RESUMEN
In recent years, about 370 million tonnes of waste plastic are generated annually with about 9 % recycled, 80 % landfilled and 11 % converted to energy. As recycling of waste plastics are quite expensive and labour-intensive, the focus has now been shifted towards converting waste plastics into energy products. Pyrolysis of waste plastic generates liquid oil (crude), gas, char and wax among which liquid oil is the most valuable product. In this review, emphasis has been given on the pyrolysis products yield from both thermal and catalytic pyrolysis and the factors that affect pyrolysis products yield. The use of homogenous catalysts, for example AlCl3, can significantly improve the quality of waste plastic pyrolytic oil (WPPO), reduce time and energy consumption of the process, and help remove the contaminants of waste plastic. This study also thoroughly reviewed physico-chemical properties of WPPO to understand their thermal stability, elemental composition, and functional groups. Although liquid oil exhibits comparable heating value with commercial fuel (diesel/petrol), for example higher heating value of Polypropylene (PP) and Polyethylene (PE) are 50 and 42 MJ/kg which is between 42 and 46 MJ/kg for commercial diesel the other properties depend on several parameters such as plastic and pyrolysis reactor types, temperature, feed size, reaction time, heating rate and catalysts. A techno-economic analysis indicate that the liquid oil production cost could be about 0.6 USD/l if plant capacity is ≥175,000 million litres/year with a breakeven of 1 year. After-treatment of WPPO through distillation and hydrotreatment is recommended for improving the physio-chemical properties comparable to commercial fuel to use in automobile applications. This paper will be a valuable guide for stakeholders, and decision and policy makers for proper utilization of waste plastics.
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Plásticos , Pirólisis , Plásticos/química , Polipropilenos , Polietileno , AceitesRESUMEN
Peri-implantitis is an inflammatory disease affecting soft and hard tissues surrounding dental implants. As the global number of individuals that undergo restorative therapy through dental implants increases, peri-implantitis is considered as a major and growing problem in dentistry. A randomly selected sample of 588 patients who all had received implant-supported therapy 9 y earlier was clinically and radiographically examined. Prevalence of peri-implantitis was assessed and risk indicators were identified by multilevel regression analysis. Forty-five percent of all patients presented with peri-implantitis (bleeding on probing/suppuration and bone loss >0.5 mm). Moderate/severe peri-implantitis (bleeding on probing/suppuration and bone loss >2 mm) was diagnosed in 14.5%. Patients with periodontitis and with ≥4 implants, as well as implants of certain brands and prosthetic therapy delivered by general practitioners, exhibited higher odds ratios for moderate/severe peri-implantitis. Similarly, higher odds ratios were identified for implants installed in the mandible and with crown restoration margins positioned ≤1.5 mm from the crestal bone at baseline. It is suggested that peri-implantitis is a common condition and that several patient- and implant-related factors influence the risk for moderate/severe peri-implantitis (ClinicalTrials.gov NCT01825772).
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Implantes Dentales/estadística & datos numéricos , Periimplantitis/epidemiología , Anciano , Pérdida de Hueso Alveolar/epidemiología , Estudios Transversales , Coronas/estadística & datos numéricos , Implantes Dentales de Diente Único/estadística & datos numéricos , Diseño de Prótesis Dental/estadística & datos numéricos , Prótesis Dental de Soporte Implantado/estadística & datos numéricos , Femenino , Estudios de Seguimiento , Odontología General/estadística & datos numéricos , Humanos , Masculino , Mandíbula/cirugía , Persona de Mediana Edad , Índice Periodontal , Prevalencia , Estudios Retrospectivos , Factores de Riesgo , Estomatitis/epidemiología , Suecia/epidemiología , Resultado del TratamientoRESUMEN
The aim of the study was to examine aluminium welders for central nervous changes due to the exposure to aluminium containing welding fumes. A group of 44 aluminium welders in the train body and truck trailer construction industry (mean age: 43 years) with an average of 11.4 years of occupational exposure to aluminium welding fumes and a control group of 37 production workers (mean age: 40 years) of the same plants participated in this longitudinal study. Medical and neuropsychological examinations were performed in 1999 and 2001. Performance was measured with computerised (EURO-NES, motor performance, simple reaction time) and non-computerised test systems (verbal intelligence, standard progressive matrices, trail making, block design) and symptoms with a modified version of the questionnaire Q16. Data was analysed by multivariate analysis of variance including age, education, and alcohol marker as covariates (MANCOVA). The pre-/postshift average Al-urine concentrations of welders were in the range of 130-153µg/l. Welders showed significantly poorer performance in symbol-digit substitution, block design, and to some extent in switching attention. However, motor performance and other measures did not differ between welders and controls. Summing up, the results give no clear hints on neurological changes in Al-welders.
