Subcutaneous emphysema during root canal therapy: endodontic accident by sodium hypoclorite

Cervicofacial subcutaneous emphysema is defined as the abnormal introduction of air in the subcutaneous tissues of the head and neck. It is mainly caused by trauma, head and neck surgery, general anesthesia, and coughing or habitual performance of Valsalva manoeuvre. The occurrence of subcutaneous emphysema after dental treatment is rare, and diffusion of gas into the mediastinum is much rarer, especially when the procedure is a nonsurgical treatment. Presented here is a case of subcutaneous emphysema that occurred after sodium hypochlorite irrigation during endodontic treatment, and the description of its etiologies and prevention during nonsurgical endodontic treatment. Endodontic success can be essentially achieved via good debridement of a root canal, and an ideal endodontic irrigant is effective in removing the smear layer, opening the dentinal tubules, and producing a clean surface for closer obturation

REGIONAL PLANNING OF WASTEWATER REUSE FOR IRRIGATION AND RIVER REHABILITATION

With some agri-environmental restrictions, municipal wastewater can be utilized for agricultural irrigation and river rehabilitation. This paper develops a single-year planning model for a region in Israel which consists of a city and three potential wastewater consumers. The model incorporates, in one endogenous system, the economic, physical and biological relationships in the water-soil-plant environment system and its objective is to maximize the regional social welfare composed of the sum of agricultural and environmental net benefits. The model determines the optimal crop mix and the optimal allocation of the limited water and land resources among all potential users. Then, different allocation approaches from the concept of transferable utility games are applied to determine a reasonable and fair allocation of the additional net benefits which will be accepted by the players. The results support the collaboration among the economic entities and indicate economic and environmental advantages which can serve the decision-makers.Wastewater reuse, Allocation, Optimization Model, Transferable utility games, Resource /Energy Economics and Policy,

Flexibility of Various Nickel-Titanium Rotary Endodontic Files

Introduction: Nickel-titanium rotary files were originally developed to allow for greater flexibility when instrumenting root canals. The increased flexibility of nickel-titanium instruments allowed operators to negotiate canal curvatures with greater ease. File design is continually changing. Manufacturers are trying to produce files that will work more efficiently and safely. Knowing the properties of files marketed is especially important in helping to choose an appropriate file system. Current ISO standards require force measurements at a static point along the file. The purpose of this study was to evaluate the flexibility of four different nickel-titanium files at three different points along the file. Materials and Methods: Flexibility of four different nickel-titanium rotary files (EndoSequence, ProFile, Vortex, and Vortex Blue) was measured. Each file was clamped at 3mm, 5mm, or 7mm (n = 10/length/file) and a universal testing machine was used to bend the files to a maximum deflection of 4.5mm. All data were statistically analyzed by two-way analysis of variance and post-hoc Tukey test (P = 0.05) to determine any significant differences. Results: Statistically significant (P \u3c 0.05) differences were present. In general, ProFile was the stiffest, displaying the greatest force and bending moment values. Vortex Blue was significantly more flexible, with lower force needed for deflection and bending moments. Conclusion: Vortex Blue files showed greater flexibility compared with the other nickel-titanium rotary files studied

New technologies to improve root canal disinfection

Effective irrigant delivery and agitation are prerequisites to promote root canal disinfection and debris removal and improve successful endodontic treatment. This paper presents an overview of the currently available technologies to improve the cleaning of the endodontic space and their debridement efficacy. A PubMed electronic search was conducted with appropriate key words to identify the relevant literature on this topic. After retrieving the full-text articles, all the articles were reviewed and the most appropriate were included in this review. Several different systems of mechanical activation of irrigants to improve endodontic disinfection were analysed: manual agitation with gutta-percha cones, endodontic instruments or special brushes, vibrating systems activated by low-speed hand-pieces or by sonic or subsonic energy, use of ultrasonic or laser energy to mechanically activate the irrigants and apical negative pressure irrigation systems. Furthermore, this review aims to describe systems designed to improve the intracanal bacterial decontamination by a specific chemical action, such as ozone, direct laser action or light-activated disinfection. The ultrasonic activation of root canal irrigants and of sodium hypochlorite in particular still remains the gold standard to which all other systems of mechanical agitation analyzed in this article were compared. From this overview, it is evident that the use of different irrigation systems can provide several advantages in the clinical endodontic outcome and that integration of new technologies, coupled with enhanced techniques and materials, may help everyday clinical practice

Cost and benefits of intermediate water storage structures: case study of diggies in Rajasthan

Water storageWater deliveryIrrigation schedulingWater controlIrrigation canalsWatercoursesFarmsCrop productionCost benefit analysis

