scholarly journals Experimental justification of the maximum possible concentration (MPC) of dichlorohexafluorobutene in a working area

2021 ◽  
Author(s):  
IE Shkaeva ◽  
SA Dulov ◽  
OS Nikulina ◽  
SA Solnceva ◽  
AV Zemlyanoi
Keyword(s):  
Health Hazard ◽  
Recovery Period ◽  
Cardiac Activity ◽  
Cumulative Effect ◽  
Electron Capture Detection ◽  
Air Concentration ◽  
Hazard Class ◽  
Inhalation Study ◽  
Morphological Alterations ◽  
Study Results

To date, there have been no exposure standards for air concentrations of 1,4-dichlorohexafluorobutene (DCHF) in the work areas. The study was aimed to assess the toxicity of DCHF and to evaluate health hazard in acute, subacute, and chronic experiments. It was found that the substance was highly hazardous, DL50 in mice after intragastric injection was 79.0 mg/kg, СL50 was 229.0 mg/m3, and in rats these values were 86,0 mg/kg and 670,0 mg/m3. In animals, DCHF had a moderate local irritative effect on animal skin and ocular mucous membranes, as well as the skin resorptive effect. The 18.2 mg/m3 threshold limit concentration for a single inhalation exposure to DCHF was defined based on the changes in behavior responses and blood parameters. The 30-day subacute inhalation experiment revealed the pronounced cumulative effect of the substance. The 4-months chronic inhalation study showed that the exposure of experimental rats to 16.8 mg/m3 concentration of DCHF resulted in impaired function of central nervous system and cardiac activity, altered hematologic, biochemical, acid-base, and blood gas values, as well as in morphological alterations in lungs, which persisted after the 30-day recovery period. The chronic exposure threshold defined for DCHF was 2.2 mg/m3, and the defined no observable effect level was 0.24 mg/m3. Based on the study results, the maximum permissible concentration of DCHF in the air of the working area of 0.2 mg/m3 was confirmed and approved, the substance was assigned hazard class 2, vapor + aerosol + (specific protection of skin and eyes required). Gas chromatographic method using electron-capture detection for determination of DCHF mass air concentration in the work areas has been developed and approved.

Correction of motor coordination abilities in acute cerebral circulation defect with the use of physical rehabilitation

2020 ◽  
pp. 91-97
Author(s):  
Andrey P. Popov ◽  
Valentina I. Syutina
Keyword(s):  
Muscle Strength ◽  
Cerebral Circulation ◽  
Motor Coordination ◽  
Center Of Mass ◽  
Recovery Period ◽  
Standing Position ◽  
Physical Rehabilitation ◽  
Early Recovery ◽  
Leading Role ◽  
Study Results

Due to the high frequency of strokes in the Russian Federation, leading to disability, loss of efficiency and loss of household autonomy, the development of methods of patients rehabilitation who have suffered acute cerebral circulation disorder is of high importance. The consequences of this condition is characterized by a number of syndromes, among which the leading role in reducing the motor activity of patients and limiting their ability to self-service, is hemiparesis, accompanied by a decrease in voluntary muscle strength in the affected limbs. We present the study results of computer stabilometry indicators as a means of assessing the ability to maintain static equilibrium in a standing position and control the oscillations of the general center of mass. We also present the evaluation results of arbitrary muscle strength of the affected limbs in patients with the consequences of acute cerebral circulation defect in the early recovery period. These studies were carried out as part of an experiment to assess the effectiveness of the multisensory stimulation technique, which is based on the combination of a number of stimulating and corrective effects in combination with physical exercises in closed and open kinematic circuits. The results of the study confirm the effectiveness of the developed method of physical rehabilitation.

Determination of Important Parameters and Technical Characteristic for Welding Fumes Index Development by Using QFD Approach

2013 ◽  
Vol 315 ◽  
pp. 744-748
Author(s):  
Azian Hariri ◽  
Abdul Mutalib Leman ◽  
Mohammad Zainal M. Yusof
Keyword(s):  
Quality Function Deployment ◽  
Health Hazard ◽  
Main Idea ◽  
Workplace Safety ◽  
Technical Characteristic ◽  
Welding Fumes ◽  
System Effect ◽  
Safety And Health ◽  
Study Results

