Opportunities of waste heat recovery from various sources: Review of technologies and implementation.

Waste heat recovery (WHR) using conventional technologies can provide appreciable amounts of useful energy from waste heat (WH) sources, thus reducing the overall energy consumption of systems for economic purposes, as well as ameliorating the impact of fossil fuel-based CO2 emissions on the environment. In the literature survey, WHR technologies and techniques, classifications and applications are considered and adequately discussed. The barriers affecting the development and utilization of systems of WHR, as well as possible solutions are presented. Available techniques of WHR are also discussed extensively, with a particular interest in their progressive improvements, prospects, and challenges. The economic viability of various WHR techniques is also taken into account considering their payback period (PBP), especially in the food industry. A novel research area wherein the recovered WH of flue gases from heavy-duty electric generators was utilized for agro-products drying has been identified, which may be useful in the agro-food processing industries. Furthermore, an in-depth discussion on the appropriateness and applicability of WHR technology in the maritime sector is given a prominent touch. In many review works involving WHR, different areas such as WHR sources, methods, technologies, or applications were discussed, albeit not in a comprehensive way touching on all-important aspects of this branch of knowledge. However, in this paper, a more holistic approach is followed. Furthermore, many recently published articles in different areas of WHR have been carefully examined and the recent findings provided are presented in this work. The recovery of waste energy and its utilization is capable of significantly dropping the level of production costs in the industrial sector and harmful emissions to the environment. Some of the benefits derivable from the application of WHR in the industries may include a reduction in energy, capital, and operating costs, which translate to reduced cost of finished products, and the mitigation of environmental degradation through the reduction of the emission of air pollutants and greenhouse gases. Future perspectives on the development and implementation of WHR technologies are presented in the conclusions section.

Possible serotonin syndrome with carbidopa-levodopa and linezolid.

WHAT IS KNOWN AND OBJECTIVE: Serotonin syndrome (SS) can occur when linezolid is combined with other serotonergic agents. CASE DESCRIPTION: We report a case of possible SS in an elderly patient receiving linezolid in combination with carbidopa-levodopa (CL). WHAT IS NEW AND CONCLUSION: Although certain classes of agents are commonly reported as causing SS among patients receiving linezolid, there are no specific case reports detailing this reaction with CL. Linezolid combined with CL should generally be avoided; however, if linezolid must be used, discontinuation of other agents with serotonergic activity is recommended with careful monitoring for signs and symptoms of SS.

HIV/AIDS-Related Knowledge and Attitudes of Pregnant Women In Delta State; Nigeria

HIV/AIDS has become a global health challenge and; with no cure presently; prevention is the only available option in combating it. The aim of the study was to determine risk factors for HIV/AIDS. While most of the women (91) were aware of HIV/AIDS; and that it could be transmitted sexually (95.6) and through infected blood (57.7); knowledge of its transmission through breast milk (36.8) and mother-to-child (27.5) was poor. Overall; 95.6of the women would not want to stay in the same house with an during antenatal visits; should focus on all the modes of transmission; prevention and treatment of HIV/AIDS

Knowledge attitude to modern family planning methods in Abraka communities, Delta State, Nigeria.

OBJECTIVE: To assess the level of regard and misconceptions of modern family planning methods in Abraka communities. METHODS: The interviewer's administered questionnaire method was used to gather the required information from 657 respondents randomly chosen from PO, Ajalomi, Erho, Oria, Otorho, Umeghe, Urhuoka and Uruagbesa communities in Abraka kingdom. RESULTS: Results show that 75.3% of those interviewed were aware of modern family planning but only 42.9% were using it to plan their families. Those using condom, safe periods and withdrawal constitute 32.6% of the 42.9% figure. Thus, data indicate a fairly high degree of awareness but little regard for family planning. CONCLUSION: Campaigns should be organized in order to educate Abraka communities on the benefits and need for family planning. Government should provide quality, comprehensive and subsidized family planning services. In addition, research efforts should be intensified on how to take advantage of the traditional methods of family planning to systematically introduce the modern method, so as to gradually eliminate the associated bias and misconceptions associated with modern methods of family planning.