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A gene (rtr-1) coding for the tRNAArgACG has been isolated and characterized from the nematode, Caenorhabditis elegans. The coding portion is not interrupted by an intron and is followed by a track of four thymidines associated with termination by RNA polymerase III. The predicted mature product is 76 nucleotides (nt) long including the CCA tail, and is specific for the most used Arg codon in C. elegans. The gene can be transcribed and processed in a homologous in vitro system. The 82-nt primary transcript begins at the first purine upstream from the mature tRNA 5' end and terminates after the first thymidine of the terminator signal.
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Caenorhabditis/genética , Expresión Génica , ARN de Transferencia de Arginina/genética , Animales , Secuencia de Bases , Clonación Molecular , Datos de Secuencia Molecular , Conformación de Ácido Nucleico , Mapeo Restrictivo , Transcripción GenéticaRESUMEN
Crude fiber analysis does not accurately reflect the amount of dietary fiber in food materials, nor does it give a constant fraction of dietary fiber when used to compare sources in the diet. More accurate methods of estimating dietary fiber are compared. The neutral detergent method of Van Soest, modified for use with foods, was especially useful in measuring the insoluble fraction of dietary fiber. It not only provided a simple, quick method of analysis but also was useful in isolating dietary fiber for further experimentation. Water-holding capacity studies, trace mineral binding studies, and bile acid binding studies were run on the insoluble dietary fiber without interference from digestible food constituents.
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Celulosa/análisis , Fibras de la Dieta/análisis , Análisis de los Alimentos , Digestión , Métodos , Solubilidad , AguaRESUMEN
The Arizona Health Care Cost Containment System (AHCCCS) is an HMO-oriented Medicaid demonstration project serving approximately 170,000 persons throughout the State of Arizona. To assure that its members are receiving high quality care and because of the potentially adverse incentives of capitation, AHCCCS places particular emphasis on quality-of-care review. A key component of that review is the development of annual, statewide medical audits. In this article, we describe the nature and organization of medical care delivery under AHCCCS, outline the evolution of the annual medical audits, describe the most recent of these audits, and present and discuss the results.
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Sistemas Prepagos de Salud/normas , Medicaid/organización & administración , Auditoría Médica/métodos , Calidad de la Atención de Salud , Arizona , Control de Costos , Recolección de Datos , Estudios de Evaluación como Asunto , Proyectos Piloto , Estadística como AsuntoAsunto(s)
Fenómenos Fisiológicos de la Nutrición , Adulto , Animales , Dieta , Femenino , Alimentos/efectos adversos , Análisis de los Alimentos , Humanos , Enfermedades Intestinales/metabolismo , Lipoproteínas HDL/farmacología , Masculino , Persona de Mediana Edad , Obesidad/dietoterapia , Ratas , Zinc/análisisRESUMEN
BACKGROUND AND PURPOSE: For CT scan planning, scan projection radiographs (SPR) are used. Tube tension and current for head SPR can be reduced to a minimum because of the small head diameter and because only high-contrast structures need to be visualized for planning. The goal of this study was to investigate SPR of the head in respect to effective doses, the influence of dose-reduction measures, and comparison with conventional x-ray. MATERIALS AND METHODS: Entrance doses for default and minimal settings were measured on a LightSpeed Ultra CT scanner and on conventional x-ray equipment. Effective doses for different scanning fields of the head were calculated for an adult, a 10-year-old child, and a neonate by using the commercially available software PCXMC. RESULTS: Depending on projection and technique, SPR effective doses for adults were 1.9-27.7 muSv; for the 10-year-old child, 2.1-31.1 muSv; and for the neonate, 5.2-97.2 muSv. Doses with the tube under the table were 1.3-3.4 times lower. Doses for conventional radiography were higher than SPR doses for adults and partially lower for children. CONCLUSIONS: Depending on the scanning technique, effective doses for head SPR can differ up to 17-fold. The dose is significantly reduced by lowering tube voltage and current, by positioning the tube under the table, and by keeping the thyroid out of the scan or by protecting it with a lead collar. Compared with the conventional x-ray technique, SPR doses tend to be lower due to x-ray beam characteristics.
