scholarly journals CHEMICAL CHARACTERIZATION OF ASBESTOS BODY CORES BY ELECTRON MICROPROBE ANALYSIS

1972 ◽  
Vol 20 (9) ◽  
pp. 723-734 ◽  
Author(s):  
ARTHUR M. LANGER ◽  
IVAN B. RUBIN ◽  
IRVING J. SELIKOFF

Inhalation of asbestos may be associated with increased risk of developing malignant neoplasms. Some of the fibers become coated in the lung, resulting in "asbestos bodies." The occurrence of structures with the appearance of asbestos bodies in the lungs of urban dwellers the world over, individuals with no known exposure to these mineral fibers, has raised the question of whether the community at large may also have increased risk of neoplasia as the result of chance environmental asbestos exposure. Since other fibrous materials may also sometimes become so coated, epidemiology evaluation of the presence of asbestos bodies has been hampered by difficulties in obtaining absolute identification of the cores of the bodies found. Five fibrous silicates, consisting of four amphiboles (amosite, anthophyllite, crocidolite and tremolite) and one serpentine (chrysotile), constitute the asbestos mineral group. Chemically, they are diverse enough for unique identification. The electron microprobe analyzer permits microchemical analysis of particles in the sublight microscopic size range. Analysis of asbestos body cores requires particle selection, extraction from tissue matrix, a suitable conducting substrate, proper coating material, selection of optimal instrumental operating conditions and comparison of unknown cores with known fiber standards. In this investigation, asbestos body cores have been analyzed from tissues obtained from occupationally exposed individuals (known fiber exposure), laboratory animals (known exposure) and individuals with no known occupational exposure. Cores of bodies have been analyzed as amosite, chrysotile, chemically degraded chrysotile and cores of undetermined nature. Amosite fibers as cores of asbestos bodies show no marked chemical degradation even after prolonged biologic residence, whereas chrysotile asbestos cores are markedly degraded. Cores of asbestos bodies from the general population, from individuals with no known exposure, may consist of degraded chrysotile, synthetic silicate fibers and, in some cases, amphibole asbestos.

2020 ◽  
Vol 89 ◽  
pp. 65-74
Author(s):  
A. G. Zavorotnyy ◽  

Introduction. Operation of radiation hazardous facilities is a reality of the modern world, and the future of the world economy is impossible without the development of nuclear and radiation technologies. At the same time, the widespread use of atomic energy puts forward an important and responsible task of ensuring the safety of the population and the environment in conditions of an increased risk of exposure to ionizing radiation and radioactive substances. In accordance with clause 3.2.1 of the "Radiation Safety Standards NRB-99/2009", the planned increased exposure of persons involved in emergency rescue operations related to the elimination of the consequences of radiation accidents is allowed for men, as a rule, over 30 years old only with their voluntary written consent, after informing about possible radiation doses and health risks. Increased exposure refers to exposure in excess of the basic dose limits under controlled (normal) operating conditions of radiation sources. Goals and objectives. The aim of the study is to increase the functionality of emergency services and fire and rescue subdivisions to perform tasks as intended in the elimination of radiation accidents. The tasks include the construction and substantiation of a model that allows converting the risks of deterministic effects into stochastic effects risks. Methods. When calculating the probability of output of stochastic and deterministic effects depending on the radiation dose and developing a threshold quadratic model, the least squares method and the probabilistic-statistical method were used. Results and discussion. The article shows that a linear non-threshold model of the interaction of radiation with matter greatly overestimates the risk of a stochastic effect emerging at doses of radiation. For example, this overestimation is 8,13 at a dose of D = 0,2 Sv/year. In this regard, a threshold quadratic model has been developed and proposed to be replaced by a threshold quadratic model, which makes it possible to increase the planned irradiation of personnel of emergency services and fire and rescue units during the elimination of radiation accidents in an effective dose from 0,2 Sv to 0,57 Sv, moreover, the probability of emergence of stochastic effects P2 = 0,0084 remains the same for both models. Conclusions. An increase in the maximum permissible dose of radiation for personnel of emergency services and fire and rescue units from 0,2 Sv/year to 0,5 Sv/year will make it possible to increase the functionality of the emergency services and fire and rescue units to perform tasks as intended by 2,5 times when elimination of radiation accidents. For example, the scope of rescue operations may be increased from 100 %, performed at a dose of D = 0,2 Sv/year, to 250 %, performed at a dose of D = 0,5 Sv/year. Key words: emergency services, fire and rescue units, radiation accidents, irradiation, linear no-threshold model, threshold quadratic model.


