This study assessed the amount of unprepared surface areas at the apical 4-mm segment of the root canal after a planned preparation based on cone-beam computed tomography (CBCT) measurements.
...Eighteen posterior mandible segments were obtained from cadavers and scanned using CBCT and micro-computed tomographic (micro-CT) imaging. CBCT images were used to measure the largest initial canal diameter from 29 root canals of premolars at 1, 2, 3, and 4 mm short of the apical foramen. Each measurement was used to select a master apical instrument with size/taper that was 1 diameter larger to prepare the apical 4 mm of each particular root canal. A post-preparation micro-CT scan was obtained, and the unprepared canal areas were calculated.
A very high amount of surface areas over the apical 4 mm of the root canal was included in the final preparation (mean >90%). The unprepared areas ranged from as low as 3.7% to a maximum of 14.6% (mean and median, 9.2% and 9.1%, respectively).
The proposed planned apical root canal preparation resulted in optimized root canal shaping with a substantial amount of prepared surface areas. The protocol used also resulted in a conservative canal enlargement using final instruments that were 1 size larger than the initial largest canal diameter.
Plants are extensively used in traditional medicine, and several plant antimicrobial peptides have been described as potential alternatives to conventional antibiotics. However, after more than four ...decades of research no plant antimicrobial peptide is currently used for treating bacterial infections, due to their length, post-translational modifications or high dose requirement for a therapeutic effect . Here we report the design of antimicrobial peptides derived from a guava glycine-rich peptide using a genetic algorithm. This approach yields guavanin peptides, arginine-rich α-helical peptides that possess an unusual hydrophobic counterpart mainly composed of tyrosine residues. Guavanin 2 is characterized as a prototype peptide in terms of structure and activity. Nuclear magnetic resonance analysis indicates that the peptide adopts an α-helical structure in hydrophobic environments. Guavanin 2 is bactericidal at low concentrations, causing membrane disruption and triggering hyperpolarization. This computational approach for the exploration of natural products could be used to design effective peptide antibiotics.
The intermediate stages of dementia are relatively under-researched, including in Portugal. The Actifcare (ACcess to TImely Formal Care) EU-JPND project studied people with mild-moderate dementia, ...namely their needs, access to and use of community services (e.g., day centers, home support). In our baseline assessment of the Portuguese Actifcare cohort, the unmet needs of some participants would call for formal support, which was not always accessible or used. We now report the main results of the 12-month follow-up, analyzing changes in needs, service (non)use, quality of life and related variables.
This was a longitudinal, observational study using a convenience sample of 54 dyads of people with dementia and their family carers. Our main outcomes were the Camberwell Assessment of Need for the Elderly (CANE) and the Resources Utilization in Dementia. Clinical-functional, quality of life, psychological distress and caregiving-related assessments were also used.
At follow-up, the cognitive and functional status of people with dementia declined (p < 0.001), and their neuropsychiatric symptoms increased (p = 0.033). Considering CANE interviewers' ratings, the total needs of people with dementia increased at follow-up (p < 0.001) but not the unmet needs. Quality of life was overall stable. The use of formal care did not increase significantly, but informal care did in some domains. Carers' depressive symptoms increased (p = 0.030) and perseverance time decreased (p = 0.045). However, carers' psychological distress unmet needs were lower (p = 0.007), and their stress and quality of life remained stable.
People with dementia displayed complex biopsychosocial unmet needs. Their cognitive-functional decline over one year was not accompanied by a corresponding increase in any pattern of unmet need, nor of service use. Reliance on informal care (namely supervision) may have contributed to this. Caregiving-related outcomes evolved according to different trends, although stability was almost the rule. Primary carers were even more present at follow-up, without an apparently heavier toll on their own needs, burden, and quality of life. Overall, this longitudinal study comprehensively assessed Portuguese community-dwelling people with dementia. Despite the lack of generalizability, participants' needs remained overall stable and partly unmet over one year. Longer follow-up periods are needed to understand such complex processes.