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Carga Corporal (Radioterapia) , Cabeza/diagnóstico por imagen , Modelos Biológicos , Dosis de Radiación , Radiometría/métodos , Adulto , Simulación por Computador , Humanos , Método de Montecarlo , Radiografía , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
The morphology of the antennal hair-sensilla of Periplaneta americana, their distribution and frequency on the antennal flagellum have been examined by transmission- and scanning-electron microscopy. The types of sensilla were distinguished with respect to physiologically relevant criteria such as wall structure and number of sensory cells. Among the sensilla of the antenna of the adult male, long, single-walled sensilla with four sensory cells (types sw B), Probably responsible for reception of sexual pheromones, are most frequent, representing about 54% of the antennal sensilla. About half of these sensilla are newly-formed at the imaginal ecdysis; the other half are derived from the shorter type sw B sensilla of the nymphal antenna. Short type sw B sensilla are present in all larval stages of both sexes and in adult females as well. During the imaginal ecdysis of males, however, the length of these sensilla increases to double that found in nymphs. Dendritic branches also increase in number. During postembryonic development, the number of sensory fibers in the antennal flagellum increases nearly 20-fold, from 14,000 in the first larval instar to about 270,000 in the adult male. The greatest increase, approximately 90%, occurs during the last developmental stage.
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Cucarachas/ultraestructura , Periplaneta/ultraestructura , Órganos de los Sentidos/ultraestructura , Animales , Femenino , Flagelos/ultraestructura , Cabello/ultraestructura , Larva/ultraestructura , Masculino , Microscopía Electrónica de Rastreo , Ninfa/ultraestructura , Órganos de los Sentidos/crecimiento & desarrollo , Órganos de los Sentidos/inervación , Factores SexualesRESUMEN
Glycolate oxidase (GO) has been identified in the endocyanom Cyanophora paradoxa which has peroxisome-like organelles and cyanelles instead of chloroplasts. The enzyme used or formed equimolar amounts of O(2) or H(2)O(2) and glyoxylate, respectively. Aerobically, the enzyme did not reduce the artificial electron acceptor dichlorophenol indophenol. However, after an inhibitor of glycolate dehydrogenase, KCN (2 millimolar), was added to the assay medium, considerable aerobic glycolate:dichlorophenol indophenol reductase activity was detectable. The leaf GO inhibitor 2-hydroxybutynoate (30 micromolar), which binds irreversibly to the flavin moiety of the active site of leaf GO, inhibited Cyanophora GO and pea (Pisum sativum L.) GO to the same extent. This suggests that the active sites of both enzymes are similar. Cyanophora GO and pea GO cannot oxidize d-lactate. In contrast to GO from pea or other organisms, the affinity of Cyanophora GO for l-lactate is very low (K(m) 25 millimolar). Another important difference is that Cyanophora GO produced sigmoidal kinetics with O(2) as varied substrate, whereas pea GO produced normal Michaelis-Menten kinetics. It is concluded that there is considerable inhomogeneity among the glycolate-oxidizing enzymes from Cyanophora, pea, and other organisms. The specific catalase activity in Cyanophora was only one-tenth of that in leaves. NADH-and NADPH-dependent hydroxypyruvate reductase (HPR) and glyoxylate reductase activities were detected in Cyanophora. NADH-HPR was markedly inhibited by hydroxypyruvate above 0.5 millimolar. Variable substrate inhibition was observed with glyoxylate in homogenates from different algal cultures. It is proposed that Cyanophora has multiple forms of HPR and glyoxylate reductase, but no enzyme clearly resembling leaf peroxisomal HPR was identified in these homogenates. Moreover, no serine:glyoxylate aminotransferase activity was detected. These results collectively indicate the possibility that the glycolate metabolism in Cyanophora deviates from that in leaves.