This paper discussed on the determination of important parameters and technical characteristic for the development of a welding fumes index by using Quality Function Deployment (QFD) approach. Welding fumes index is developed with the objective to enhance the welding workplace safety and health. Index simplifies complex health-hazard issues of welding fumes to be comprehended easily by the employees. Questionnaires on welder desire to know the various welding fumes health effects that exist in their workplace were distributed among welders of a selected automotive assembly lines in the state Pahang, Malaysia, during a pilot case study. Results of the questionnaires show that all the customer requirements (irritants effect, sensitizer effects, respiratory system effect, systemic toxin effect, reproductive toxins effect, carcinogen effect, mixture effect) were equally important to the welders. The relationship between the customer (welder) requirement and technical characteristic were established whereby important technical characteristics were shortlisted. Development of welding fumes index according to employees demand will increase the knowledge and awareness on occupational safety and health among employees. The paper provides the main idea on development of welding fumes index taking into consideration the needs of the customer i.e. welder.

scholarly journals A multivariate analysis of CalEnviroScreen: comparing environmental and socioeconomic stressors versus chronic disease

2017 ◽  
Author(s):  
Ben K. Greenfield ◽  
Jayant Rajan ◽  
Thomas E. McKone
Keyword(s):  
Principal Component Analysis ◽  
Environmental Protection Agency ◽  
Disease Burden ◽  
Multiple Stressors ◽  
Health Hazard ◽  
Principal Component ◽  
Component Analysis ◽  
Environmental Indicators ◽  
Spatial Autoregression ◽  
Study Results

AbstractBackgroundThe health-risk assessment paradigm is shifting from single stressor evaluation towards cumulative assessments of multiple stressors. Recent efforts to develop broad-scale public health hazard datasets provide an opportunity to develop and evaluate multiple exposure hazards in combination.MethodsWe performed a multivariate study of the spatial relationship between 12 indicators of environmental hazard, 5 indicators of socioeconomic hardship, and 3 health outcomes. Indicators were obtained from CalEnviroScreen (version 3.0), a publicly available environmental justice screening tool developed by the State of California Environmental Protection Agency. The indicators were compared to the total rate of hospitalization for 14 ICD-9 disease categories (a measure of disease burden) at the zip code tabulation area population level. We performed principal component analysis to visualize and reduce the CalEnviroScreen data and spatial autoregression to evaluate associations with disease burden.ResultsCalEnviroScreen was strongly associated with the first principal component (PC) from a principal component analysis (PCA) of all 20 variables (Spearman ρ = 0.95). In a PCA of the 12 environmental variables, two PC axes explained 43% of variance, with the first axis indicating industrial activity and air pollution, and the second associated with ground-level ozone, drinking water contamination and PM2.5. Mass of pesticides used in agriculture was poorly or negatively correlated with all other environmental indicators, and with the CalEnviroScreen calculation method, suggesting a limited ability of the method to capture agricultural exposures. In a PCA of the 5 socioeconomic variables, the first PC explained 66% of variance, representing overall socioeconomic hardship. In simultaneous autoregressive models, the first environmental and socioeconomic PCs were both significantly associated with the disease burden measure, but more model variation was explained by the socioeconomic PCs.ConclusionsThis study supports the use of CalEnviroScreen for its intended purpose of screening California regions for areas with high environmental exposure and population vulnerability. Study results further suggest a hypothesis that, compared to environmental pollutant exposure, socioeconomic status has greater impact on overall burden of disease.

scholarly journals Komunikasi Keluarga Penyintas Covid-19 di Pedesaan: (Studi Kasus Banyumas dan Cilacap)

2021 ◽  
Vol 9 (2) ◽  
pp. 97-107
Author(s):  
Agus Ganjar Runtiko ◽  
Edi Santoso
Keyword(s):  
Family Communication ◽  
Recovery Period ◽  
Psychological Trauma ◽  
Communication Patterns ◽  
Good Communication ◽  
Inhibiting Factors ◽  
Inhibiting Factor ◽  
Study Results ◽  
Initial Recovery

The Covid-19 pandemic that has lasted for more than a year has changed many things. One thing that has changed is family communication, especially one whose members have been confirmed positive for Covid-19. This study aims to determine: 1) the communication patterns of the families of covid-19 survivors; 2) the supporting and inhibiting factors in healing psychological trauma due to Covid-19; and 3) the communication patterns of the survivors before, during, and after recovering from Covid-19. The research method used is a case study conducted in Sawitan Village, Banyumas Regency, and Rikmayung Village, Cilacap Regency. The study results show that: 1) family members are the prominent supporters of communication during survivors experiencing symptoms of Covid-19, and during the initial recovery period and socializing with the community; 2) the supporting factor for healing psychological trauma is family communication with a positive tone and good communication with neighbours and the environment, while the inhibiting factor is communication avoidance, and 3) Covid-19 survivors tend to communicate more empathy with other sufferers and are more careful in carrying out health protocols.

