26 resultados para TAP
Resumo:
To ascertain whether reactive oxygen species (ROS) contribute to training-induced adaptation of skeletal muscle, we administered ROS-scavenging antioxidants (AOX; 140 mg/l of ascorbic acid, 12 mg/l of coenzyme Q10 and 1% N-acetyl-cysteine) via drinking water to 16 C57BL/6 mice. Sixteen other mice received unadulterated tap water (CON). One cohort of both groups (CON(EXE) and AOX(EXE) ) was subjected to treadmill exercise for 4 weeks (16-26 m/min, incline of 5°-10°). The other two cohorts (CON(SED) and AOX(SED) ) remained sedentary. In skeletal muscles of the AOX(EXE) mice, GSSG and the expression levels of SOD-1 and PRDX-6 were significantly lower than those in the CON(EXE) mice after training, suggesting disturbance of ROS levels. The peak power related to the body weight and citrate synthase activity was not significantly influenced in mice receiving AOX. Supplementation with AOX significantly altered the mRNA levels of the exercise-sensitive genes HK-II, GLUT-4 and SREBF-1c and the regulator gene PGC-1alpha but not G6PDH, glycogenin, FABP-3, MCAD and CD36 in skeletal muscle. Although the administration of AOX during endurance exercise alters the expression of particular genes of the ROS metabolism, it does not influence peak power or generally shift the metabolism, but it modulates the expression of specific genes of the carbohydrate and lipid metabolism and PGC-1alpha within murine skeletal muscle.
Resumo:
We present a conceptual prototype model of a focal plane array unit for the STEAMR instrument, highlighting the challenges presented by the required high relative beam proximity of the instrument and focus on how edge-diffraction effects contribute to the array's performance. The analysis was carried out as a comparative process using both PO & PTD and MoM techniques. We first highlight general differences between these computational techniques, with the discussion focusing on diffractive edge effects for near-field imaging reflectors with high truncation. We then present the results of in-depth modeling analyses of the STEAMR focal plane array followed by near-field antenna measurements of a breadboard model of the array. The results of these near-field measurements agree well with both simulation techniques although MoM shows slightly higher complex beam coupling to the measurements than PO & PTD.
Resumo:
The reliability of millimeter and sub-millimeter wave radiometer measurements is dependent on the accuracy of the loads they employ as calibration targets. In the recent past on-board calibration loads have been developed for a variety of satellite remote sensing instruments. Unfortunately some of these have suffered from calibration inaccuracies which had poor thermal performance of the calibration target as the root cause. Stringent performance parameters of the calibration target such as low reflectivity, high temperature uniformity, low mass and low power consumption combined with low volumetric requirements remain a challenge for the space instrument developer. In this paper we present a novel multi-layer absorber concept for a calibration load which offers an excellent compromise between very good radiometric performance and temperature uniformity and the mass and volumetric constraints required by space-borne calibration targets.
