Chemical Incidence Research Articles

Effect of irrigation protocols on chemical smear layer formation over the post-space dentin.

This study evaluated the effect of irrigation protocols using 95% ethanol (ET) or 1% peracetic acid (PA) prior the use of 2% chlorhexidine (CHX) compared to distilled water (DW) on the chemical smear layer (CSL) formation and incidence of open dentin tubules at the apical, medium, and cervical third of the post-space dentin. Scanning electron microscopy (SEM) and electron dispersive spectroscopy (EDS) images were used. Forty bovine roots were endodontically treated. After, post-space preparation was performed and the roots were randomized in four groups (n=10) according to the irrigation protocol: DW, CHX, CHX-ET and CHX-PA. The chemical composition of CSL and the incidence of open dentin tubules at the post-space thirds were evaluated by EDS (500× magnification) and SEM (2000× magnification) images, respectively. Data from chemical composition of CSL were descriptively analyzed, while the incidence of open dentin tubules was evaluated by scores and submitted to Kruskal-Wallis and Dunn test (p=.05). Cl, Bi, and Si were the chemical elements most found over the dentin after the irrigation with CHX and CHX-ET. Moreover, CHX and CHX-ET showed the highest incidence of CSL (p < .05), but without difference between them (p > .05), regardless of the post-space third. DW and CHX-PA showed similar incidence of CSL (p > .05). No difference on the incidence of open dentin tubules was found for any irrigation protocol and post-space third (p > .05). The use of 1% PA prior the post-space irrigation with CHX decrease the incidence of CSL. RESEARCH HIGHLIGHTS: The post-space irrigation with chlorhexidine results in the formation of chemical smear layer. Ethanol is not capable to remove the chemical smear layer. Peracetic acid is more effective to remove the chemical smear layer.

Effects of Pre-harvest Application of 1-Methylcyclopropene (1-MCP) on the Postharvest Quality of 'Cavendish' Banana (Musa cavendishii)

Several researches have been conducted to investigate the effect of 1-MCP in bananas, but inconsistencies in the results have been reported. Additionally, the effectiveness of 1-MCP is governed by various factors, such as cultivar, fruit maturity, concentration, time of exposure, and method of application. In this study, the effect of pre-harvest methods " Stalk End Immersion (SEI), bunch spraying (BS), Combination (SEIBS), and Control” of 1-MCP application was determined by observing the postharvest quality of Cavendish bananas, such as peel yellowing, sensory firmness, visual quality, weight loss, degree of shriveling, fruit finger drop, organoleptic attributes, chemical properties, and disease incidence. Results revealed that pre-harvest 1-MCP (aqueous solution dosage of 400 nL/L) application through SEI and SEI-BS methods significantly retarded the peel color change up to 7 days of storage and prolonged the banana's shelf life for up to 19 days under ambient storage conditions. SEI-BS delayed fruit softening (for 15 days) and maintained visual quality (for 19 days) compared to SEI. Fruits treated with 1-MCP through SEI-BS had lesser accumulated weight loss, lower degree of shriveling, and reduced finger drop incidence compared to BS and SEI methods conducted separately. In terms of cost efficiency, BS had lower cost compared to SEI and SEI-BS methods, while the chemical properties, organoleptic attributes, and disease incidence (crown discoloration, crown rot/mold, and banana anthracnose) failed to show any significant difference among pre-harvest methods.

UK resilience to a chemical incident

Following the deliberate chemical attacks in Salisbury last year, a review of UK resilience to chemical incidence was undertaken. The scope was not limited to deliberate attacks, related to terrorism,...

Impact of Bio-accelerated Farming against Conventional Farming System on Green Gram (Vigna radiata L.) under Rainfed Condition: Adaptive Management Enhances the Resilience to Climate Change

The field experiments was conducted at the Instructional Farm of Uttar Banga Krishi Viswavidyalaya, Pundibari, Coochbehar, West Bengal, India during 2011–2012. The objective was to assess the effect of chemical free bio-accelerated and conventional farming system on growth, yield attributes, yield, nutrients uptake, quality and microbial population of green gram. The farm is situated at 26o 19’86”N latitude and 89o23’53”E longitude at an elevation of 43.0 m above mean sea level. Results revealed that the growths, yield attributes, quality and microbial population of green gram were recorded higher in chemical free bio-accelerated compared to the conventional farming system. From the pooled data the highest yield was recorded under bio-accelerated farming (1500 kg ha−1) compared to the conventional farming system (1375 kg ha−1). The highest moisture percentage recorded under conventional farming (65.37%) than bio-accelerated farming system (63.35%). The nitrogen (50.40 and 73.88 kg ha−1), phosphorus (10.53 and 11.32 kg ha−1) and potassium (67.68 and 123.60 kg ha−1) uptake by crop was recorded highest under the conventional farming compared to bio-accelerated farming system. The application jiwanmrita recorded significantly higher number of microbial population in the soil of bio-accelerated farming than the conventional farming system. From the pooled data analysis showed 62.50 microbes in bio-accelerated and 39.75 microbes in conventional farming before sowing which increased up to 97.25 microbes and decreased to 31.94 microbes in bio-accelerated and Conventional farming system. Among the chemical free bio-accelerated farming system pest incidence was found to be lower as compared to the conventional farming system.