Immediate and Long-Term Effects of Glare from following Vehicles on Target Detection in Driving Simulator

1996 ◽  
Vol 1550 (1) ◽  
pp. 16-22 ◽  
Author(s):  
Thomas A. Ranney ◽  
Anthony J. Masalonis ◽  
Lucinda A. Simmons
Keyword(s):  
Target Detection ◽  
Driving Simulator ◽  
Response Times ◽  
Recovery Period ◽  
Cumulative Effect ◽  
Laboratory Studies ◽  
Long Term Effects ◽  
Fixed Base ◽  
Episode Duration

Nine hypotheses concerning the immediate and long-term effects of glare were tested in a fixed-base truck simulator. Eight subjects completed two 4-hr sessions. During one session, simulated headlight glare from following vehicles was presented intermittently in the cab's side mirrors. Designated targets, including pedestrians and vehicles in the mirrors, were presented at the beginning, middle, end, or 5 sec following glare episodes. Response times and accuracy for detecting targets were recorded. Target detection in the presence of glare was slower than in the absence of glare. Pedestrians appearing in the middle of a glare episode were detected faster than those appearing at glare onset, indicating adaptation to glare. Target detection following a 5-sec recovery period was faster than for targets appearing immediately following the glare episode. A longer recovery period did not provide an additional benefit. Glare episode duration did not affect target-detection speed following the glare. Performance did not deteriorate over the course of the glare session, indicating no cumulative effect of glare on target detection. Overall, the impairment effects associated with glare were not as strong and consistent as in previous laboratory studies. Differences in attentional demands between laboratory studies and driving were used to explain these differences.

scholarly journals Food processing as a means for pesticide residue dissipation

2016 ◽  
Vol 31 (3-4) ◽  
pp. 89-105 ◽  
Author(s):  
Tijana Djordjevic ◽  
Rada Djurovic-Pejcev
Keyword(s):  
Food Processing ◽  
Pesticide Residues ◽  
Fruits And Vegetables ◽  
Health Hazard ◽  
Cumulative Effect ◽  
Cost Effective ◽  
Penetration Ability ◽  
Effect Of Food ◽  
Thermal Degradation Product ◽  
Processing Techniques

Pesticides are one of the major inputs used for increasing agricultural productivity of crops. However, their inadequate application may produce large quantities of residues in the environment and, once the environment is contaminated with pesticides, they may easily enter into the human food chain through plants, creating a potentially serious health hazard. Nowadays, consumers are becoming more aware of the importance of safe and high quality food products. Thus it is pertinent to explore simple, cost-effective strategies for decontaminating food from pesticides. Various food processing techniques, at industrial and/or domestical level, have been found to significantly reduce the contents of pesticide residues in most food materials. The extent of reduction varies with the nature of pesticides, type of commodity and processing steps. Pesticides, especially those with limited movement and penetration ability, can be removed with reasonable efficiency by washing, and the effectiveness of washing depends on pesticide solubility in water or in different chemical solvents. Peeling of fruit and vegetable skin can dislodge pesticide residues to varying degrees, depending on constitution of a commodity, chemical nature of the pesticide and environmental conditions. Different heat treatments (drying, pasteurization, sterilization, blanching, steaming, boiling, cooking, frying or roasting) during various food preparation and preservation processes can cause losses of pesticide residues through evaporation, co-distillation and/or thermal degradation. Product manufactures, from the simplest grain milling, through oil extraction and processing, juicing/pureeing or canning of fruits and vegetables, to complex bakery and dairy production, malting and brewing, wine making and various fermentation processes, play a role in the reduction of pesticide contents, whereby each operation involved during processing usually adds to a cumulative effect of reduction of pesticides present in the material. There is diversified information available in literature on the effect of food processing on pesticide residues which has been compiled in this article.

scholarly journals Prevalence of antibiotic-resistant Vibrio spp. in finfish sold in Tripoli fish markets, Libya