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Objectives: To investigate surface roughness and microhardness of two recent resin-ceramic materials for computer-aided design/computer-aided manufacturing (CAD/CAM) after polishing with three polishing systems. Surface roughness and microhardness were measured immediately after polishing and after six months storage including monthly artificial toothbrushing. Methods: Sixty specimens of Lava Ultimate (3M ESPE) and 60 specimens of VITA ENAMIC (VITA Zahnfabrik) were roughened in a standardized manner and polished with one of three polishing systems (n=20/group): Sof-Lex XT discs (SOFLEX; three-step (medium-superfine); 3M ESPE), VITA Polishing Set Clinical (VITA; two-step; VITA Zahnfabrik), or KENDA Unicus (KENDA; one-step; KENDA Dental). Surface roughness (Ra; μm) was measured with a profilometer and microhardness (Vickers; VHN) with a surface hardness indentation device. Ra and VHN were measured immediately after polishing and after six months storage (tap water, 37°C) including monthly artificial toothbrushing (500 cycles/month, toothpaste RDA ~70). Ra- and VHN-values were analysed with nonparametric ANOVA followed by Wilcoxon rank sum tests (α=0.05). Results: For Lava Ultimate, Ra (mean [standard deviation] before/after storage) remained the same when polished with SOFLEX (0.18 [0.09]/0.19 [0.10]; p=0.18), increased significantly with VITA (1.10 [0.44]/1.27 [0.39]; p=0.0001), and decreased significantly with KENDA (0.35 [0.07]/0.33 [0.08]; p=0.03). VHN (mean [standard deviation] before/after storage) decreased significantly regardless of polishing system (SOFLEX: 134.1 [5.6]/116.4 [3.6], VITA: 138.2 [10.5]/115.4 [5.9], KENDA: 135.1 [6.2]/116.7 [6.3]; all p<0.0001). For VITA ENAMIC, Ra (mean [standard deviation] before/after storage) increased significantly when polished with SOFLEX (0.37 [0.18]/0.41 [0.14]; p=0.01) and remained the same with VITA (1.32 [0.37]/1.31 [0.40]; p=0.58) and with KENDA (0.81 [0.35]/0.78 [0.32]; p=0.21). VHN (mean [standard deviation] before/after storage) remained the same regardless of polishing system (SOFLEX: 284.9 [24.6]/282.4 [31.8], VITA: 284.6 [28.5]/276.4 [25.8], KENDA: 292.6 [26.9]/282.9 [24.3]; p=0.42-1.00). Conclusion: Surface roughness and microhardness of Lava Ultimate was more affected by storage and artificial toothbrushing than was VITA ENAMIC.
Resumo:
In eukaryotic cells, translation of messenger RNA (mRNA) can be initiated either on transcripts associated with the cap-binding complex (CBC; consisting of CBP80 and CBP20) or on transcripts with the eukaryotic translation initiation factor (eIF) 4E bound to the cap. Together with eIF4G and eIF4A, eIF4E forms the eIF4F-complex, which mediates translation initiation during the bulk of cellular protein synthesis. Functionally substituting for eIF4G, the CBP80/20-dependent translation initiation factor (CTIF) has been reported to be part of the CBC-dependent translation initiation complex 1,2. CTIF consists of a N-terminal CBP80-binding domain and a conserved C-terminal MIF4G domain 1. This MIF4G domain has been shown to mediate the interaction between CTIF and different factors such as eIF3g and the stem-loop binding protein (SLBP) 2,3. Here we provide evidence that CTIF, besides its function in translation initiation, is also involved in mRNA translocation from the nucleus to the cytoplasm, possibly through a direct interaction with the nuclear export factor NFX1/TAP. Taken together our results suggest that CTIF can function as a platform that interacts with proteins involved in different steps of the mRNA metabolism.
Resumo:
In eukaryotic cells translation initiation of messenger RNA (mRNA) transcripts can be initiated either by the cap-binding complex (CBC) consisting of CBP80 and CBP20, or by the eukaryotic translation initiation factor (eIF) 4E. Together with eIF4G and eIF4A, eIF4E forms the eIF4F-complex, which mediates initiation of the bulk of cellular translation. Analogous to eIF4G, the CBP80/20-dependent translation initiation factor (CTIF) has been reported to be part of the CBC-dependent translation initiation complex. CTIF consists of a N-terminal CBP80-binding domain and a conserved C-terminal MIF4G domain. This MIF4G domain has been shown to mediate the interaction between CTIF and different factors such as eIF3g and the stem-loop binding protein (SLBP). Here we show data indicating that CTIF, besides its function in translation initiation, is involved in mRNA translocation from the nucleus to the cytoplasm, possibly through a direct interaction with the nuclear export factor NFX1/TAP. Taken together our results suggest that CTIF can function as a platform that interacts with proteins involved in different steps of mRNA metabolism.
