4,841 research outputs found
Synchronization of dynamical hypernetworks: dimensionality reduction through simultaneous block-diagonalization of matrices
We present a general framework to study stability of the synchronous solution
for a hypernetwork of coupled dynamical systems. We are able to reduce the
dimensionality of the problem by using simultaneous block-diagonalization of
matrices. We obtain necessary and sufficient conditions for stability of the
synchronous solution in terms of a set of lower-dimensional problems and test
the predictions of our low-dimensional analysis through numerical simulations.
Under certain conditions, this technique may yield a substantial reduction of
the dimensionality of the problem. For example, for a class of dynamical
hypernetworks analyzed in the paper, we discover that arbitrarily large
networks can be reduced to a collection of subsystems of dimensionality no more
than 2. We apply our reduction techique to a number of different examples,
including a class of undirected unweighted hypermotifs of three nodes.Comment: 9 pages, 6 figures, accepted for publication in Phys. Rev.
CAD/CAM Diagnostic Esthetic Functional Splint (DEFS) as a removable prototype to evaluate the final prosthetic rehabilitation: a narrative review.
The main objective of this narrative review was to provide an overview of DEFS (Diagnostic Esthetic Functional Splint), namely CAD/CAM manufactured, âsnap-retainedâ, tooth-colored splints available by materials exhibiting a certain degree of elasticity (like polycarbonates or acetal resins) for restoring function, esthetics and occlusion in several clinical situations, before or as an intermediate alternative to undergoing the final treatment. The search strategy included all papers dealing with snap-retained prosthetic systems and was based on a literature review of papers available in electronic databases (Pubmed/Medline, Evidence-Based Dentistry, BMJ Evidence-Based Medicine, Dynamed, Embase, BMJ Clinical Evidence, Web of Science, Scientific reports); eligible papers were researched on Opengreyand a manual search was performed, as well. From the electronic databases emerged 13,199 records, many of which were duplicates. The grey literature and the manual research did not produce any eligible article. After duplicates removal, 7690 records were obtained. Titles, abstracts and keywords were analyzed. The studies concerning the topic of interest were examined by the reviewers and discussed. Although no evidence-based data were found in the literature, according to the authorsâ clinical experience, the DEFS (Diagnostic Esthetic Functional Splint) is a very promising solution in multiple clinical situations, due to its diagnostic, therapeutical, functional and esthetic versatility
Cooling of Sr to high phase-space density by laser and sympathetic cooling in isotopic mixtures
Based on an experimental study of two-body and three-body collisions in
ultracold strontium samples, a novel optical-sympathetic cooling method in
isotopic mixtures is demonstrated. Without evaporative cooling, a phase-space
density of is obtained with a high spatial density that should
allow to overcome the difficulties encountered so far to reach quantum
degeneracy for Sr atoms.Comment: 5 pages, 4 figure
An allelic variant in the intergenic region between ERAP1 and ERAP2 correlates with an inverse expression of the two genes
The Endoplasmatic Reticulum Aminopeptidases ERAP1 and ERAP2 are implicated in a variety of immune and non-immune functions. Most studies however have focused on their role in shaping the HLA class I peptidome by trimming peptides to the optimal size. Genome Wide Association Studies highlighted non-synonymous polymorphisms in their coding regions as associated with several immune mediated diseases. The two genes lie contiguous and oppositely oriented on the 5q15 chromosomal region. Very little is known about the transcriptional regulation and the quantitative variations of these enzymes. Here, we correlated the level of transcripts and proteins of the two aminopeptidases in B-lymphoblastoid cell lines from 44 donors harbouring allelic variants in the intergenic region between ERAP1 and ERAP2. We found that the presence of a G instead of an A at SNP rs75862629 in the ERAP2 gene promoter strongly influences the expression of the two ERAPs with a down-modulation of ERAP2 coupled with a significant higher expression of ERAP1. We therefore show here for the first time a coordinated quantitative regulation of the two ERAP genes, which can be relevant for the setting of specific therapeutic approaches
âDigitally Oriented Materialsâ: Focus on Lithium Disilicate Ceramics
The present paper was aimed at reporting the state of the art about lithium disilicate ceramics. The physical, mechanical, and optical properties of this material were reviewed as well as the manufacturing processes, the results of in vitro and in vivo investigations related to survival and success rates over time, and hints for the clinical indications in the light of the latest literature data. Due to excellent optical properties, high mechanical resistance, restorative versatility, and different manufacturing techniques, lithium disilicate can be considered to date one of the most promising dental materials in Digital Dentistry
Area accuracy gradient and artificial markers: a three-dimensional analysis of the accuracy of IOS scans on the completely edentulous upper jaw
Aim The present paper aimed to assess the accuracy gradient of scans made using an intraoral scanner (IOS) on a totally edentulous maxilla and the effectiveness of artificial markers. Materials and methods A reference scan was made by scanning a fully edentulous upper jaw cast (RC) with a dedicated metrological machine. On the RC, an IOS was used to make 10 scans then superimposed to detect their area accuracy gradient. Artificial markers with a diameter of 2 mm were placed in the less accurate areas following two approaches. In the first one, semispherical resin composite markers were used. In the second approach, a dermographic pen was used to draw circular flat markers. Three experimental groups (n = 10) were obtained: âno markersâ for the control group without markers, âembossed markersâ for resin composite markers, and âflat markersâ for ink-drawn ones. The scans were processed into a specialized software, where trueness and precision were measured in millimeters. Descriptive statistics (95% C.I.) were conducted, also, the Games-Howell and Kruskal-Wallis tests (α = .05) were used to investigate differences between groups.
