Root canals shaped by nickel-titanium instrumentation with automated computerized numerical control systems

Background To investigate the efficacy of a nickel-titanium (NiTi) file with an automated computerized numerical control (CNC) system for root canal shaping. Methods The movement of the automated device and the insertion angle were investigated. In Experiment 1, simulated resin root canals were randomly divided into four groups (n = 20): manual downward movement using a handpiece (Group 1), vertical downward movement by CNC (Group 2), reciprocating up and down movement by CNC (Group 3), and spiral up and down movement by CNC (Group 4). In Experiment 2, five different insertion angles of the NiTi file were evaluated (n = 20). Four parameters were used to evaluate the shaping ability: change in the working length, central axis offset, curvature variation, and preparation time. Groups were compared using one-way analysis of variance (ANOVA) with significance was set at P < 0.05. Results The change in central axis position in the curved part of the root canal was found to be smaller in Group 4 than in other groups (P < 0.05). The curvature changes and preparation time of Groups 1 and 4 were significantly reduced compared with Groups 2 and 3 (P < 0.05). The variation in working length and curvature in the 5° insertion angle group was significantly smaller than in the other groups (P < 0.05). Conclusions A spiral up and down movement, controlled by the CNC machine, and 5° insertion angle, maintained original root canal shape more precisely than other methods.

Downward movement: (se) baisser ‘to fall’

This article aims to disambiguate the French verb baisser, which describes the downward movement of an entity, and to present its conceptual structure. Our approach is strongly based on the belief that the meaning of the word is conceptual, and that it reflects the world being looked at, not the real world (Honeste 1999, 2005). Our interest will focus on the locative and abstract meanings of the chosen verb, the uses of which we will study. Each use is a set formed by a predicate, defined by its arguments whose field is delimited by the predicate itself (Gross 2015). Arguments are defined using object classes. Each use is illustrated by a single sentence and a translation into Polish, the translation being a synonym of a word in another language. The type of event described by the verb will be studied, taking into account: the situation described by the verb (kinematic, dynamic, according to Desclés 2003, 2005); belonging to one of the four groups of verbs of movement, distinguished by Aurnague (2012) according to two parameters: change of location and change of elementary locative relwation; polarity (initial, median and final, according to Borillo 1998). Baisser has twelve uses (locative and abstract). Their invariant meaning is downwards movement, which is conceptualized in different ways: displacement of an entity downwards in physical space, but also as a decrease along a scale: of quantifiable value, of sound, of luminosity, intensity or quality, and finally of physical strength and of quality.

Contribution of gravity gliding in salt-bearing rift basins – a new experimental setup for simulating salt tectonics under the influence of sub-salt extension and tilting

Basin-scale salt flow and the evolution of salt structures in rift basins is mainly driven by sub- and supra-salt faulting and sedimentary loading. Crustal extension is often accompanied and followed by thermal subsidence leading to tilting of the graben flanks, which might induce an additional basinward-directed driver for salt tectonics. We designed a new experimental analogue apparatus capable of integrating the processes of sub-salt graben extension and tilting of the flanks, such that the overlapping effects on the deformation of a viscous substratum and the brittle overburden can be simulated. The presented experimental study was performed to demonstrate the main functionality of the experimental procedure and setup, demonstrating the main differences in structural evolution between conditions of pure extension, pure tilting, and extension combined with tilting. Digital image correlation of top-view stereoscopic images was applied to reveal the 3D displacement and strain patterns. The results of these experiments suggest that in salt basins affected by sub-salt extension and flank inclination, the salt flow and downward movement of overburden affects the entire flanks of the basin. Supra-salt extension occurring close to the graben centre is overprinted by the downward movement; i.e. the amount of extension is reduced or extensional faults zones are shortened. At the basin margins, thin-skinned extensional faults developed as a result of gravity gliding. A comparison with natural examples reveals that such fault zones can also be observed at the margins of many salt-bearing rift basins indicating that gravity gliding played a role in these basins.

Dissolved organic carbon vertical movement and carbon accumulation in West Siberian peatlands

Dissolved organic carbon is an additional path of carbon cycle but there is a lack of information about its distribution in peatland and rates of downward movement. We dated seven peat cores (separately the dissolved (DOC) and particulate (POC) organic carbon) from Mukhrino peatland (typical zonal oligotrophic bog) in western Siberia to assess the date distribution between those two peat fractions. Our results revealed that the DOC is younger than POC for the surface peatland layers (0–150 cm) and older for the deeper layers. The date differences increases with depth and reaches 2000–3000 years at the bottom layer (430–530 cm). In our hypothesis this date discrepancy caused by more young DOC moving to the deeper and older peat layers. The estimated average value of DOC downward movement was 0.047 ± 0.019 cm yr−1. Th oldest dates found at the lake bottom and ancient riverbed were 10 053 and 10 989 cal yr BP correspondingly. For the whole period of peatland functioning the average peat accumulation rate was estimated as 0.067 ± 0.018 cm yr−1 (0.013–0.332 cm yr−1), the carbon accumulation rate was estimated as 38.56 ± 12.21 g С m−2 yr−1 (28.46–57.91 g С m−2 yr−1).