Abstract
Complex organic molecules have been observed for decades in the interstellar medium. Some of them might be considered as small bricks of the macromolecules at the base of terrestrial life. ...It is hence particularly important to understand organic chemistry in Solar-like star-forming regions. In this article, we present a new observational project: Seeds Of Life In Space (SOLIS). This is a Large Project using the IRAM-NOEMA interferometer, and its scope is to image the emission of several crucial organic molecules in a sample of Solar-like star-forming regions in different evolutionary stages and environments. Here we report the first SOLIS results, obtained from analyzing the spectra of different regions of the Class 0 source NGC 1333-IRAS4A, the protocluster OMC-2 FIR4, and the shock site L1157-B1. The different regions were identified based on the images of formamide (NH
2
CHO) and cyanodiacetylene (HC
5
N) lines. We discuss the observed large diversity in the molecular and organic content, both on large (3000–10,000 au) and relatively small (300–1000 au) scales. Finally, we derive upper limits to the methoxy fractional abundance in the three observed regions of the same order of magnitude of that measured in a few cold prestellar objects, namely
–10
−11
with respect to H
2
molecules.
Aim
To compare in vitro the sealing ability of root‐end fillings with mineral trioxide aggregate (MTA) and EndoSequence BioCeramic Root Repair Material‐Fast Set (BC‐RRM) Putty using a novel bacterial ...nutrient leakage model, which provides information on whether or not intracanal bacteria are receiving nutrients from serum via leakage channels.
Methodology
Sixty single‐rooted decoronated mandibular incisors with instrumented root canals were subjected to root‐end resection and ultrasonic preparation. The root specimens were mounted in the experimental apparatus, and the root‐end cavities filled with the test materials. The positive control group used warm Gutta‐percha and no sealer. In the negative controls, the entire resected surface was covered with varnish. After sterilization in ethylene oxide, the root canal was inoculated with 1.5 × 105 washed cells of Enterococcus faecalis. The apparatus was filled with foetal bovine serum, leaving only the apical root immersed. After 30‐day incubation, samples were taken from the canal, cultured and the colony‐forming units (CFUs) counted. Statistical analysis was performed using the Mann–Whitney test for quantitative and the Fisher exact test for qualitative data.
Results
In the MTA group, 10 of 20 (50%) specimens still had detectable viable bacteria in the canals (mean, 8.97 × 103 CFUs). In the BC‐RRM Putty group, 5 of 18 (28%) specimens were positive for bacterial growth (mean, 2.88 × 104 CFUs). There was no significant difference when comparing the quantitative or presence/absence data from the MTA and BC‐RRM Putty groups. Positive and negative controls yielded the expected results.
Conclusions
MTA and BC‐RRM Putty had similar sealing ability. The experimental model was effective in determining whether or not residual intracanal bacteria could survive by receiving nutrients from outside.
To determine the validity of the Manchester Triage System (MTS) in emergency care for the general population of patients attending the emergency department, for children and elderly, and for commonly ...used MTS flowcharts and discriminators across three different emergency care settings.
This was a prospective observational study in three European emergency departments. All consecutive patients attending the emergency department during a 1-year study period (2010-2012) were included. Validity of the MTS was assessed by comparing MTS urgency as determined by triage nurses with patient urgency according to a predefined 3-category reference standard as proxy for true patient urgency.
288,663 patients were included in the analysis. Sensitivity of the MTS in the three hospitals ranged from 0.47 (95%CI 0.44-0.49) to 0.87 (95%CI 0.85-0.90), and specificity from 0.84 (95%CI 0.84-0.84) to 0.94 (95%CI 0.94-0.94) for the triage of adult patients. In children, sensitivity ranged from 0.65 (95%CI 0.61-0.70) to 0.83 (95%CI 0.79-0.87), and specificity from 0.83 (95%CI 0.82-0.83) to 0.89 (95%CI 0.88-0.90). The diagnostic odds ratio ranged from 13.5 (95%CI 12.1-15.0) to 35.3 (95%CI 28.4-43.9) in adults and from 9.8 (95%CI 6.7-14.5) to 23.8 (95%CI 17.7-32.0) in children, and was lowest in the youngest patients in 2 out of 3 settings and in the oldest patients in all settings. Performance varied considerably between the different emergency departments.
Validity of the MTS in emergency care is moderate to good, with lowest performance in the young and elderly patients. Future studies on the validity of triage systems should be restricted to large, multicenter studies to define modifications and improve generalizability of the findings.
Implications of Kleinian relativity Alves-Júnior, F. A. P.; Barreto, A. B.; Moraes, F.
