Academic literature on the topic 'Gums and resins, Synthetic – Quality control'

Aim. Comparative clinical study of hygienic dental product of plant origin based -mangostin [1,3,6-Trihydroxy-7-methoxy-2,8-bis(3-methyl-2-butenyl)-9H-xanthen-9-one], a xanthone from mangosteen fruit, having antimicrobial and anti-inflammatory activity in the treatment of chronic generalized catarrhal gingivitis.
 Methods. The study included 319 patients aged 22 to 45 years. All patients were divided into two groups: the control group 20 people (males 40%, females 60%), average age 34.88.00 years; the comparison group 20 people (males 45%, females 55%), average age 35.07.10 year; the main group 20 people (males 40%, females 60%), average age 34.97.86 years. There were no statistically significant differences between all groups (p 0.05). The nosological form of the disease in the studied patients is chronic generalized catarrhal gingivitis (K05.1). Treatment in all groups was carried out using the standard regimen of complex therapy of chronic generalized catarrhal gingivitis. Therapy of the main group patients was supplemented by the use of the hygienic gel containing 1% -mangostin [1,3,6-Trihydroxy-7-methoxy-2,8-bis(3-methyl-2-butenyl)-9H-xanthen-9-one], whereas treatment of the comparison group patients was supplemented by the complex preparation containing 1% metronidazole and 0.25% chlorhexidine digluconate. The dental examination included a questionnaire with the registration of subjective data (patient complaints) and objective data on the state of the tissues of the mouth (index score) before and after therapy, as well as the dynamics of the indicators fixing during the entire treatment.
 Results. The performing a comparative study of the treatment effectiveness of chronic generalized catarrhal gingivitis, using a dental hygienic gel containing 1% -mangostin [1,3,6-Trihydroxy-7-methoxy-2,8-bis(3-methyl-2-butenyl)-9H-xanthen-9-one] as a part of complex therapy in comparison with the standard complex treatment regimen supplemented by dental product containing 1% metronidazole and 0.25% chlorhexidine digluconate, showed a marked improvement in subjective quality of life of patients. Pain during individual oral hygiene and food intake (decrease to 0%, p1 0.05, p2 0.05), a feeling of bursting in the gum (decrease to 0%, p1 0.05, p2 0.05), bad breath (decrease to 0%, p1 0.05, p2 0.05) and bleeding gums (decrease to 0%, p1 0.05, p2 0.05) were completely eliminated. Compared to the control group, OHI-S index of the main group decreased by 79% (from 1.9 to 0.4, p1 0.001, p2 0.001), PI index decreased by 80.6% (from 3.1 to 0.6, p1 0.001, p2 0.001) and SBI index decreased by 100% (from 3 to 0, p1 0.001, p2 0.001). During the course of treatment of patients with chronic generalized catarrhal gingivitis, a decrease in the average values of the PMA index was observed. In the group of patients using hygienic gel as a supplement to treatment, the decrease in this index was 85% (from 651.53 to 100.82%; p1 0.001, p2 0.05), and when using a complex drug containing 1% metronidazole and 0.25% chlorhexidine digluconate, the value of the PMA index decreased by 51% (from 611.17 to 301.4%; p1 0.001), in the control group, the index value decreased by 28% (from 671.67 to 481.26%; p1 0.001).
 Conclusion. In assessing of the subjective quality of life and index indicators of the periodontal status in the treatment of chronic generalized catarrhal gingivitis, the best results were observed in the group using a dental hygiene gel based on -mangostin [1,3,6-Trihydroxy-7-methoxy-2,8-bis(3-methyl-2-butenyl)-9H-xanthen-9-one], a xanthone from mangosteen fruit, compared with the control group and the group using a complex drug (1% metronidazole and 0.25% chlorhexidine digluconate).