Results Mean values for trueness were: no markers 48.8 (39.2- 58.3); embossed markers 39.2 (37.5-40.8); flat markers 60.5 (47.7-73.4), with statistically significant differences between embossed and flat markers (p = .011). Mean values for precision were: no markers 46.7 (29.7-63.7); embossed markers 41.4 (34.7- 48); flat markers 99.8 (69.3-130.3), with significant differences between embossed markers and flat ones (p = .008) and between the latter and the control group (p = .005). Minor accuracy was detected at both tuberosities, palate, posterior aspect of the papilla, and flattened areas of the ridges. Conclusions To improve IOS scans accuracy on the totally edentulous upper jaw, it is suggested to place embossed markers, rather than flat ones, in the areas of minor accuracy
Steps towards a map of the nearby universe
We present a new analysis of the Sloan Digital Sky Survey data aimed at
producing a detailed map of the nearby (z < 0.5) universe. Using neural
networks trained on the available spectroscopic base of knowledge we derived
distance estimates for about 30 million galaxies distributed over ca. 8,000 sq.
deg. We also used unsupervised clustering tools developed in the framework of
the VO-Tech project, to investigate the possibility to understand the nature of
each object present in the field and, in particular, to produce a list of
candidate AGNs and QSOs.Comment: 3 pages, 1 figure. To appear in Nucl Phys. B, in the proceedings of
the NOW-2006 (Neutrino Oscillation Workshop - 2006), R. Fogli et al. ed
Mutations in proteins involved in E-C coupling and SOCE and congenital myopathies
In skeletal muscle, Ca2+ necessary for muscle contraction is stored and released from the sarcoplasmic reticulum (SR), a specialized form of endoplasmic reticulum through the mechanism known as excitation-contraction (E-C) coupling. Following activation of skeletal muscle contraction by the E-C coupling mechanism, replenishment of intracellular stores requires reuptake of cytosolic Ca2+ into the SR by the activity of SR Ca2+-ATPases, but also Ca2+ entry from the extracellular space, through a mechanism called store-operated calcium entry (SOCE). The fine orchestration of these processes requires several proteins, including Ca2+ channels, Ca2+ sensors, and Ca2+ buffers, as well as the active involvement of mitochondria. Mutations in genes coding for proteins participating in E-C coupling and SOCE are causative of several myopathies characterized by a wide spectrum of clinical phenotypes, a variety of histological features, and alterations in intracellular Ca2+ balance. This review summarizes current knowledge on these myopathies and discusses available knowledge on the pathogenic mechanisms of disease
Functional brain network topology across the menstrual cycle is estradiol dependent and correlates with individual well-being
The menstrual cycle (MC) is a sex hormone-related phenomenon that repeats itself cyclically during the woman's reproductive life. In this explorative study, we hypothesized that coordinated variations of multiple sex hormones may affect the large-scale organization of the brain functional network and that, in turn, such changes might have psychological correlates, even in the absence of overt clinical signs of anxiety and/or depression. To test our hypothesis, we investigated longitudinally, across the MC, the relationship between the sex hormones and both brain network and psychological changes. We enrolled 24 naturally cycling women and, at the early-follicular, peri-ovulatory, and mid-luteal phases of the MC, we performed: (a) sex hormone dosage, (b) magnetoencephalography recording to study the brain network topology, and (c) psychological questionnaires to quantify anxiety, depression, self-esteem, and well-being. We showed that during the peri-ovulatory phase, in the alpha band, the leaf fraction and the tree hierarchy of the brain network were reduced, while the betweenness centrality (BC) of the right posterior cingulate gyrus (rPCG) was increased. Furthermore, the increase in BC was predicted by estradiol levels. Moreover, during the luteal phase, the variation of estradiol correlated positively with the variations of both the topological change and environmental mastery dimension of the well-being test, which, in turn, was related to the increase in the BC of rPCG. Our results highlight the effects of sex hormones on the large-scale brain network organization as well as on their possible relationship with the psychological state across the MC. Moreover, the fact that physiological changes in the brain topology occur throughout the MC has widespread implications for neuroimaging studies
Marginal sealing of relocated cervical margins of mesio-occluso-distal overlays.
We investigated the effect of cervical marginal relocation (CMR) on marginal sealing with two different viscosity resin composites, before adhesive cementation of composite computer-aided design/computer-assisted manufacture mesio-occluso-distal (MOD) overlays. Standardized MOD cavities prepared in 39 human molars were randomly assigned to three groups. The proximal margins on the mesial side were located 1 mm below the cementoenamel junction. On the distal side of the tooth, the margins were located 1 mm above the cementoenamel junction. In Groups 1 and 2, mesial proximal boxes were elevated with a hybrid composite (GC Essentia MD) and a flowable composite (GC G-ĂŠnial Universal Flo), respectively. CMR was not performed in Group 3. The overlays were adhesively cemented, and interfacial leakage was quantified by scoring the depth of silver nitrate penetration along the adhesive interfaces. Leakage score at the dentin-CMR composite interface did not significantly differ between the two tested composites but was significantly lower for Group 3. In all groups, scores were significantly higher at the dentin interface than at the enamel interface. These results indicate that the performance of flowable and microhybrid resin composites, as indicated by marginal sealing ability, is comparable for CMR
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