S-Carvone Formulation Based on Granules of Organoclay to Modulate Its Losses and Phytotoxicity in Soil

Based on the effects that allelochemicals can exert over organisms, their use as alternatives to synthetic pesticides has been proposed. To this aim, it is important to understand their behavior in soils as allelochemicals can readily dissipate by different routes. In this work, novel granules based on the commercial organoclay Cloisite® 10A were prepared as a new strategy for the possible application of S-carvone as a bioherbicide, overcoming its rapid dissipation in the environment. Batch release, degradation, mobility, and phytotoxicity tests in soil were performed. Until now, the phytotoxicity of organoclay-based formulations of S-carvone in soil has not been studied. The release of S-carvone in water from the granules occurred slowly. There were no differences in the persistence of the allelochemical after its application to soil as a free compound (readily available form) or supported on granules. However, the granulated formulation reduced and delayed the leaching of S-carvone, thus controlling its downward movement in soil columns, as compared to the free S-carvone. Bioassays revealed that S-carvone supported on granules reduced the germination and aerial biomass of Lactuca sativa L. to a greater extent than the free compound. Our results demonstrated that the prepared formulation of S-carvone, based on granules of the commercial organoclay Cloisite® 10A, could be used to control transport losses, such as leaching or volatilization, increasing the bioefficacy of the allelochemical. These findings could inspire further investigations for the preparation of novel formulations of monoterpenes as potential bioherbicides.

Short-chain soluble polyphosphate fertilizers increased soil P availability and mobility by reducing P fixation in two contrasting calcareous soils

Short-chain polyphosphate fertilizers have been increasingly applied in agriculture, but little is known about the chemical behaviors of polyphosphate in soils. Herein, a cylinder experiment was carried out to investigate the influences of different P types (i.e., mono-ammonium phosphate (MAP), phosphoric acid (PA) and ammonium polyphosphate (poly-P)) and their application methods (single vs split) on the mobility and availability of P in soil through a column millimeter-scale slice cutting method; meanwhile a soil microcosm experiment (560-day) was conducted to investigate the effects of different P types on phosphorus dynamic transformation. Polyphosphate addition significantly increased P mobility. The average distance of P downward movement (81.5 mm) in soil profile in the poly-P application treatment increased by 33.6% and 81.1%, respectively, compared to the MAP and PA treatments. Different P application methods also markedly influenced phosphorus mobility. For instance, the average distance of P vertical movement in the split P application treatment was 21.2% higher than in the single application treatment, indicating that split P addition significantly increased P downward movement. Moreover, polyphosphate application decreased soil P fixation by blocking the transformation of the applied-P from labile to recalcitrant forms (HCl-P and residual-P). Overall, our findings provide meaningful information to current phosphorus fertilization practice in increasing soil P mobility and bioavailability. We suggest that polyphosphate could be regarded as an alternative P source used in agriculture, and split polyphosphate application is recommended as an effective P fertilization strategy.

Predisposing conditions for condylar sag after intraoral vertical ramus osteotomy

Intraoral vertical ramus osteotomy (IVRO) is used to treat mandibular prognathism and temporomandibular disorders. However, the improvement of temporomandibular disorders after IVRO is considered to be due to the anterior and downward movement of the mandibular condyle, which may lead to condylar sag, and in the worst case, condylar luxation. In this retrospective cohort study, we examined factors potentially associated with condylar sag. Univariate analysis indicated that condylar sag was significantly associated with the following factors: magnitude of setback (P = 0.001), less than 3 mm setback (P < 0.001), presence of temporomandibular joint (TMJ) symptoms (P = 0.002), Wilkes classification (P = 0.039), occlusal cant correction ≥ 2 mm (P = 0.018), and mandibular condyle deformation (P < 0.001). Setback magnitude (P = 0.032) and TMJ symptoms (P = 0.007) remained significant in the multivariate analysis. In the receiver operating characteristic curve, the setback magnitude cut-off value for condylar sag after IVRO was 3.25 mm. Thus, the incidence of condylar sag after IVRO is increased with a smaller setback magnitude (≤ 3.25 mm) and the presence of TMJ symptoms. These factors should be evaluated by surgeons during treatment planning for IVRO to estimate condylar sag, and it may be possible to predict the risk of condylar luxation.

