Pyrolytic conversion of waste plastics to energy products: A review on yields, properties, and production costs.

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.

Effectiveness of Implant Therapy Analyzed in a Swedish Population: Prevalence of Peri-implantitis.

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).

Effective doses from scan projection radiographs of the head: impact of different scanning practices and comparison with conventional radiography.

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.

Neurotoxicity of exposures to aluminium welding fumes in the truck trailer construction industry.

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.

[Effect of high frequency application on the tongue base. In vitro results of "radiofrequency application" on the porcine tongue base]. / Auswirkung der Hochfrequenzapplikation auf den Zungengrund. In-vitro-Ergebnisse der "radio-frequency application" an Schweinezungen.

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%).

Translationally controlled tumor protein: a protein identified in several nontumoral cells including erythrocytes.

The translationally controlled tumor protein (TCTP) is a growth-related protein which is regulated at the translational level. It is present in mammals, higher plants and Saccharomyces cerevisiae. This study was undertaken to localize and further characterize the TCTP in human cell lysates using two-dimensional gel electrophoresis, monoclonal antibodies, and 45Ca-gel overlay. TCTP was found in several healthy and tumoral cells including erythrocytes, hepatocytes, macrophages, platelets, keratinocytes, erythroleukemia cells, gliomas, melanomas, hepatoblastomas, and lymphomas. It could not be detected in kidney and renal cell carcinoma (RCC). A monoclonal antibody raised against TCTP detected three isoforms likely due to post-translational modifications. A calcium binding property was found as well as heat stability and cytoplasmic localization. The high degree of homology from plants to man and its expression in many tissues suggests that TCTP most likely has a cell housekeeping function.

A food industry perspective on folic acid fortification.

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.

Two-dimensional gel electrophoresis of Escherichia coli homogenates: the Escherichia coli SWISS-2DPAGE database.

Numerous Escherichia coli proteins have already been characterized by two-dimensional gel electrophoresis (2-D PAGE), using carrier ampholytes in the first dimension (VanBogelen, R. A., Sankar, P., Clark, R. L., Bogan, J. A. and Neidhardt, F. C., Electrophoresis 1992, 13, 1014-1054). We present here a reference protein map of E. coli obtained with immobilized pH gradients (IPG) and available in a SWISS-2DPAGE format. Out of the protein spots identified in the E. coli gene protein database by Neidhardt's group, 153 have been identified in the E. coli gene protein database by Neihardt's group, 153 have been identified on the E. coli SWISS-2DPAGE database map by gel comparison and most of them were confirmed either by the analysis of amino acid composition (AAC) and/or N-terminal microsequencing. Additionally, five as yet unsequenced proteins were found. The E. coli SWISS-2DPAGE database is part of the ExPASy molecular biology server accessible through the Word Wide Web network.

The yeast SWISS-2DPAGE database.

The systematic sequencing of the yeast genome will soon be completed. A new challenge has been launched by the EUROFAN (European Functional Analysis) project whose goal is to elucidate the physiological and biochemical function of newly discovered open reading frames (ORF) from yeast. One of the approaches is to use protein-based technologies such as two-dimensional gel electrophoresis and protein identification in order to establish a yeast reference map. Modified protein patterns can be compared to the reference map which hopefully will help identify changes related, for example, to growth processes or developmental events. This paper describes the yeast SWISS-2DPAGE database in which charge separation was obtained using immobilized pH gradient (IPG). Proteins identified by gel comparison, amino acid composition analysis and/or microsequencing are recorded and described in an accessible uniform format. We have identified more than one hundred polypeptides, several of which were newly mapped. In addition, the yeast SWISS-2DPAGE database can be freely accessed through the World Wide Web (WWW) network on the ExPASy molecular biology server.

[Cardiovascular risk factors in 4,215 subjects in the service and industrial sectors (the CESAME survey)]. / Facteurs de risque cardio-vascularies chez 4,215 sujets du secteur tertiaire et industriel (enquête CESAME).

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)

Identification and Characterization of Glycolate Oxidase and Related Enzymes from the Endocyanotic Alga Cyanophora paradoxa and from Pea Leaves.

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.

Cloning and expression in vitro of a gene encoding tRNAArgACG from the nematode Caenorhabditis elegans.

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.

Cloning and analysis of three new homeobox genes from the nematode Caenorhabditis elegans.

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.

Quality of care review: recent experience in Arizona.

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.

Intervening sequences in the ribosomal RNA genes of Ascaris lumbricoides: DNA sequences at junctions and genomic organization.

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.

[A metacercarial disease in the dogfish species Umbra limi (Teleostei) and a trematode infestation in a Physa sp. (Mollusca)]. / Eine Metazerkarienerkrankung bei der Hundsfischart Umbra limi (Teleostei) und eine Trematodeninfestation bei einer Physa sp. (Mollusca).

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.