Objective
This study aimed to compare 3 reciprocating systems regarding design, metallurgy, mechanical properties, and shaping ability.
Materials and methods
New Reciproc Blue R25, WaveOne Gold ...Primary, and REX 25 instruments (
n
=41 per group) were analyzed regarding design, metallurgy, and mechanical performance, while shaping ability (untouched canal walls, volume of removed dentin, and hard tissue debris) was tested in 36 anatomically matched root canals of mandibular molars. Results were compared using one-way ANOVA post hoc Tukey and Kruskal–Wallis tests with a significant level set at 5%.
Results
All instruments showed symmetrical cross sections with asymmetrical blades, no radial lands, no major defects, and an almost equiatomic nickel and titanium ratio. The highest R-phase start temperatures were observed with WaveOne Gold (46.1°C) and REX (44.8°C), while Reciproc Blue had the lowest R-phase start (34.5°C) and finish (20°C) temperatures. WaveOne Gold had the lowest time to fracture (169 s) and the highest maximum load (301.6 gf) (
P
<0.05). The maximum torque of Reciproc Blue (2.2 N.cm) and WaveOne Gold (2.1 N.cm) were similar (
P
>0.05), but lower than REX (2.6 N.cm) (
P
<0.05). No statistical differences were observed among instruments in the angle of rotation (
P
>0.05) and in the shaping ability in both mesial and distal canals (
P
>0.05).
Conclusion
Although the overall design, temperature transition phases and mechanical behavior parameters were different among tested instruments, they were similar in terms of shaping ability.
Clinical relevance
All tested heat-treated NiTi reciprocating systems showed similar shaping ability, without clinically significant errors.
Organizational agility (OA), as a key dynamic capability, is a firm's ability to enable sensing environmental changes and responding efficiently and effectively to them. This study explores this ...topic further by analyzing the part that the information systems capabilities (ISC) variable plays as an antecedent of OA, and absorptive capacity (AC) as a mediator construct. Furthermore, this study tests the negative moderating role of hierarchy culture (HC) in the AC–OA link. Using partial least squares (PLS) and the PROCESS macro, this work finds evidence of these relations proposed, and the existence of a conditional mediating situation that HC generates. In addition, the main model with direct effects (ISC and AC as predictors) achieves an appropriate level of predictive validity for the key endogenous construct (OA).
Male Holstein calves commonly receive minimal quantities of milk replacer (MR) to speed up weaning and reduce costs. Studies with Holstein female calves show that early life feed restriction affects ...energy metabolism later in life. Aiming to test this hypothesis, 120 Holstein bull calves (48.4 ± 2.2 kg of BW and 20 ± 3.2 d of age) housed in 24 pens were blocked and randomized to two treatments: A low calf MR allowance (LP) (two daily doses of 2 l each, 582 g/d of DM), or a high MR allowance (HP) (two daily meals of 4 l each, 1164 g/d of DM). Calves were weaned at day 49 of the study and slaughtered at 32.8 ± 0.5 weeks of age. Throughout the study, animals had ad libitum access to a common compound feed, straw, and water. Twenty-four animals were randomly selected for an intravenous glucose tolerance test (IVGTT). The IVGTT was performed at week 6 and 12 of the study and consisted of an intravenous glucose infusion and sequential blood sampling up to 90 min after glucose infusions. Calves were heavier for HP until week 12, after which the difference disappeared. By design, the MR intake was higher in the HP group resulting in a higher energy intake and a higher average daily gain in the preweaning phase. Blood glucose curves were not different at week 6, but at week 12, 5 min after the infusion, glucose was higher in HP calves. Insulin curves were not different at week 6. Nevertheless, in week 12, a higher insulin concentration was observed for HP 5, 10, 15, 20, 30, 35, and 45 min’ postinfusion, indicating a higher requirement of insulin to control glycemia. Differences between HP and LP calves were also observed for the quantitative insulin sensitivity check index, maximum insulin concentration, and insulin delta at week 12. Blood glucose reached maximum concentration within 5–10 min of the IVGTT test, and the concentration was, on average, 8.58 and 10.80 mmol/l at weeks 6 and 12, respectively. Insulin reached maximum concentration within 10–15 min of the IVGTT, and concentrations were, on average, 33.32 and 32.61 μUI/ml at weeks 6 and 12, respectively. Doubling MR supply improved animal growth up to weaning, but these differences disappeared by the end of the feeding period. Despite similar responses to glucose infusions preweaning, higher milk supply seemed to decrease insulin sensitivity after weaning.
