86 research outputs found
Unusual anatomy of maxillary central incisor with two roots
No full textIntroduction: Knowledge of root canal morphology is essential for successful endodontic therapy. Failure to recognize unusual root canal anatomy may lead to unsuccessful endodontic treatment. Case Report: This case report describes the successful endodontic treatment of the maxillary central incisor with unusual anatomy of two roots and two root canals. A 23-year-old male patient was referred for dental consultation with discoloration of the maxillary right central incisor with periapical lesion, which revealed unusual anatomy of root on radiographic examination, and was confirmed upon exploration. Discussion: As described by Vertucci, the maxillary central incisor presents a single root and single root canal in 100% of the cases. However, few cases of maxillary central incisors with two canals were reported in the literature, most of which were associated with developmental anomalies like fusion, germination or dens invaginatus. Clinician should be aware of the unusual anatomical variations that should be detected by the different diagnostic resources available
Peregrination of endodontic tools-past to present
No full textThe clinical practice of yesterday′s endodontics becomes the heresy of today, and today′s endodontic practice becomes the heresy of tomorrow. The history of endodontics begins in the 17 th century. Since then, there have been numerous advances and developments, and research has proceeded continuously without pause. The manufacture of the first instruments for endodontic use dates back to 1875. These early instruments were made by hand from thin steel wires, and they performed the function of modern barbed broaches. In 1955, Ingle was the first to express the need for standardization of canal instruments. In 1965, the American Association of Endodontists adopted the terminology and nomenclature of the proposed standardized system. For many years, the standard cutting instruments have been the reamer, the K-type file, and the Hedstroem file. Recent changes in both metallurgy and endodontic concepts have led to the introduction of a wide range of new instruments. An effort has been made here to present the journey of endodontic instruments from the past to the present
Clinical considerations in restorative dentistry - A narrative review
No full textThe relationship between periodontal health and the restoration of teeth is intimate and inseparable. Human teeth are designed in such a way that the individual tooth contributes significantly to their own support as well as collectively the teeth in the arch. Decay on the proximal surfaces occurs mainly due to the faulty interrelationship between the contact area, marginal ridge, the embrasures and the gingiva. An adequate understanding of the relationship between periodontal tissues and restorative dentistry is paramount to ensure an adequate form, function, aesthetics and comfort of the dentition. For long-term survival of restoration, both functionally and esthetically, certain biological considerations are very critical to preserve the health of the periodontium and thus must be given due importance in clinical practice. While most clinicians are aware of this important relationship, uncertainly remains regarding specific concept such as biologic width and its maintainces
Understanding the role of early-stage seed development on final seed weight by linking seed physiology, transcriptomics, and environments in soybean (Glycine max (L.) Merr.)
Get PDFSoybeans, which are widely grown in the United States, are used as food, animal feed, and industrial oil. The rise in plant-based diets highlights the high protein content and versatility of soybean. Understanding seed development is crucial for increasing yield. Soybean seed development includes three phases: lag, seed-filling, and maturation. Post-fertilization, the seed undergoes cell division in the lag phase, forming the embryo, endosperm, and seed coat. The embryo absorbs the endosperm and develops into two cotyledons. During the seed-filling phase, cotyledon cells accumulate starch, proteins, and lipids. During maturation, seeds dry out and become quiescent. Studies indicate that the lag phase significantly impacts final seed weight, yet my understanding of soybean seed development, especially its physiological and molecular aspects and environmental interactions, is limited.
I conducted growth chamber experiments where an elevated temperature shift (an 8 °C increase from control) was applied during either the lag or seed-filling phase to observe its effects on seed development. The temperature shift during seed-filling phase did not affect seed weight, but a shift during the lag phase significantly reduced seed weight. The temperature shift during the lag phase did not impact on the lag phase duration but reduced the seed-filling duration and decreased final seed weight, even when plants returned to control temperature. Further, temperature shift during lag phase reduces the number of cotyledon pavement cells indicating that the maximum potential for seed weight is set during the lag phase, and minor environmental changes during this critical period can significantly impact seed weight.
A greenhouse study using soybean cultivars with varying seed weights (two small-seeded and two large-seeded) revealed a significant positive correlation between seed weight and lag phase duration, suggesting a genetic determination of lag phase duration. Further, big-seeded cultivars had more pavement cells on the ventral cotyledon surface than small-seeded ones, implying that a longer lag phase allows for greater cell division in the cotyledons. To validate these observations, I analyzed publicly available RNA-seq data of large- and small-seeded soybeans at the cotyledon stage (final stage of the lag phase). Differential gene expression analysis identified transcripts enriched in either large- or small-seeded soybeans. Mapping these transcripts to specific seed compartments using another seed compartment-specific RNA-seq dataset revealed that seeds of the large-seeded cultivar contained transcripts encoding proteins indicative of continued cell division at the cotyledon stage, with the seed coat containing transcripts related to cell proliferation. By contrast, embryos of the small-seeded cultivar were linked to reserve accumulation processes, and their seed coats exhibited signs of lignification and maturation already at the cotyledon stage. Physiological and molecular data indicate collaborative regulation of seed growth by different seed compartments, with prolonged development in large seeds, marked by a longer lag phase, resulting in more cotyledon cells and increased size.