2020 ◽  
Vol 4 (08) ◽  
pp. 309-317
Author(s):  
Emad Ramadan Abodaia ◽  
Hanan Lotfi Eshamah ◽  
Hesham Taher Naas
Keyword(s):  
Antibiotic Resistance ◽  
Pathogenic Bacteria ◽  
Health Hazard ◽  
Resistance Rate ◽  
Potential Health ◽  
Antibiotic Resistant ◽  
Study Results ◽  
Potential Health Hazard ◽  
Amoxicillin Clavulanic Acid ◽  
Vibrio Spp

Background: The occurrence of Vibrio spp. in raw fish is common, especially from temperate climates regions, in both natural and farm environments, and in all kinds of fish. Whereas, limited data have been reported on antibiotic resistance strains of Vibrio spp. Aim: The main objectives of this study were to determine the prevalence of Vibrio spp. including antibiotic resistance strains in fresh finfish samples as well as evaluation of their antibiogram. Material and methods: Samples of 122 fresh finfish were purchased from two main fish markets in Tripoli, Libya. Samples were examined for the presence of Vibrio spp. and its antibiogram. Results: A total of 68 Vibrios belonging to six different species were isolated, the most predominant species were V. fluvialis 45(66.2%), followed by V. alginolyticus 10(14.7%), V. cholera 9(13.2%), V. parahemolyticus 2(2.9%), V. vulnificus and V. hollisae 1(1.5%). All of the isolates showed different degrees of resistance toward tested antibiotics. The isolates showed high resistance to cloxacillin, amoxicillin, vancomycin, amoxicillin/clavulanic acid, oxytetracyline, cephalothin, while for streptomycin the resistance rate was the lowest. Conclusion: The results demonstrated a high incidence of Vibrio spp. in raw finfish samples and this finding suggests that, fish sold in Tripoli fish markets could be a source of potential health hazard. This is because some of the isolated strains were resistant to the most popular antibiotics used in human and aquaculture treatments. Besides, study results indicated that, antibiotic resistance strains are common in raw finfish sold in both markets. Improvements in handling and processing are needed to minimize the prevalence of such pathogenic bacteria. Keywords: Vibrio spp., Finfish, Mullet, Sardine, Antibiotic Resistance.

scholarly journals Perfluoro-n-Butyl Iodide: Acute Toxicity, Subchronic Toxicity and Genotoxicity Evaluations

2004 ◽  
Vol 23 (4) ◽  
pp. 249-258 ◽  
Author(s):  
Darol E. Dodd ◽  
Gary M. Hoffman ◽  
Colin J. Hardy
Keyword(s):  
Health Hazard ◽  
Human Lymphocytes ◽  
Toxicity Tests ◽  
Nasal Discharge ◽  
Promising Alternative ◽  
Inhalation Study ◽  
Adverse Effect Level ◽  
Group A ◽  
Effect Level

Perfluoro-n-butyl iodide (PFBI) is a promising alternative to chlorofluorocarbon solvents used in aircraft ground maintenance operations and other military and commercial operations, because it cleans well, has zero ozone depletion potential, and has extremely low global warming properties. Toxicity tests were performed with PFBI to determine and evaluate its health hazard. Using standard testing guidelines (e.g., Organization for Economic Cooperation and Development [OECD]), tests included acute (4-h) and 4-week (6 h/day, 5 days/week) inhalation (nose-only) toxicity studies in rats, acute (10-min) inhalation cardiac sensitization study in dogs, in vitro chromosomal aberrations experiments in human lymphocytes, and in vitro mutagenic experiments in Salmonella typhimurium and Escherichia coli. There were no mortalities in rats ( n = 10) exposed for 4 h to 10,000 ppm PFBI, but all rats ( n = 10) died within 2 h when exposed to 20,000 ppm PFBI. The 4-h LC50 (95% confidence limits) was 14,000 ppm (13,000 ppm to 16,000 ppm). Signs (nasal discharge and labored breathing) observed in the rats exposed to 10,000 ppm returned to normal within 48 h. PFBI has the potential to cause cardiac sensitization in epinephrine-challenged dogs at 6200 ppm. A concentration of 3900 ppm was a no-observed-adverse-effect level (NOAEL) in the cardiac sensitization study. In the 4-week inhalation study (5 rats/sex/group), respiratory mucosal hypertrophy/hyperplasia was observed in rats of the 10,000-ppm group. A NOAEL of 1000 ppm was selected for the 4-week study on the basis that the mild increase in T4 observed at 1000 ppm was considered adaptive, not adverse, because of the absence of frank effects in the thyroid. In the in vitro studies, PFBI showed no evidence of either mutagenic or clastogenic activity. The toxicity profile of PFBI was compared to trifluoroiodomethane. In conclusion, the results of these studies indicate a low order of general toxicity and an absence of genotoxicity following PFBI exposure.

