.9-13.4) (T3), all implants remained osseointegrated (22/22 [100%]), with statistically insignificant mean midfacial gingival level change of -0.19 mm (-1.5 to 0.8). Statistically significant difference in midfacial gingival thickness (MFGT) was noted (2.5 mm [1.8-3.5 mm]) after a mean follow-up time (T2) of 2.3 years (1-8.6) when compared with MFGT at baseline (1.1 mm [0.6-1.3 mm]) (T1). Necrosis of S-CTG during initial healing phase was noted in 9% (2/22) of the sites. ConclusionsWithin the confines of this study, scarf-connective tissue graft at time of immediate implant placement and provisionalization can thicken the gingiva and maintain the gingival level at the critical soft tissue zone. Clinical SignificanceManaging the soft tissue zone is as important as that of the hard tissue zone for peri-implant esthetics. Connective tissue graft is one of the methods that can enhance the final esthetic outcomes. This retrospective study has demonstrated that Scarf-CTG technique is an effective treatment modality to maintain soft tissue stability

The influence of tooth location on the outcomes of multiple adjacent gingival recessions treated with coronally advanced flap: A multicenter reâ analysis study

BackgroundTooth location has been shown to play a significant role on root coverage outcomes. However, whether this has an impact on the outcomes of coronally advanced flap (CAF) for treating multiple adjacent gingival recessions (MAGRs) remains to be determined. The aim of this study was to investigate the impact of tooth location, flap design, and flap extension on the outcomes of MAGRs following CAF with or without a connective tissue graft (CTG).MethodsA reâ analysis of six previously published clinical trials evaluating the outcomes of CAF in the treatment of MAGRs was performed using mixed regression and logistics to assess the influence of potentially influential factors on the treatment outcomes.ResultsSix hundred and nine MAGRs in 166 patients were evaluated. The anterior maxilla (second sextant) was associated to the highest mean root coverage (mRC) and complete root coverage (CRC) outcome (P  0.05). Lastly, teeth in the distal part of the flap showed lower mRC and CRC than teeth in the central or mesial position (P < 0.05).ConclusionsTooth location was found to play a key role in determining the amount of root coverage achievable, with maxillary canines and incisors being associated with the highest outcomes compared with other sextants. Maxillary MAGRs showed greater mRC and CRC than mandibular MAGRs.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153060/1/jper10366_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153060/2/jper10366.pd

Extracellular matrixâ based scaffolding technologies for periodontal and periâ implant soft tissue regeneration

The present article focuses on the properties and indications of scaffoldâ based extracellular matrix (ECM) technologies as alternatives to autogenous soft tissue grafts for periodontal and periâ implant plastic surgical reconstruction. The different processing methods for the creation of cellâ free constructs resulting in preservation of the extracellular matrices influence the characteristics and behavior of scaffolding biomaterials. The aim of this review is to discuss the properties, clinical application, and limitations of ECMâ based scaffold technologies in periodontal and periâ implant soft tissue augmentation when used as alternatives to autogenous soft tissue grafts.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153617/1/jper10427.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153617/2/jper10427_am.pd

Autogenous soft tissue grafting for periodontal and periâ implant plastic surgical reconstruction

This stateâ ofâ theâ art review presents the latest evidence and the current status of autogenous soft tissue grafting for soft tissue augmentation and recession coverage at teeth and dental implant sites. The indications and predictability of the free gingival graft and connective tissue graft (CTG) techniques are highlighted, together with their expected clinical and esthetic outcomes. CTGs can be harvested from the maxillary tuberosity or from palate with different approaches that can have an impact on graft quality and patient morbidity. The influence of CTGs on soft tissue thickness and keratinized tissue width are also discussed.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153773/1/jper10428_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153773/2/jper10428.pd

Living cellâ based regenerative medicine technologies for periodontal soft tissue augmentation

The cultivation of human living cells into scaffolding matrices has progressively gained popularity in the field of periodontal wound healing and regeneration. Living cellular constructs based on fibroblasts, keratinocytes alone or in combination have been developed and used as alternatives to autogenous soft tissue grafts in keratinized tissue augmentation and in root coverage procedures. Their promising advantages include reduced patient morbidity, unlimited graft availability, and comparable esthetics. This manuscript reviews soft tissue augmentation and root coverage procedures using bioengineered living cellular therapy and highlights their expected clinical, esthetic, and patientâ related outcomes.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154237/1/jper10429.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154237/2/jper10429_am.pd

Biologicsâ based regenerative technologies for periodontal soft tissue engineering

This manuscript provides a stateâ ofâ theâ art review on the efficacy of biologics in root coverage procedures, including enamel matrix derivative, plateletâ derived growth factor, platelet concentrates, and fibroblastâ growth factorâ 2. The mechanism of action and the rationale for using biologics in periodontal plastic surgery, as well as their anticipated benefits when compared with conventional approaches are discussed. Although the clinical significance is still under investigation, preclinical data and histologic evidence demonstrate that biologicâ based techniques are able to promote periodontal regeneration coupled with the provision of tooth root coverage.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154295/1/jper10426_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154295/2/jper10426.pd