Next, I studied the effects of two planting dates (May and June) on seed development. Results showed shorter lag and seed-filling phases in June due to different variables like photoperiod and temperature, resulting in lower seed weight in June than in May planting. Our results also revealed that even under field conditions with different planting dates, the lag phase duration is positively correlated with seed weight. These findings highlight the significance of the lag phase in soybean seed development and yield
Biocontrol of <I>Rhizoctonia solani</I> Root Rot of Chilli by <I>Bacillus subtilis</I> formulations under Pot Conditions
No full textThe chilli crop suffers massive yield loss due to root rot caused by <em>Rhizoctonia solani</em>. An increase of 10 × 10<sup>5</sup> root colonizing units/cm was obtained as a result of <em>Bacillus subtilis</em> in vitro root colonisation assay post germination. Shelf life studies of the formulations revealed stable population level of the biocontrol agent upto 180<sup>th</sup> day (30°C - 1.6 × 10<sup>8</sup>; 4°C - 1.9 × 10<sup>8</sup>) in talc and upto 150<sup>th</sup> day in lignite (30°C - 1.5 × 10<sup>8</sup>; 4°C - 1.3 × 10<sup>8</sup>). Soil, seed, foliar spray and dip treatment methods of <em>B. subtilis</em> and chlorothalonil brought about a considerable enhancement of all biometric parameters and reduced disease incidence compared to the untreated control. In comparison to the untreated control (50 g and 21 g fresh and dry weight, respectively), highest plant fresh weight (76.84 g) and dry weight (34.17 g) was achieved by the Seed application method. Comparison of plant height revealed maximum values 70 cm (soil application) and 77 cm (dip treatment) with <em>B. subtilis</em> application which was analogous to chlorothalonil treatment (56.5 cm with soil application and 70.33 cm with dip treatment) which was considerably superior to the untreated control (58.2 cm with dip treatment and 61 cm with soil application, respectively). Root dip treatment showed considerable increase in root length with <em>B. subtilis</em> (33 cm) and chlorothalonil (28.5 cm) when compared to untreated control (15 cm). Growth promotion was better with Root dip application while disease control was achieved better with seed application. A 66% and 84% reduction in incitation of disease was noticed with soil and seed application methods, respectively.</jats:p
Optimization of adhesive joining process parameters on single lap shear strength properties of hybrid metal polymer composite joints
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BIM-based framework for circularity and environmental impact assessment during the design stage
No full textThe Circular Economy (CE) in the built environment has gained attention due to the current unsustainable linear model. There are several indicators to measure the transition towards the CE in the built environment, but no consensus has been reached. Based on previous literature, the design decisions during the preliminary stage of the design should consider circularity performance and environmental impact as key indicators. Traditionally, these assessments are performed at the end of the design stage, limiting their use for making design decisions. Hence, there is a need to develop a framework or a tool to perform the assessment during the design stage. In recent years, Building Information Modelling (BIM) has shown its potential in the construction industry. However, there is limited research on its effectiveness to enhance sustainability driven by CE.The objective of the research was divided into three parts: determine the necessary CE metrics related to product circularity performance and environmental impact during the design stage; develop a framework and a tool to conduct an assessment during the design stage and determine a method to support designers to make design decisions based on the assessment and project requirements. A framework was proposed to conduct the assessment during the design stage. A prototype in Revit using Dynamo, a visual programming platform, was developed for conducting the assessment. A multi-criteria decision making (MCDM) using the TOPSIS method was performed on the obtained assessment results for the products to make a trade-off between circularity performance and environmental impact and obtain the best alternative product for the design. A case study and workshop validate the proposed framework. The criteria for evaluation include the applicability of the framework, accuracy of the developed tool for the assessment, usability of the tool and its implication to make a balanced design choice and its contribution towards sustainability and circularity consciousness. Based on the implementation of the developed tool and workshop, it was observed that the tool can be applied to real-time projects and had the ability to support designers to make sound decisions based on circularity and sustainability criteria. It had 95 - 100% accuracy when compared to other commercial tools. During the workshop, it was perceived that over the period of time the developed tool improves the designer's consciousness on circularity and sustainability.Civil Engineering | Construction Management and Engineerin
Krein's method in inverse scattering
Get PDFA detailed discussion of the Krein’s results (applicable for solving the inverse scattering problem) is given with complete proofs. It is shown that the S-function S(k) used in Krein’s work is the S-matrix used in physics. The basic new results of the paper include the detailed description and analysis of an inversion algorithm based on Krein’s results and a proof of its consistency, that is the proof that the reconstructed potential generates the same scattering data from which it was reconstructed. Numerical advantages of using Krein’s method are discussed
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