Resumo:
OBJECTIVES The aim of this study was to assess the preventive effect of a fluoride-, stannous- and chitosan-containing (F/Sn/chitosan-) toothpaste (TP) on initial enamel erosion and abrasion. METHODS In total, 150 human premolar enamel specimens were ground, polished and divided into 5 toothpaste/rinse groups (n=30): (G1) placebo-TP/tap water, (G2) sodium fluoride (NaF-) TP/tap water, (G3) F/Sn/chitosan-TP/tap water, (G4) F/Sn/chitosan-TP/Sn-rinse, (G5) NaF-TP/NaF-rinse. The 8-day erosion-abrasion cyclic treatment (one cycle/day) consisted of incubating the samples in artificial saliva (30min), then submitting the samples to toothbrush abrasion (2min incubation in toothpaste slurry; brushing with 20 toothbrush strokes) and rinsing (2min; 10ml) with the respective solution: tap water (G1-G3), Sn-rinse (G4) or NaF-rinse (G5). Afterwards, the samples were submitted to erosion (2min; 30ml 1% citric acid, pH=3.6). Surface microhardness (SMH) was measured initially and after every abrasion and erosion treatment. Enamel substance loss was calculated after each abrasion. Non-parametric ANOVA followed by Wilcoxon rank tests were used for analysis. RESULTS G1 presented the greatest SMH decrease, while G4 presented the least SMH decrease (p<0.001). G3 had a similar SMH decrease to G2 and G5. Substance loss was significantly lower in G4 than all other groups (p<0.05), closely followed by G3. Both G2 and G5 showed similar calculated enamel substance loss to G1. CONCLUSION The treatment with F/Sn/chitosan-TP and tap water provided a similar SMH decrease to both NaF-TP groups, but significantly lower substance loss. F/Sn/Chitosan-TP and Sn-rinse showed a better preventive effect, which promoted less SMH decrease and reduced substance loss. CLINICAL SIGNIFICANCE The toothpaste containing fluoride, stannous and chitosan shows promising results in reducing substance loss from erosion and abrasion. The combination of this toothpaste with the stannous-containing rinse showed even better prevention against erosion-abrasion.
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Background: Defining learning goals (LG) in alignment with learning needs (LN) is one of the key purposes of formative workplace-based assessment, but studies about this topic are scarce. Summary of Work: We analysed quantitatively and qualitatively how often trainer-student pairs identified the same LN during Mini Clinical Evaluation Exercises (Mini-CEX) in clerkships and to what degree those LNs were in line with the recorded LGs. Multilevel logistic regression models were used to predict LGs by identified LNs, controlling for context variables. Summary of Results: 512 trainers and 165 students conducted 1783 Mini-CEX (98% completion rate). Concordantly, trainer-student pairs most often identified LNs in the domains ‘clinical reasoning’ (23% of 1167 complete forms), ‘organisation / efficiency’ (20%) and ‘physical examination’ (20%). At least one ‘defined’ LG was noted on 313 student forms (18% of 1710), with a total of 446 LGs. Of these, the most frequent LGs were ‘physical examination’ (49% of 446 LGs) and ‘history taking’ (21%); corresponding LNs as well as context variables (e.g. clinic size) were found to be predictors of these LGs. Discussion and Conclusions: Although trainer-student pairs often agreed in their identified LNs, many assessments did not result in an aligned LG or a LG at all. Interventions are needed to enhance the proportion of (aligned) LGs in Mini-CEX in order to tap into its full potential not only as a ‘diagnostic’ but also as an ‘educational tool’. Take-home messages: The sparseness of LGs, their dependency on context variables and their partial non-alignment with students’ LNs raise the question of how the effectiveness of Mini-CEX can be further enhanced.