Abstract The idea and experimental verification of assumptions of the integrated recycling process of matrices of uniform self-hardening moulding sands with synthetic resins, leading to obtaining moulding sands matrix of expected quality - is presented in the hereby paper. The basis of the presented process constitutes a combination of the method of forecasting averaged ignition losses of moulding sands after casting and defining the range of necessary matrix reclamation treatments in order to obtain its full recycling. Simultaneously, the empirically determined dependence of dusts amounts emitted during the reclamation process of the matrix from the given spent sand on the ignition loss values (which is the most proper assessment index of the obtained reclaimed material quality) was taken into account. The special experimental stand for investigations of the matrix recycling process was one of the elements of the conceptual approach and verification of its assumptions. The stand was equipped with the system of current on-line control of the purification degree of matrix grains from organic binder remains. The results of own investigations, allowing to combine ignition loss values of spent moulding sands after casting knocking out with amounts of dusts generated during the mechanical reclamation treatment of such sands, were utilized in the system.

Mosquitoes are the most important group of insects in terms of public health importance, which transmit serious human diseases. The continuous application of synthetic insecticides to control these mosquitoes causes development of resistance in vector species, and an adverse effect on environmental quality and non-target organisms including human health. Therefore, the use of active toxic agents from plant extracts as alternative mosquito control strategy cannot be over emphasized, as these are non-toxic, easily available at affordable prices, biodegradable and show target - specific activities against different species of vector mosquitoes. The aim of the present study was to evaluate the larvicidal efficacy of the aqueous and methanol leaf extracts of H. suaveolens against the fourth instars larvae of Anopheles species. Standard WHO protocols was adopted for the larvicidal bioassay. Larvicidal activity was evaluated at concentrations of 200, 400, 600, 800 and 1000 mg/L. The larval mortality was observed after 24 and 48hours bioassay. The results are mean of three replicates and the mortalities recorded were subjected to chi-square test and probit analysis to determine median lethal concentrations (LC50). TheGC-MS analysis ofthe methanolic leaf extract of the plantrevealed the presence of twelve compounds on the chromatogram. Among the major compounds areOleic Acid (33.33%), Octadecanoic acid (13.52%), 1,3-Cyclohexadiene-1-methanol,alpha.,2,6,6-(10.42%), 1,3-Cyclopentanediol, trans (9.60%), n-Hexadecanoic acid (9.01%) and 4-Hepten-3-one, 4-methyl (7.0%).The phytochemical screening of the aqueous and methanol leaf extracts of the plant revealed the presence of Tannins, Terpenoids, Flavonoids, Steroids, Carbohydrates, Cardiac glycoside and resins. The LC50 values estimated were 316.22mg/Lfor methanol extract and 323.59 mg/L for aqueous extract. The differences between the two extracts were however not significantly different at P>0.05. The findings also revealed that mortality was concentration dependent and both extracts showed promising larvicidal activity against Anopheles species larvae. Therefore, the crude leaf extract of the plant is recommended to be used as alternative to synthetic larvicides and further research is needed to test the activity of the plant on non-target organisms.

The operating conditions of several process vessels in the hydrometallurgical sector are so severe that engineers employ carbon steel with corrosion-resistant cladding such as titanium, zirconium and tantalum; high nickel alloy weld overlay; or the use of corrosion resistant membranes. Corrosion resistant membranes may be constructed of halogenated synthetic rubbers, vinyl ester resins, fluoropolymers, bituminous mastic, or homogeneously bonded lead. The quality and integrity of such membranes is of the utmost importance to the safe operation and 20+ years of service life for such vessels. The authors have employed a number of the above noted membranes in acid leach reactors, oxidation autoclaves, hydrogen sulfide (H2S) precipitation reactors, pressure letdown vessels, and off-gas cyclones. This paper presents an outline of the quality control activities undertaken by the authors for several recently completed and on-going hydrometallurgical projects, including prequalification, validation testing, material verification, contamination control, discontinuity (holiday) testing, non-destructive examination and assisted/enhanced visual inspection.