177,119 research outputs found
Ionic permeability on isolated mouse liver nuclei: influence of ATP and Ca2+
No full textPatch-clamp experiments on isolated nuclei revealed the existence of ionic channels on the nuclear envelope, but their exact localization and function are still unknown. Recent studies have demonstrated that ATP and calcium ions play an important role in nucleocytoplasmic protein traffic. ATP is essential to allow big molecules in and out of the nucleus. However, a cytoplasmic rise of calcium ions above 300 nm decreases both ATP-dependent transport and passive diffusion through the nuclear envelope. The use of isolated nuclei placed in a saline solution provides the possibility for testing only the compounds added in the bath or in the recording pipette. In the present study, we show that ATP is responsible for an increase of nuclear ionic permeability on isolated nuclei. This result not only confirms data previously reported in in situ nuclei, but also suggests that ATP is directly involved in the modulation of passive ionic permeability. In these particular experimental conditions, calcium ions decrease the channel current starting from a concentration of 1 microM. The parallelism in the modulation action of ATP and Ca++ between nuclear pores and ionic channels present on the nuclear envelope contributes to the support of the idea that an ionic pathway is associated with the pore complex
Idiopathic hypoplasia of the masseter muscle: a case report
No full textObjective and importance: Hypoplasia of the masseter muscle is a rare condition, described as partial or total, associated with congenital malformations or pathologies. Rare cases are those with no genetic alterations in their familiar picture. The authors present a case of an idiopathic masseter muscle hypoplasia in the absence of other pathologies.
Clinical presentation: The case report involved a patient who presented to the consultant clinic complaining of facial asymmetry. The patient underwent several exams to confirm the diagnosis of masseter muscle hypoplasia, which included an X-ray, magnetic resonance of the temporomandibular articulation, and electromyography. Intervention: The patient was treated with a customized functional appliance and fixed orthodontic treatment with satisfactory functional and esthetic results.
Conclusion: The case presented highlights the possibility of finding a hypoplasia of the masseter muscle even in the absence of other pathologies and without specific clinical symptoms, and how to plan an appropriate treatment with functional appliance and fixed orthodontic therapy
Cytoskeletal control of rectification and expression of four substates in cardiac inward rectifier K+ channels
No full textCardiac inward rectifiers may have a three-barrel channel structure, based on evidence for three substates in single-channel recordings. However, some reports indicate four substates, a feature more compatible with the four-subunit structure for which there is evidence in cloned voltage-activated K+ channels. Here we show that although the fourth is easily missed, inward rectifier channels have four substates whose expression is controlled by intracellular Ca(2+) ions. Fourth substate openings also appear after rectification loss in intracellular divalent caution-free solution. We find that this process is accelerated by cytochalasin, a microfilament disrupter. Cytochalasin also abolishes Ca(2+), but not Mg(2+),-induced rectification by restoring fourth substate openings. Thus, cytoskeletal elements control Ca(2+)-dependent substate expression and rectification in native inwardly rectifying K+ channels
Characterization of the inner membrane components of the protein machinery required for the transport of lipopolysaccharide to the outer membrane of Escherichia coli
No full textOuter membrane biogenesis in E. coli: characterization of an inner membrane protein complex involved in LPS transport
No full textRisonanza Propriocettiva Globale : effetti sul sistema posturale - Global Proprioceptive Resonance : effects on postural system
No full textObiettivo: Lo scopo di questo studio è stato studiare gli effetti di una struttura ergonomica a Vibrazione Multifocale (MFV) sull’equilibrio corporeo in soggetti sani, ed individuare una correlazione tra l'equilibrio posturale e una struttura ergonomica che porta ad un rilascio neuromuscolare e una ridistribuzione dei carichi plantari.
Materiali e Metodi: Trenta volontari (sedici maschi e quattordici femmine, di età compresa tra 19-25 anni) sono stati sottoposti all’esame stabilometrico prima della MFV (tempo T0) e subito dopo la MFV (tempo T1). I soggetti presentavano una I classe molare e canina, simmetria del viso, assenza di patologie temporomandibolari e malattie sistemiche. Keope è la struttura ergonomica utilizzata in questo protocollo: dà un beneficio psico-fisico grazie alla somministrazione di vibrazioni multifocali. In questo studio è stata utilizzata la Pedana Stabiometrica Biopostural.
Risultati: Dal punto di vista posturale, vi è stato un miglioramento della distribuzione dei carichi e nella posizione del baricentro secondo l'asse ideale. Ci sono stati effetti statisticamente significativi nei test di equilibrio posturale (p <0.05).
Conclusioni: Anche se questo è uno studio preliminare, è possibile affermare che la struttura ergonomica Keope induce cambiamenti importanti nel sistema posturale. Ulteriori studi futuri dovrebbero concentrarsi sulla valutazione degli effetti sui pazienti ortodontici e disfunzionali, così come gli effetti a lungo termine.Aim: The purpose of this study was to investigate the effects of an ergonomic structure by Multifocal Vibrations (MFV) on body balance in healthy subjects. The aim was to find out a correlation between the postural equilibrium and an ergonomic structure that leads to a muscular release and a redistribution of plantar loads. The sample was analyzed at time T0 (before the ergonomic structure) and at time T1 (after the ergonomic structure).
Materials and Methods: Thirty volunteers (sixteen males and fourteen females, aged 19-25 years) underwent stabilometry before (time T0) the Multifocal Vibration and immediately after it (time T1). The subjects were I molar and canine class, with facial symmetry, without temporomandibular diseases and systemic diseases. Keope is the ergonomic structure used in this protocol: it gives a psyco-physical release thanks to Multifocal Vibrations. Biopostural system platform was used in this study.
Results: From a postural point of view, there was an improvement in the loads distribution and in the position of the barycenter according to the ideal axis. There were statistically significant effects in body balance tests (p<0.05).
Conclusions: Although this is a preliminary study, it’s possible to affirm that the MFV leads to important changes in the postural system. Further and future studies should focus on evaluating the effects on orthodontic and temporomandibular disease patients, as well as the long term effects
An assessment of the current and historical distribution of the Corncrake Crex crex in the Western Italian Alps
No full textAgricultural intensification and mechanization are major threats to farmland birds in Europe. The Corncrake Crex crex was a common and widespread species in rural landscapes in Italy, but its numbers strongly declined in most of its former range in the last half of the 20th century. Although it is a well-studied species in the Eastern Italian Alps, where most of the Italian population now occurs, there is no published information from the Western part of the range. This study aimed to describe the distribution of the Corncrake in the regions of Piedmont and Aosta Valley, taking into account both historical and recent records. Additionally, we assessed the habitat in which apparently breeding individuals were found. Overall, 78 occurrences of this species were recorded in the study region. Migrating individuals occurred at lower elevations, whilst possible breeding records were located at higher elevations in meadow-pastures and secondary grasslands. Two main current hotspots were identified in the Chisone Valley and in the valleys in the province of Cuneo, which represent the core areas for the species in Piedmont and Aosta Valley. The observation trend shows a possible recovery of the population at the regional scale, although a large-scale dedicated survey is needed to estimate population size. In 2020, the highest number of singing males in one site (5) was recorded with individuals observed above 1800 m. Conservation measures at a regional scale addressing grassland management (including mowing and grazing) might benefit the species and promote a wider recolonization of the area
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
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