Physical review. D,
02/2021, Letnik:
103, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Inspired in metamaterials, we present a covariant mechanics for particles in Kleinian spacetime and show some of its effects, such as time contraction and length dilatation. We present the new ...expressions for relativistic momentum and energy for a pointlike particle. To illustrate the new mechanics, we describe the particle motion under a uniform Newtonian gravitational field. We also revisit the free spin-half particle problem in Kleinian spacetime, discuss some quantum implications, like the constraint on the dispersion relation for Weyl fermions, and adapt a metamaterial analog system to Klein spacetime.
The relationship between rooting depth and above‐ground hydraulic traits can potentially define drought resistance strategies that are important in determining species distribution and coexistence in ...seasonal tropical forests, and understanding this is important for predicting the effects of future climate change in these ecosystems.
We assessed the rooting depth of 12 dominant tree species (representing c. 42% of the forest basal area) in a seasonal Amazon forest using the stable isotope ratios (δ18O and δ2H) of water collected from tree xylem and soils from a range of depths. We took advantage of a major ENSO‐related drought in 2015/2016 that caused substantial evaporative isotope enrichment in the soil and revealed water use strategies of each species under extreme conditions. We measured the minimum dry season leaf water potential both in a normal year (2014; Ψnon‐ENSO) and in an extreme drought year (2015; ΨENSO). Furthermore, we measured xylem hydraulic traits that indicate water potential thresholds trees tolerate without risking hydraulic failure (P50 and P88).
We demonstrate that coexisting trees are largely segregated along a single hydrological niche axis defined by root depth differences, access to light and tolerance of low water potential. These differences in rooting depth were strongly related to tree size; diameter at breast height (DBH) explained 72% of the variation in the δ18Oxylem. Additionally, δ18Oxylem explained 49% of the variation in P50 and 70% of P88, with shallow‐rooted species more tolerant of low water potentials, while δ18O of xylem water explained 47% and 77% of the variation of minimum Ψnon‐ENSO and ΨENSO.
We propose a new formulation to estimate an effective functional rooting depth, i.e. the likely soil depth from which roots can sustain water uptake for physiological functions, using DBH as predictor of root depth at this site. Based on these estimates, we conclude that rooting depth varies systematically across the most abundant families, genera and species at the Tapajós forest, and that understorey species in particular are limited to shallow rooting depths.
Our results support the theory of hydrological niche segregation and its underlying trade‐off related to drought resistance, which also affect the dominance structure of trees in this seasonal eastern Amazon forest.
Synthesis. Our results support the theory of hydrological niche segregation and demonstrate its underlying trade‐off related to drought resistance (access to deep water vs. tolerance of very low water potentials). We found that the single hydrological axis defining water use traits was strongly related to tree size, and infer that periodic extreme droughts influence community composition and the dominance structure of trees in this seasonal eastern Amazon forest.
Our results support the theory of hydrological niche segregation and demonstrate its underlying trade‐off related to drought resistance (access to deep water vs. tolerance of very low water potentials). We found that the single hydrological axis defining water use traits was strongly related to tree size, and infer that periodic extreme droughts influence community composition and the dominance structure of trees in this seasonal eastern Amazon forest.
This study compared the efficacy of HyFlex NT (HF; Coltene, New York, NY) and Mani GPR (MN; Mani Inc, Tokyo, Japan) systems followed by a supplementary approach with passive ultrasonic irrigation ...(PUI) in removing the filling material from curved root canals during retreatment. The mesial canals from 20 extracted mandibular molars with Vertucci type IV configuration were instrumented and obturated (N = 40). Each mesial canal was retreated using either HF or MN instruments, alternating the system used per canal from root to root. The final preparation size was 40/0.04 for both systems. The volume of canal filling material was assessed by means of micro–computed tomographic (micro-CT) imaging before and after retreatment, and the working time was recorded. Canals still showing remnants of filling material were subjected to a supplementary approach with PUI, and another micro-CT scan was taken. The percentage of filling material removed with MN instruments and HF was similar (95.5% and 92.7%, respectively) (P > .05). MN required significantly less time to remove the filling material (P < .05). The supplementary approach with PUI significantly enhanced the removal of filling material (P < .05). Both systems were equally effective in removing the root canal filling during retreatment. MN was faster than HF. The supplementary approach with PUI significantly improved filling material removal.
•The amount of filling material removed with Mani GPR and HyFlex NT was similar.•Mani GPR required less time to remove the filling material than HyFlex NT.•Passive ultrasonic irrigation significantly enhanced the removal of filling material.
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