On the Double Nano-Coned Graphite Metasurface-Based Multiband CIC Absorber

Spectral characteristics of nano-engineered absorber comprised of nano-cone-shaped multi-layered (or cascaded) graphene metasurface (that results in graphite medium) were investigated under different chemical potentials and incidence conditions. The configuration of the proposed absorber is of the conductor-insulator-conductor (CIC) kind, wherein the top and bottom metasurfaces are identical in a pattern having the array of graphite-cones. Such three-layer CIC absorber hosts relatively thick dielectric substrate sandwiched between graphite nano-cone-based metasurfaces, in order to trap incidence electromagnetic fields. The results in respect of absorbance revealed usefulness of the proposed structure in spectral filtering in the visible and far-infrared regimes. Also, the tuning feature of absorber through altering the chemical potential of metasurfaces was highlighted.

Ethanol vapor treatment of ‘Laetitia’ plums stored under modified atmosphere

Abstract The objective of this work was to evaluate the effect of ethanol vapor during storage in modified atmosphere on the ripening and maintenance of the postharvest quality of ‘Laetitia’ plums. The plums were obtained from an orchard in the municipality of Lages, SC. The experimental design adopted was completely randomized. The treatments evaluated were ethanol vapor doses (0, 2, 4, 6 and 8 mL kg-1 of fruit). The fruits were stored at 0.5±0.2°C and 92±2% RH for 30 days. Upon their removal from storage followed by another three days in room conditions (20±5ºC and 63±2% RH), the fruits were evaluated in relation to their physical and chemical attributes, incidence and intensity of internal browning, quantification of ethanol, acetaldehyde and ethyl acetate, and the activity of enzymes peroxidase and superoxide dismutase. The application of ethanol vapor was efficient in maintaining the fruits flesh firmness, reducing the evolution of the red coloring, and resulted in greater activity of enzymes peroxidase and superoxide dismutase. However, the doses evaluated were not efficient in reducing the internal browning.

Effects of temperature on body chemical composition and incidence of deformities in juvenile tench, Tinca tinca (Actinopterygii: Cypriniformes: Cyprinidae), fed a commercial dry diet and/or natural food

Effects of temperature on body chemical composition and incidence of deformities in juvenile tench, Tinca tinca (Actinopterygii: Cypriniformes: Cyprinidae), fed a commercial dry diet and/or natural food

Timing of Chemical Thromboprophylaxis and Deep Vein Thrombosis in Major Colorectal Surgery: A Randomized Clinical Trial.

To identify the optimal timing of perioperative chemical thromboprophylaxis (CTP) and incidence of occult preoperative deep vein thrombosis (OP-DVT) in patients undergoing major colorectal surgery. There is limited Level 1 data regarding the optimal timing of CTP in major colorectal surgery and the incidence of OP-DVT remains unclear. Both issues influence the occurrence of venous thromboembolism (VTE) and may impact Medicare reimbursement because of penalties for hospital-acquired conditions. Patients undergoing major colorectal surgery underwent preoperative lower extremity venous duplex (LEVD) immediately before surgery. Those without OP-DVT were randomized to preoperative or postoperative CTP with 5000 units of subcutaneous heparin. Patients underwent repeat LEVD in the recovery room and on postoperative day 2. Outcome measures included early (48-hrs) and overall (30-days) postoperative VTE, bleeding complications, and OP-DVT. Eighteen patients (4.2%) had OP-DVT and were excluded. The randomized group included 376 patients (51.6% female) with mean age of 52.7 ± 17.6 years. No pulmonary embolism occurred. There was no significant difference in preoperative versus postoperative CTP with respect to early postoperative DVT [3/184 (1.6%) vs 5/192 (2.6%); P = 0.72], DVT at 30 days (1.6% vs 3.6%; P = 0.34) or bleeding complications requiring reoperation (0.5% vs 1.6%; P = 0.62). The risk of OP-DVT is higher than that of perioperative DVT after colorectal surgery and preoperative screening LEVD should be considered to identify and treat patients at risk for pulmonary embolism. Preoperative and postoperative CTP are equally safe in protecting against VTE. CMS should account for these factors when assigning financial disincentives for perioperative VTE. Clinicaltrials.gov #NCT01976988.