2020 ◽  
Vol 17 (7) ◽  
pp. 768-779
Author(s):  
Natarajan Narayanan ◽  
Vasudevan Mangottiri ◽  
Kiruba Narayanan

Microbial Fuel Cells (MFCs) offer a sustainable solution for alternative energy production by employing microorganisms as catalysts for direct conversion of chemical energy of feedstock into electricity. Electricity from urine (urine-tricity) using MFCs is a promising cost-effective technology capable of serving multipurpose benefits - generation of electricity, waste alleviation, resource recovery and disinfection. As an abundant waste product from human and animal origin with high nutritional values, urine is considered to be a potential source for extraction of alternative energy in the coming days. However, developments to improve power generation from urine-fed MFCs at reasonable scales still face many challenges such as non-availability of sustainable materials, cathodic limitations, and low power density. The aim of this paper was to critically evaluate the state-of-the-art research and developments in urine-fed MFCs over the past decade (2008-2018) in terms of their construction (material selection and configuration), modes of operation (batch, continuous, cascade, etc.) and performance (power generation, nutrient recovery and waste treatment). This review identifies the preference for sources of urine for MFC application from human beings, cows and elephants. Among these, human urine-fed MFCs offer a variety of applications to practice in the real-world scenario. One key observation is that, effective disinfection can be achieved by optimizing the operating conditions and MFC configurations without compromising on performance. In essence, this review demarcates the scope of enhancing the reuse potential of urine for renewable energy generation and simultaneously achieving resource recovery.


2021 ◽  
Author(s):  
M. C. Frühwald ◽  
K. Nemes ◽  
H. Boztug ◽  
M. C. A. Cornips ◽  
D. G. Evans ◽  
...  

AbstractThe rhabdoid tumor (RT) predisposition syndromes 1 and 2 (RTPS1 and 2) are rare genetic conditions rendering young children vulnerable to an increased risk of RT, malignant neoplasms affecting the kidney, miscellaneous soft-part tissues, the liver and the central nervous system (Atypical Teratoid Rhabdoid Tumors, ATRT). Both, RTPS1&2 are due to pathogenic variants (PV) in genes encoding constituents of the BAF chromatin remodeling complex, i.e. SMARCB1 (RTPS1) and SMARCA4 (RTPS2). In contrast to other genetic disorders related to PVs in SMARCB1 and SMARCA4 such as Coffin-Siris Syndrome, RTPS1&2 are characterized by a predominance of truncating PVs, terminating transcription thus explaining a specific cancer risk. The penetrance of RTPS1 early in life is high and associated with a poor survival. However, few unaffected carriers may be encountered. Beyond RT, the tumor spectrum may be larger than initially suspected, and cancer surveillance offered to unaffected carriers (siblings or parents) and long-term survivors of RT is still a matter of discussion. RTPS2 exposes female carriers to an ill-defined risk of small cell carcinoma of the ovaries, hypercalcemic type (SCCOHT), which may appear in prepubertal females. RT surveillance protocols for these rare families have not been established. To address unresolved issues in the care of individuals with RTPS and to propose appropriate surveillance guidelines in childhood, the SIOPe Host Genome working group invited pediatric oncologists and geneticists to contribute to an expert meeting. The current manuscript summarizes conclusions of the panel discussion, including consented statements as well as non-evidence-based proposals for validation in the future.