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The U.S. Public Health Service (PHS) has recommended that all women of childbearing years, capable of becoming pregnant, consume 400 micrograms folic acid/d to reduce their risk of having a neural tube defect (NTD)-affected pregnancy. The U.S. Food and Drug Administration subsequently proposed a folate fortification scheme for cereal grains, which also allowed the continued fortification of breakfast cereals at 0.1 mg per serving. To determine the contribution of ready-to-eat breakfast cereals (RTEC) to folate intakes in women of childbearing years, data were analyzed from the U.S. Department of Agriculture's 1989-1991 Continuing Survey of Food Intakes by Individuals and 1987-1988 Nationwide Food Consumption Survey. Women consuming RTEC have higher intakes of folate than women reporting no RTEC consumption. Recent reports indicate that most women are unaware of the PHS recommendation to consume more folate, and many health professionals are not advising women of the need to consume adequate folate during childbearing years. The food industry has been an effective communicator of health and nutrition messages and should be encouraged to raise awareness about the role of folate in NTDs. Better analysis also needs to be conducted to identify women at risk of low folate intakes, so that targeted education efforts can be made and appropriate vehicles identified for delivering folate to these women.
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Ácido Fólico/administración & dosificación , Alimentos Fortificados , Industria de Procesamiento de Alimentos , Adulto , Dieta/normas , Grano Comestible , Femenino , Ácido Fólico/sangre , Industria de Procesamiento de Alimentos/normas , Humanos , Defectos del Tubo Neural/prevención & control , Encuestas Nutricionales , Embarazo , Estados Unidos , United States Public Health ServiceRESUMEN
A prospective transversal study was undertaken by occupational health physicians on more than 4,000 individuals including almost 800 women working in the same company with the following aims: a) to compare the prevalence of a certain number of classically recognized cardiovascular risk factors in 2 types of populations, service versus manufacturing industries, in the Paris region; and b) to understand these populations better so as to develop educational and information campaigns specifically adapted to their needs. Several elements were recorded in a computer data bank during the physical examination: blood pressure, blood cholesterol, smoking history, blood triglycerides, blood sugar, the ratio of measured to theoretical weight and physical activity. For each of these parameters, a value above a determined threshold level was defined as a risk factor. For men working in service industries, the percentages of heavy smokers (24%), hypercholesterolemia (18%), and hyperglycemia (7%) were significantly higher than in the manufacturing sector (19.3, 15 and 2.4%, respectively). In manufacturing industries, the percentages of men with hypertension (15%), hypertriglyceridemia (10%), who were overweight (24%) or had a low high density lipoprotein level (10%) were significantly higher than in the service sector (3.1, 7.5, 20 or 8.2%, respectively). The percentage of women smoking more than 20 g of tobacco per day (25.5%) in the service sector was significantly higher than that in manufacturing industries (4.25%). In contrast, in the manufacturing sector, the percentages of hypertensive (6%) and obese (24%) women were significantly higher than those in the service industries (1.1 and 16%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
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Enfermedades Cardiovasculares/epidemiología , Enfermedades Profesionales/prevención & control , Adulto , Femenino , Francia/epidemiología , Encuestas Epidemiológicas , Humanos , Industrias , Masculino , Persona de Mediana Edad , Medicina del Trabajo , Prevalencia , Estudios Prospectivos , Factores de RiesgoRESUMEN
BACKGROUND AND OBJECTIVE: A newly developed radio-frequency monopolar needle electrode was evaluated in vitro on porcine tongues. PATIENTS AND METHODS: Porcine tongues with different tissue temperatures (20+/-1) degrees C and (32+/-2) degrees C were coagulated for 90 s. In a second step, 23 coagulations at 7 W were applied (34+/-2) degrees C. RESULTS: The volume of the lesion correlated well with increasing temperature. In step two, the mean energy was 238 J and the mean volume of the lesion was 507 mm(3) (100+/-15)%. Prolonged energy application did not correlate with a larger volume of the lesion. CONCLUSION: The new radio-frequency needle electrode can reduce tongue volume in a precise and controlled manner (SD+/-15%).