Incidence and characteristics of chemical burns

ObjectivesChemical burns can lead to serious health outcomes. Previous studies about chemical burns have been performed based on burn center data so these studies have provided limited information about the incidence of chemical burns at the national level. The aim of this study was to evaluate the incidence and characteristics of chemical burns using nationwide databases. MethodsA cohort representing the Korean population, which was established using a national health insurance database, and a nationwide workers’ compensation database were used to evaluate the incidence and characteristics of chemical burns. Characteristics of the affected body region, depth of burns, industry, task, and causative agents were analyzed from two databases. The incidence of chemical burns was calculated according to employment status. ResultsThe most common regions involving chemical burns with hospital visits were the skin followed by the eyes. For skin lesions, the hands and wrists were the most commonly affected regions. Second degree burns were the most common in terms of depth of skin lesions. The hospital visit incidence was 1.96 per 10,000 person-year in the general population. The compensated chemical burns incidence was 0.17 per 10,000 person-year. Employees and the self-employed showed a significantly increased risk of chemical burns undergoing hospital visits compared to their dependents. ConclusionChemical burns on the skin and eyes are almost equally prevalent. The working environment was associated with increased risk of chemical burns. Our results may aid in estimating the size of the problem and prioritizing prevention of chemical burns.

Effects of geochemical conditions on distribution of thyroid diseases due to iodine deficiency in seaside of Russia

Objective To assess the relationship between environmental chemical elements and incidence of thyroid diseases in the population of primorsky region in Russia, to understand the effects between iodine deficiency, iodine deficiency diseases and toxic elements (cadmium, lead, arsenic, tin) and essential elements (nickel, iron, molybdenum, zinc, selenium, iodine). Method By analyzing the project of Multi-purpose geochemical mapping (MGHK-1000), through the establishment of priority of screening indicators, the geochemical situation of seaside environment was evaluated; basic correlation analysis and logic analysis of binary type were used, combined with the ecohygiene method to evaluate the relationship between environmental chemical pollutant and incidence of thyroid diseases. Results The prevalence of thyroid disease was increased in recent years in Primorsky region. This region could be divided into 7 areas according to the total indicator of pollution, imbalance of zinc, iron, cobalt, manganese areas, excess of lead, strontium, nickel, chromium areas which could also lead to iodine deficiency. Conclusions Thyroid diseases are environmental-related diseases due to iodine deficiency, further associated with combined imbalance of trace elements and toxic elements. Key words: Iodine; Deficiency disorders; Ecological and hygienic analysis; Thyroid function; Toxic elements; Trace elements

Analysis of the Chemical Safety Facility Investment Performance in China

This paper adopts the accident incidence, the gross industry output value, the investment in safety facilities, and per capita wage of employment as the indexes to empirically analyze the investment performance of chemical safety facilities using time series data by VECM in China. The empirical results indicate that for China’s chemical industry, increasing investment fails to improve the short-term safety level significantly because of the offsetting behavior of workers. Over the long term, the offsetting behavior tends to disappear, and the chemical accident incidence can be decreased through increasing investment. Poor safety awareness among workers is one of the causes of accident incidences. The conclusions provide theoretical support for China to perfect chemical industry safety management.

Cholangiocarcinoma among offset colour proof-printing workers exposed to 1,2-dichloropropane and/or dichloromethane

ObjectivesThe present study was conducted to investigate the relationship between occupational chemical exposure and incidence of cholangiocarcinoma among workers in the offset colour proof-printing section of a small printing company...

Effect of Poultry Compost on Productivity and Quality of Beets

One characteristic of compost that might provide greater incentive for use by vegetable growers is suppression of soil-borne diseases in crops grown on compost-amended soils. The mode of action of low rates of compost on vegetable growth may include stimulation of microbial activity for suppression of soil-borne diseases, enhanced plant resistance, and improved nutrient availability. Preliminary research on beets demonstrated that higher stands and decreased loss to root rot diseases in poultry compost-amended plots contributed to marketable yields which were twice that of the control plots. This presentation will summarize research results from studies to determine if compost reduced disease severity by changing in soil microbial activity or if these products primarily improved plant growth as a result of increased nutrient availability. Three field experiments explored impact of two commercially available poultry compost products (2 to 5 T/A) and two rates of chemical fertilizer, on growth and disease incidence on beets. Soil microbial activity was estimated using an enzyme assay, and soil nitrate-N and ammonium-N concentrations were also measured, three times over the season. Results indicated that these composts act primarily through a nutrient affect to enhance beet yield. Neither compost affected microbial activity in the top 8 inches of soil. Both products had significant, opposite effects on available soil nitrogen. One product significantly increased the amount of available soil nitrogen over the season and beet yields. The different methods of production of the two poultry composts tested in this research had significant implications for potential use in either greenhouse or field systems. The effects of these composts on crop fertility and composition will be discussed.