2017 ◽  
Vol 46 (3) ◽  
pp. 331-339 ◽  
Author(s):  
Olli Pietiläinen ◽  
Mikko Laaksonen ◽  
Eero Lahelma ◽  
Aino Salonsalmi ◽  
Ossi Rahkonen

Aims: This study aimed to investigate whether hospitalisation is associated with increased risk of disability retirement differently across four occupational classes. Methods: 170,510 employees of the City of Helsinki, Finland were followed from 1990 to 2013 using national registers for hospitalisations and disability retirement. Increases in the risk of disability retirement after hospitalisation for any cause, cardiovascular diseases, musculoskeletal disorders, mental disorders, malignant neoplasms, respiratory diseases and injuries were assessed across four occupational classes: professional, semi-professional, routine non-manual and manual, using competing risks models. Results: In general, hospitalisation showed a slightly more increased risk of disability retirement in the lower ranking occupational classes. Hospitalisation among women for mental disorders showed a more increased risk in the professional class (hazard ratio 14.73, 95% confidence interval 12.67 to 17.12) compared to the routine manual class (hazard ratio 7.27, 95% confidence interval 6.60 to 8.02). Occupational class differences were similar for men and women. The risk of disability retirement among women increased most in the routine non-manual class after hospitalisation for musculoskeletal disorders and injuries, and most in the professional class after hospitalisation for cardiovascular diseases. The corresponding risks among men increased most in the two lowest ranking classes after hospitalisation for injuries. Conclusions: Ill-health as measured by hospitalisation affected disability retirement in four occupational classes differently, and the effects also varied by the diagnostic group of hospitalisation. Interventions that tackle work disability should consider the impact of ill-health on functioning while taking into account working conditions in each occupational class.


1995 ◽  
Vol 32 (03) ◽  
pp. 231-243
Author(s):  
Todd Schauer ◽  
Barry Romberg ◽  
Changben Jiang ◽  
Armin W. Troesch

This paper describes a means by which the capsize risk associated with various fishing vessel operating conditions can be evaluated. Rather than relying on the static restoring moment curve as the primary criteria for vessel safety, modern nonlinear systems analysis is applied to the problem of extreme nonlinear rolling in random beam sea. While the method is quite general and not limited to small vessels, it is illustrated with a specific application involving Native American trap net fishing on the upper Great Lakes. General trap net operations, as practiced by Native American fishermen and women in the Grand Traverse Bay region, are presented in detail. The most significant characteristic of trap net operations is the heel induced during net deployment and net lifting. The increased risk to the vessel, in terms of the increased probability of capsize is quantified for various heel angles and various sea states. A significant advantage of the capsize analysis method presented here is its ability to investigate quickly the effects of many parameters (e.g., trap net line tension, wave height, and/or wave period) on a nonlinear dynamic system without having to resort to extensive simulation studies.


1986 ◽  
Vol 39 (9) ◽  
pp. 1345-1349 ◽  
Author(s):  
Dell K. Allen ◽  
W. Van Twelves

The importance of computer-aided design (CAD) has not been fully appreciated as it relates to computer integrated manufacturing (CIM). The CAD product definition model can provide essential information for many down-stream production, estimating, tooling, and quality assurance functions in the CIM environment. However, the product definition model may be inaccurate or incomplete, thus causing incomplete communication with possible scrap, re-work, and missed production deadlines. Other problems are related to the fact that many of our expert designers are retiring and taking their expertise with them. Merely being able to make 2D or 3D drawings on a CAD workstation does not make its operator a designer. A knowledge of production processes, tolerances, surface finish, and material selection is needed to supplement a designers knowledge of user needs, product functional requirements, operating conditions, cost, quality, and reliability targets. One of the most promising methods for providing timely and accurate information to the designer on an “as-needed” basis is through the use of expert design systems. Such systems promise to bridge the knowledge gap between CAD and CAM and help to incorporate these functions into the overall CIM environment.


2015 ◽  
Vol 63 (2) ◽  
pp. 196-201 ◽  
Author(s):  
Natasha M. Archer ◽  
Renata Parada Amorim ◽  
Rafaela Naves ◽  
Simone Hettmer ◽  
Lisa R. Diller ◽  
...  