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Electrocoagulación/instrumentación , Lengua/cirugía , Animales , Conductividad Eléctrica , Diseño de Equipo , Técnicas In Vitro , Porcinos , Temperatura , Lengua/patologíaRESUMEN
Three homeobox-containing genes from the nematode Caenorhabditis elegans are described. Two of them (ceh-11 and ceh-12) were isolated from a genomic library by hybridization at low stringency with the Ascaris lumbricoides homeobox AHB-1. The first clone contains a homeobox defining a new class of homeoboxes (ceh-11). This gene maps on the third chromosome of C. elegans, at the same locus as egl-5, a gene already known to be essential for the determination of specific neurons. In the second clone, sequence analysis revealed the existence of the third helix of a putative homeobox (ceh-12) which is interrupted by an intron located upstream of the codon for the amino acid 45 of the homeodomain. Using the ceh-11 homeobox as a probe, a third homeobox (ceh-13) was isolated from a cDNA library. As ceh-13 belongs to the labial class of homeoboxes, we conclude that, at the time when the nematode lineage diverged from the myriapod-insect and the vertebrate lineages, the duplication which led to the Antp and the labial families of homeoboxes had already taken place.
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Proteínas de Caenorhabditis elegans , Caenorhabditis/genética , Genes Homeobox , Factores de Transcripción , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Mapeo Cromosómico , Clonación Molecular , ADN/genética , ADN/aislamiento & purificación , Datos de Secuencia Molecular , Mapeo RestrictivoRESUMEN
A metacercarial infestation is reported in Canadian Umbra limi and a mass infestation by trematodes in Physa sp. from the same locality. Trials made by using parasitised snails showed that both parasites are not of the same species.
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Enfermedades de los Peces/parasitología , Caracoles/parasitología , Trematodos , Infecciones por Trematodos/veterinaria , Animales , Especificidad de la Especie , Infecciones por Trematodos/parasitologíaRESUMEN
An rDNA size class in the genome of the nematode Ascaris lumbricoides is described which is interrupted by a 4.5-kb long intervening sequence located in the 26S coding region. This molecular form occurs in approximately 15 copies per haploid genome and amounts to approximately 5% of the total nuclear rDNA. Intervening sequences are present only in the 8.8-kb rDNA, but not in the 8.4-kb rDNA repeating units of A. lumbricoides. Cloning of the interrupted rDNA units revealed, in addition to the main 4.5-kb insertion, shorter intervening sequences of 4-kb and 119-bp length. Both shorter rDNA forms are present in the single copy range of the haploid genome. Sequence analyses of the intervening sequence/rDNA junctions show an identical right-hand junction for all of the three different rDNA forms. The two shorter intervening sequences are a coterminal subset of the right-hand end of the main 4.5-kb insertion, whereas all three insertions have a different left-hand junction with the coding region of rDNA. Each intervening sequence is flanked by a short direct repeat of variable length, being only once present in the uninterrupted rDNA. The intervening sequences of A. lumbricoides show striking similarity to the organization of type I insertion family in dipteran flies, even though they are inserted at different positions in the 26S coding region. Additional rDNA intervening sequences may be present outside of the rDNA cluster, but in not more than 15-20 homologous copies per haploid genome.