Connecting Carbon Capture with Oceanic Biomass Production

The climate change believed by anthropogenic emission is not isolated but tightly coupled with other issues including biodiversity loss and ocean acidification etc., and in order to prevent the potential serious impacts, both political and technological methods are being tried for greenhouse mitigation. Dimming the income sunlight by some “geoengineering” approaches currently seem ruinously expensive and technically difficult, and would not prevent the increase of greenhouse gases (GHGs) in atmosphere and ocean acidification, so capturing carbon to reduce the environmental concentration of carbon dioxide (CO2) and promoting renewable energy development for the reduction of using fossil fuels are very necessary. Biofuels derived from natural and agricultural biomass could be deployed for power production and existing transportation needs. The current economics are more favorable for conversion of edible biomass into biofuels, which could spend plenty of freshwater and farmlands, compete with food supply, and create a “carbon debt” with local ecosystem destruction by deforestation to expand biofuel-crop production. So it is vital to develop processes for converting non-edible feedstock such as lignocellulose and microalgae into biofuels.
 Compared with lignocellulose, microalgae have higher growth rates, don’t need plenteous freshwater for irrigating, and can grow in the conditions that are not favorable for terrestrial biomass growth. The current limitation of microalgal biofuels is the microalgae cultivation cost, and to compensate the high cost of microalgal biofuels, three suggestions are propounded here. (i) Using ships as the platforms of cultivating microalgae, producing biofuels, and transporting feedstock and products on a large scale on subtropical oligotrophic oceans, where the ocean’s least productive waters are formed with compared peaceful surface condition and poor marine communities. (ii) Operating different kinds of oceanic biomass productions for high-value products to compensate the cost of microalgal biofuels. Different kinds of microalgae and macroalgae (seaweeds) could be cultivated for biofuels, chemicals, healthy food, and feed for breeding economic marine species to satisfy the accelerating demands for seafood supply and simultaneously mitigate the fast decline of wild stocks. (iii) Constituting financial subsidies to make CO2 as the feedstock of microalgae cultivation for free, and exact quantifying the carbon captured in biomass products and the CO2 reduction that these products would provide by displacing natural and nonrenewable carbon resources, to take part in the international carbon-credit trading markets and sell the offsets. In a word, this article mainly talks about trying to find a way that connect CO2 capture with renewable energy development, and partially combat against deforestation, loss of biodiversity, shortage of food, and decline of marine lives etc., if possible

System and climate related pythium problems in mobile chrysanthemum growing systems

One Dutch greenhouse company started to grow chrysanthemums in a mobile system. The system’s basic unit is a sub-irrigated V-shaped gully of 8.0 m long and 5 cm wide, filled with a peat-coir mix. The system is hampered by growth differences along the length profile of the gullies and Pythium related yield reductions of up to 10% during the summer period. A series of experiments aimed to mimic the problems, explain causes and to advice on improvements. A Pythium ultimum pathogen from the grower was cultured in the laboratory and disseminated in the irrigation water tanks. In part of the cultivations the plants were subjected to high temperature and low air humidity treatments aimed at creating stress and Pythium susceptibility. Various plugs fit for transporting rooted chrysanthemum cuttings were tested as well. The results show that Pythium ultimum is initially the result of a too high water content in the first 10 days of the propagation phase. This was a direct consequence of precipitation of pure water by the mist system used to keep the relative humidity high. A related factor was a too low EC o

Agua y Suero Fisiológico para Prevenir la Formación de Paracloroanilina

Indexación: Web of Science; Scielo.ABSTRACT: This study determined if p-chloroaniline (PCA) can be minimized by using distilled water and physiological saline solution following sodium hypochlorite but before chlorhexidine. Hypochlorite 5%, 0.5%, 0.05%, 0.005% and 0.0005% dissolved in 0.9% NaCl and in distilled water were mixed with 2% chlorhexidine for the formation of PCA. The PCA was determined using UV-VISIBLE spectrometry, with spectral curve was determined the wavelength of maximum absorption of PCA. Formed PCA absorbance was measured between 0.025%, 0.02%, 0.015%, 0.01%, 0.005% and 0.0025% hypochlorite and 2% chlorhexidine. 2% chlorhexidine and hypochlorite with physiological saline form a white precipitate which prevents the measurement of PCA. Colored PCA is formed with 0.05%, 0.005% hypochlorite aqueous dilutions and 2% chlorhexidine. The lwavelength of maximum absorption obtained was 470 nm and absorbance of PCA showed a linear decrease. 0.005% NaClO produces the least amount of PCA. The best solvent to prevent the formation of PCA during the interaction of sodium hypochlorite with chlorhexidine is distilled water.Este estudio determinó si la p-cloroanilina (PCA) puede ser minimizada mediante el uso de agua destilada y solución salina fisiológica seguido de la aplicación de hipoclorito de sodio, previo a la aplicación de clorhexidina. Hipoclorito al 5%, 0,5%, 0,05%, 0,005% y 0,0005% fue disuelto en 0,9% de NaCl y en agua destilada se mezcló con 2% de clorhexidina para la formación de PCA. El PCA se determinó mediante espectrometría UV-Visible, y con curva espectral se determinó la longitud de onda máxima del PCA. La absorbancia del PCA formado se midió con 0,025%, 0,02%, 0,015%, 0,01%, 0,005% y 0,0025% de hipoclorito y 2% de clorhexidina. La combinación de 2% de clorhexidina e hipoclorito en solución salina fisiológica forman un precipitado blanco que impide la medición del PCA. El PCA coloreado es formado con 0,05%, 0,005% diluciones acuosas de hipoclorito y 2% de clorhexidina. La longitud de onda máxima obtenida fue de 470 nm y la absorbancia del PCA mostró una disminución lineal. NaClO al 0,005% produce menor cantidad de PCA. El mejor disolvente para evitar la formación de PCA durante la interacción de hipoclorito de sodio con clorhexidina es agua destilada.http://ref.scielo.org/2kpw6