A CONCEPTUAL STUDY ON GRAHANI DOSHA WITH ITS AYURVEDIC MANAGEMENT.

In Ayurveda, Grahani Dosha is one among the Mahagadas. In modern science, Grahani Dosha included into digestive disorders. It’s prevalence about 69% in current time because of faulty dietary habits, sedentary lifestyle, stress and side effects of modern drugs. This cause leads too many digestive diseases. The organ Grahani is the seat of Jatharagni (digestive fire) both are interrelated. It’s supported and nourished by the strength of Agni. Normally, it receives the in- gested food, which is retained by restraining the downward movement (Grahanati). After diges- tion it releases the food through sides of lumen to next Ashaya i.e. Pakvashaya. In abnormal conditions due to weakness of Agni, it gets vitiated and releases food in indigested form. When Agni is not proper the food will not be digested properly and this undigested food gets fermenta- tion and acts like poison in the body. It’s called Ama. Ama Utpatti leads to Grahani Dosha. Ag- nimandhya is important factor in the Samprapti of the disease Grahani Dosha. So it should be mainly treated for Agnivardhana by Drugs with Deepana (which enhances digestive power) and Pachana (digestive) qualities.

Tonic Downward Movement of Eyes and Its Eccentric Positioning in Downgaze Under General Anaesthesia

Objectives. To summarize abrupt eccentric eye positioning in downgaze following the downward movement of eyes encountered in patients undergoing ophthalmic surgeries under general anesthesia (GA) and analyze the relationship between the fluctuation in the depth of anesthesia (DOA) and eccentric eye positioning in downgaze. Subjects and Methods. Patients undergoing ophthalmic surgeries under GA without nondepolarizing muscle relaxant between January 2018-December 2019 in a tertiary-eye-care who witnessed a sudden tonic hypo-tropic movement of eyes were included in the retrospective, cross-sectional study. Results. A total of 8 patients out of 199 were enrolled in this study with an average age of 1.13±0.40years. All cases (3 pediatric cataracts, 4 strabismus, and 1 pseudophakia with posterior capsular opacification) were performed under GA with sevoflurane as an inducing agent. Downward movement was seen before the start of surgery in 4 cases and during surgery in 4 cases. Downward drift of eyes appeared tonic as the strong tug was felt in an extreme downward eccentric position. It was preceded by an eccentric upward drift of eyes following which sevoflurane concentration was increased to optimize DOA when this downward drift was encountered (mean minimal alveolar concentration/MAC 1.63±0.25). Downward movement was quick but return movement of eyes to the central position was gradual (mean 1.55±0.48minutes) when DOA was decreased (mean MAC 1.3±0.09).Conclusions. Tonic-downward movement of eyes or its eccentric positioning in downgaze is not an uncommon entity in children under GA without muscle-relaxant and fluctuations in DOA should be avoided to circumvent inadvertent complications during ocular surgery.

Study on the Relationship Between Myocardial Microcirculation Perfusion and Electrocardiogram ST Segment Depression in Patients With Hypertrophic Cardiomyopathy

Objective: To investigate the correlation between myocardial microcirculation perfusion status and the ST-segment depression(STD) in patients with hypertrophic cardiomyopathy (HCM)Method: Myocardial microcirculation perfusion of 32 patients with HCM (HCM group) and 28 healthy volunteers (control group) were examined using MCE, and the parameters including peak intensity (PI), area under the curve (AUC), rising slope (RS), and the time to peak (TTP) were analyzed. All subjects were examined by electrocardiogram, and the amplitude of downward movement of ST segment was measured. Then patients were divided into 3 groups according to the degree of downward movement of ST segment: ST1 group (0<ST≤0.1 MV); ST2 group (0.1 MV<ST≤0.2MV); ST3 group (0.2< MV<ST≤0.3 MV). At last, the relationship between myocardial microcirculation disorder and the degree of ST segment depression was explored.Results: Patents with HCM exhibit lower PI and AUC than their healthy counterparts (P < 0.001). No significant difference was found in RS and TTP between two groups (P > 0.05). ST depression was found in all the patients in the HCM group (P < 0.001). There was no significant linear correlation between PI and the degree of ST segment depression (r = -0.348). Then PI value was compared among ST1, ST2, ST3 and control group. The results showed that the PI value in both ST1 group and ST2 group differs from ST3 group (P < 0.01), while there was no significant difference between ST1 and ST2 group (P < 0.05). Conclusion: When ST depressed more than 0.20 mV, the STD is related to the decrease of microcirculation perfusion in hypertrophic myocardium.