Hematology ◽  
2016 ◽  
Vol 2016 (1) ◽  
pp. 323-330 ◽  
Author(s):  
Flora E. van Leeuwen ◽  
Andrea K. Ng

Abstract Long-term survivors of Hodgkin lymphoma (HL) experience several late adverse effects of treatment, with second malignant neoplasms (SMNs) and cardiovascular diseases (CVDs) being the leading causes of death in these patients. Other late effects have also been identified, such as pulmonary dysfunction, endocrinopathies (thyroid dysfunction, infertility), neck muscle atrophy, and persistent fatigue. HL survivors have two- to fourfold increased risks to develop SMNs and CVD compared with the general population. With respect to SMNs, radiotherapy is associated with 1.5- to 15-fold increased risk of solid malignancies. The relative risk (RR) of solid tumors increases steadily with increasing follow-up time from 5 to 15 years since radiotherapy, and remains elevated for at least 40 years. The RR of solid SMNs increases strongly with younger age at first treatment. Risks of lung, breast, and gastrointestinal (GI) cancers increase with higher radiation dose. Alkylating agent chemotherapy, especially procarbazine, does not only increase risk of leukemia but also of solid malignancies, in particular, cancers of the lung and GI tract. In contrast, gonadotoxic chemotherapy decreases the risk of radiation-associated breast cancer, through induction of premature menopause. Smoking appears to multiply the radiation- and chemotherapy-associated risks of lung cancer. Both radiotherapy and chemotherapy for HL may cause cardiovascular toxicity. Radiotherapy increases the risk of coronary heart disease, valvular heart disease, congestive heart failure (HF), and pericarditis, whereas anthracycline-containing chemotherapy increases the risks of HF and valvular heart disease. Cardiovascular toxicity following radiotherapy is usually observed from 5 to at least 35 years after therapy, whereas anthracycline-related toxicity is already observed during treatment, up to at least 25 years. The joint effects of anthracyclines, radiotherapy, and conventional cardiovascular risk factors (eg, hypertension, smoking, and physical inactivity) appear to be additive rather than multiplicative. HL survivors need lifelong risk-based screening for selected SMNs and CVDs. Furthermore, preventive strategies should include lifestyle and drug-based interventions to minimize exposure to conventional risk factors for cancer and CVD.


Author(s):  
A. V. Nikitin ◽  
G. V. Volynets

Sclerosing cholangitis is one of the most common hepatologic extraintestinal manifestations of inflammatory bowel disease. The article discusses the phenotype of the combination of sclerosing cholangitis and inflammatory bowel disease. The authors present their theories of the etiopathogenesis of sclerosing cholangitis in patients with inflammatory bowel disease, as well as some features of the phenotype of both mixed and monogenic forms of diseases.Sclerosing cholangitis in combination with inflammatory bowel disease is commonly associated with pancolitis, but the endoscopically visualized activity of inflammatory bowel diseases is significantly lower and clinical symptoms are less pronounced. The authors have established that the patients with the combination of sclerosing cholangitis and inflammatory bowel disease are at the increased risk of developing malignant neoplasms. The formation mechanisms of a combination of inflammatory bowel disease and sclerosing cholangitis remain poorly understood, although this pathology is influenced by lymphocytic cross-reactivity, aberrant recognition of microbiotic epitopes and intestinal microbiota imbalance. New biological agents aimed at correcting the interaction between the immune system and target organs may provide new ways of treatment for sclerosing cholangitis associated with inflammatory bowel disease.


2021 ◽  
Vol 11 (21) ◽  
pp. 10350
Author(s):  
Didier Haillot ◽  
Yasmine Lalau ◽  
Erwin Franquet ◽  
Sacha Rigal ◽  
Frederic Jay ◽  
...  

The industrial sector is increasingly obliged to reduce its energy consumption and greenhouse gases emissions to contribute to the world organizations’ targets in energy transition. An energy efficiency solution lies in the development of thermal energy storage systems, which are notably lacking in the low-temperature range (50–85 °C), for applications such as district heating or low-temperature waste heat recovery. This work aims to bring a latent heat storage solution from material selection to prototype evaluation. The first part of this paper is dedicated to the characterization and aging of a phase change material selected from a screening of the literature (fatty acid mixture mainly composed by stearic and palmitic acid). Then, this material is encapsulated and tested in a prototype whose performances are evaluated under various operating conditions. Finally, a numerical model validated by the experimental results is used to explore the influence of a wider range of operating conditions, dimensioning choices, and material conductivity improvements.


Sign in / Sign up

Export Citation Format

Share Document