When supplementing lamb diets with vitamin E, an equivalence factor of 1.36 is used to discriminate between RRR-α-tocopheryl acetate and all-rac-α-tocopheryl acetate. However, more recent studies ...suggest a need for new equivalence factors for livestock animals. The current study aimed to determine the effect of RRR- and all-rac-α-tocopheryl acetate supplementation on α-tocopherol deposition in lamb tissues. A total of 108 Rasa Aragonesa breed lambs were fed increasing amounts of all-rac-α-tocopheryl acetate (0.25, 0.5, 1.0 and 2.0 g/kg compound feed) or RRR-α-tocopheryl acetate (0.125, 0.25, 0.5 and 1.0 g/kg compound feed) by adding them to a basal diet that contained 0.025 g/kg feed of all-rac-α-tocopheryl acetate as part of the standard vitamin and mineral mixture. The diets were fed for the last 14 days before slaughtering at 25.8±1.67 kg BW. Within 20 min after slaughter samples of muscle, heart, liver, brain and spleen were frozen at −20°C until α-tocopherol analysis. Increased supplementation of either vitamin E sources led to a significant increase (P < 0.001) in α-tocopherol concentration in all tissues studied. The tissue with the highest α-tocopherol concentration was the liver followed by spleen, heart and muscle. At similar supplementation levels (0.25, 0.50 and 1.0 g/kg compound feed), α-tocopherol content in the selected tissues was not affected by α-tocopherol source. However, the ratios between RRR- and all-rac-α-tocopheryl acetate increased with the increasing α-tocopherol supplementation (at 0.25 and 1.0 g/kg compound feed), from 1.06 to 1.16 in muscle, 1.07 to 1.15 in heart, 0.91 to 0.94 in liver and 0.98 to 1.10 in spleen. The highest relative proportion of Ʃ2S (sum of SSS-, SSR-, SRS- and SRR-α-tocopherol)-configured stereoisomers was found in the liver of lambs supplemented with all-rac-α-tocopheryl acetate accounting for up to 35 to 39% of the total α-tocopherol retained, whereas the proportion of Ʃ2S-configured stereoisomers in the other tissues accounted for <14%. Increasing all-rac-α-tocopheryl acetate supplementation was also found to affect the 2R-configured stereoisomer profile in muscle, heart and spleen with increasing proportions of RRS-, RSR- and RSS- at the cost of RRR-α-tocopherol. In all tissues, the relative proportion of all non-RRR-stereoisomers in lambs receiving RRR-α-tocopheryl acetate was lower than RRR-α-tocopherol. These results confirm that the relative bioavailability of RRR- and all-rac-α-tocopheryl acetate is dose- and tissue-dependent and that a single ratio to discriminate the two sources cannot be used.
Introduction
Medical professionalism not only encompasses the face-to-face aspect where the doctor-patient relationship is maintained in a care manner, it goes beyond the doctor's office. During the ...COVID19 pandemic in Mexico, many doctors were attacked indicating their lack of vocation and professionalism, even though the patient had not dealt with the doctor at any time.
Objective
To analyze the perception of the professionalism of doctors by the population of the Veracruz-Boca del Río
Material and methods
A quantitative study was carried out with a non-experimental, observational, analytical and cross-sectional research design We include men and women between the ages of 20 and 70, residents of Veracruz, Mexico. A virtual survey was carried out to identify the attitudes that patients consider to be unprofessional in doctors, however, all the attitudes evaluated were actions that the doctor performs outside of his working hours or that he registers in his personal social networks.
Results
1339 subjects were included, with an average age of 33.6 (± 12.7). The use of vulgar language (30.9%), publication in social networks against feminism (36.2%) or sexual content (73.3%) is perceived as unprofessional for both sexes. Regarding female doctors, 34.5% of patients indicate as unprofessional the publication of alcohol on social networks (34.5%), being at an informal party (29.6%) or smoking tobacco (34.2%), while for a male doctor the publication in social networks of drinking alcohol (40%) or being in an informal party (36.1%) consider it unprofessional. Less than 20% of those surveyed consider their position on cannabis use, feminism or abortion, type of clothing, sedentary lifestyle, religion, age, tobacco or alcohol consumption unprofessional in their daily life.
Conclusions
The patient perceives the professionalism of the doctor from social networks in actions that are not directly related to how professional he can be when performing his work as a doctor.
Key messages
The patient perceives the professionalism of the doctor from social networks.
The patient perceives the professionalism of the doctor from social networks in actions that are not directly related to how professional he can be when performing his work as a doctor.
Aim
To assess the impact of mechanical overinstrumentation of root canals in extracted teeth on the development of dentinal microcracks in the apical portion of the root by means of micro‐computed ...tomographic (micro‐CT) analysis. Root canal preparation short of the canal terminus and at the apical foramen (AF) were used as controls.
Methodology
Twenty 2‐rooted maxillary premolars with two canals were selected, scanned in a micro‐CT device and the root canals prepared sequentially using Reciproc M‐Wire R25 instruments to working lengths: 1 mm short of the AF (AF − 1 mm), at the AF (AF), and overinstrumentation (AF + 1 mm). A micro‐CT scan of each specimen was performed after each time point. After reconstruction and co‐registration procedures, the images were screened from the cementoenamel junction to the apex (n = 55 352) to identify the presence of dentinal microcracks in the apical third of the root.
Results
After the analyses of 55 352 slices, dentinal microcracks were visualized in 12.45% of the images (6892 slices), with 5.73% (3174 slices) in the cervical, 3.57% (1976 slices) in the middle and 3.15% (1740 slices) in the apical third. All dentinal microcracks observed at all time points (AF − 1 mm, AF and AF + 1 mm) were already present in the corresponding images before canal instrumentation. Therefore, no new microcracks were detected, regardless of the working length used for canal instrumentation.
Conclusion
Reciprocating root canal preparation either short, at or beyond the AF (overinstrumentation) did not create dentinal microcracks in the roots of extracted 2‐rooted maxillary premolars.
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