Resumo:
In eukaryotic cells translation initiation of messenger RNA (mRNA) transcripts can be initiated either by the cap-binding complex (CBC) consisting of CBP80 and CBP20, or by the eukaryotic translation initiation factor (eIF) 4E. Together with eIF4G and eIF4A, eIF4E forms the eIF4F-complex, which mediates translation initiation during the bulk of cellular protein synthesis [1,2]. Functionally analogous to eIF4G, the CBP80/20-dependent translation initiation factor (CTIF) has been reported to be part of the CBC-dependent translation initiation complex [3,4]. CTIF consists of a N-terminal CBP80-binding domain and a conserved C-terminal MIF4G domain [3]. This MIF4G domain has been shown to mediate the interaction between CTIF and different factors such as eIF3g and the stem-loop binding protein (SLBP) [4,5]. Here we show data indicating that CTIF, besides its function in translation initiation, is involved in mRNA translocation from the nucleus to the cytoplasm, possibly through a direct interaction with the nuclear export factor NFX1/TAP. Taken together our results suggest that CTIF can function as a platform that interacts with proteins involved in different steps of the mRNA metabolism. [1] Haghighat A. and Sonenberg N. (1997) JBC 272:21677-21680 [2] Gross J.D. et al. (2003) Cell 115:739-750 [3] Kim K.M. et al. (2009) Genes Dev 23:2033-2045 [4] Choe J. et al. (2012) JBC 287:18500-18509 [5] Choe J. et al. (2013) NAR 41:1307-1318
Resumo:
OBJECTIVE To assess the in vivo amount of BPA released from a visible light-cured orthodontic adhesive, immediately after bracket bonding. METHODS 20 orthodontic patients were recruited after obtaining informed consent. All patients received 24 orthodontic brackets in both dental arches. In Group A (11 patients), 25 ml of tap water were used for mouth rinsing, whereas in Group B (9 patients) a simulated mouth rinse formulation was used: a mixture of 20 ml de-ionized water plus 5 ml absolute ethanol. Rinsing solutions were collected before, immediately after placing the orthodontic appliances and after washing out the oral cavity and were then stored in glass tubes. Rinsing was performed in a single phase for 60s with the entire volume of each liquid. The BPA analysis was performed by gas chromatography-mass spectrometry. RESULTS An increase in BPA concentration immediately after the 1st post-bonding rinse was observed, for both rinsing media, which was reduced after the 2nd post-bonding rinse. Water exhibited higher levels of BPA concentration than water/ethanol after 1st and 2nd post-bonding rinses. Two-way mixed Repeated Measures ANOVA showed that the primary null hypothesis declaring mean BPA concentration to be equal across rinsing medium and rinsing status was rejected (p-value <0.001). The main effects of the rinsing medium and status, as well as their interaction were found to be statistically significant (p-values 0.048, <0.001 and 0.011 respectively). SIGNIFICANCE A significant pattern of increase of BPA concentration, followed by a decrease that reached the initial values was observed. The amount of BPA was relatively low and far below the reference limits of tolerable daily intake.
Resumo:
Cysteine proteases mediate liberation of Plasmodium berghei merozoites from infected hepatocytes. In an attempt to identify the responsible parasite proteases, we screened the genome of P. berghei for cysteine protease-encoding genes. RT-PCR analyses revealed that transcription of four out of five P. berghei serine repeat antigen (PbSERA) genes was strongly upregulated in late liver stages briefly before the parasitophorous vacuole membrane ruptured to release merozoites into the host cell cytoplasm, suggesting a role of PbSERA proteases in these processes. In order to characterize PbSERA3 processing, we raised an antiserum against a non-conserved region of the protein and generated a transgenic P. berghei strain expressing a TAP-tagged PbSERA3 under the control of the endogenous promoter. Immunofluorescence assays revealed that PbSERA3 leaks into the host cell cytoplasm during merozoite development, where it might contribute to host cell death or activate host cell proteases that execute cell death. Importantly, processed PbSERA3 has been detected by Western blot analysis in cell extracts of schizont-infected cells and merozoite-infected detached hepatic cells.