scholarly journals Lateral cephalometric diagnosis of asymmetry in Angle Class II subdivision compared to Class I and II

2014 ◽  
Vol 19 (4) ◽  
pp. 80-88 ◽  
Author(s):  
Aparecida Fernanda Meloti ◽  
Renata de Cássia Gonçalves ◽  
Ertty Silva ◽  
Lídia Parsekian Martins ◽  
Ary dos Santos-Pinto
Keyword(s):  
Class Ii ◽  
Diagnostic Methods ◽  
Class I ◽  
Linear Measurements ◽  
Morphological Alterations ◽  
Mandibular Asymmetry ◽  
Study Results ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

INTRODUCTION: Lateral cephalometric radiographs are traditionally required for orthodontic treatment, yet rarely used to assess asymmetries. OBJECTIVE: The objective of the present study was to use lateral cephalometric radiographs to identify existing skeletal and dentoalveolar morphological alterations in Class II subdivision and to compare them with the existing morphology in Class I and II relationship. MATERIAL AND METHODS: Ninety initial lateral cephalometric radiographs of male and female Brazilian children aged between 12 to 15 years old were randomly and proportionally divided into three groups: Group 1 (Class I), Group 2 (Class II) and Group 3 (Class II subdivision). Analysis of lateral cephalometric radiographs included angular measurements, horizontal linear measurements and two indexes of asymmetry that were prepared for this study. RESULTS: In accordance with an Index of Dental Asymmetry (IDA), greater mandibular dental asymmetry was identified in Group 3. An Index of Mandibular Asymmetry (IMA) revealed less skeletal and dental mandibular asymmetry in Group 2, greater skeletal mandibular asymmetry in Group 1, and greater mandibular dental asymmetry in Group 3. CONCLUSION: Both IDA and IMA revealed greater mandibular dental asymmetry for Group 3 in comparison to Groups 1 and 2. These results are in accordance with those found by other diagnostic methods, showing that lateral cephalometric radiography is an acceptable method to identify existing skeletal and dentoalveolar morphological alterations in malocclusions.

scholarly journals Structural and Typological Features of the Axiological Aspect of Modern Students’ Representation about Success

2019 ◽  
pp. 1-9
Author(s):  
Igor A. Alikin ◽  
Larisa V. Dovydenko ◽  
Natalia V. Lukyanchenko
Keyword(s):  
Achievement Motivation ◽  
Cumulative Effect ◽  
Correlation Factor ◽  
Social Utility ◽  
Social Significance ◽  
Technical Students ◽  
Study Results ◽  
Wide Range ◽  
Significance Levels ◽  
And Cluster Analysis

Currently, one of the leading orientations for determining the quality of life in many young minds is achieving success. The focus on success is the basis of achievement motivation, which activity is a psychological factor for economic growth, and this fact determines its high social significance. Psychologically competent provision of conditions for the productive implementation of pursuit for success implies understanding of its axiological aspect. A study of structural and typological features of the axiological aspect of modern students’ representation about success has been conducted. Respondents are 591 students of Krasnoyarsk universities. Methodology by S.A. Pakulina “Students’ Motivation to Achieve Success in University” has been applied. Data processing included descriptive statistics, correlation, factor and cluster analysis, as well as identification of significant differences. According to the study results, students’ representation of success is based on a wide range of values. At the same time, the values of interiorized (internally represented) success are of great importance for both humanitarian and technical students. The significance levels of various value aspects of success are interconnected in a positive way. The overall level of success values’ significance is determined by the cumulative effect of subjective and personal values, as well as values of social importance. In accordance with this, the strategy of developing psychological tools to help students in the productive implementation of the pursuit for success, should include formation of social interest, development of individual strategies for the implementation of social utility and skills for obtaining positive feedback in the process of achieving goals

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