Quality of child health services in primary health care facilities in south-east Nigeria.

BACKGROUND: To assess the quality of child health services in primary health care (PHC) facilities in Calabar, south-east Nigeria. DESIGN: Cross-sectional, descriptive design. METHODS: Key informant interviews, structured observation, self-administered questionnaire and focus group discussion. SETTING: Calabar, south-east Nigeria. Participants All 10 PHC facilities in Calabar, 252 PHC workers serving in the facilities, and 76 mothers whose children received care in the facilities. OUTCOME MEASURES: Adequacy of structure (equipment and personnel); process (diagnosis, training and knowledge, use of national case-management algorithm, and supervision), and output (clients' satisfaction). MAIN RESULTS: PHC facilities were adequately equipped to the extent of providing immunization services and management of diarrhoea but not for other aspects of care expected of a PHC centre, including management of acute respiratory infections (ARI), a common problem in children in the region. Supply of essential drugs was inadequate in all centres and facilities for emergency care were lacking. Many of the health care workers (68.3%) had adequate training in immunization, and their knowledge scores on immunization issues (62%) was higher than in other aspect of PHC. Use of the national case management algorithm was low among PHC workers. Results of the focus group discussions with mothers showed that a few perceived quality of care to be poor. The main concerns were long waiting time, lack of essential drugs, and attitude of the health workers. CONCLUSIONS: Inadequacy in the quality of child health services in PHC facilities is a product of failures in a range of quality measures -- structural (lack of equipment and essential drugs), process failings (non-use of the national case management algorithm and lack of a protocol of systematic supervision of health workers). Efforts to improve the quality of child health services provided by PHC workers in the study setting and similar locales in less developed countries should focus not only on resource-intensive structural improvements, but also on cheap, cost-effective measures that address actual delivery of services (process), especially the proper use of national guidelines for case management, and meaningful supervision.

Antibodies to neuron-specific antigens in children with autism: possible cross-reaction with encephalitogenic proteins from milk, Chlamydia pneumoniae and Streptococcus group A.

We measured autoantibodies against nine different neuron-specific antigens and three cross-reactive peptides in the sera of autistic subjects and healthy controls by means of enzyme-linked immunosorbent assay (ELISA) testing. The antigens were myelin basic protein (MBP), myelin-associated glycoprotein (MAG), ganglioside (GM1), sulfatide (SULF), chondroitin sulfate (CONSO4), myelin oligodendrocyte glycoprotein (MOG), alpha,beta-crystallin (alpha,beta-CRYS), neurofilament proteins (NAFP), tubulin and three cross-reactive peptides, Chlamydia pneumoniae (CPP), streptococcal M protein (STM6P) and milk butyrophilin (BTN). Autistic children showed the highest levels of IgG, IgM and IgA antibodies against all neurologic antigens as well as the three cross-reactive peptides. These antibodies are specific because immune absorption demonstrated that only neuron-specific antigens or their cross-reactive epitopes could significantly reduce antibody levels. These antibodies may have been synthesized as a result of an alteration in the blood-brain barrier. This barrier promotes access of preexisting T-cells and central nervous system antigens to immunocompetent cells, which may start a vicious cycle. These results suggest a mechanism by which bacterial infections and milk antigens may modulate autoimmune responses in autism.

Critical control points of complementary food preparation and handling in eastern Nigeria.

OBJECTIVE: To investigate microbial contamination and critical control points (CCPs) in the preparation and handling of complementary foods in 120 households in Imo state, Nigeria. METHODS: The Hazard Analysis Critical Control Point (HACCP) approach was used to investigate processes and procedures that contributed to microbial contamination, growth and survival, and to identify points where controls could be applied to prevent or eliminate these microbiological hazards or reduce them to acceptable levels. Food samples were collected and tested microbiologically at different stages of preparation and handling. FINDINGS: During cooking, all foods attained temperatures capable of destroying vegetative forms of food-borne pathogens. However, the risk of contamination increased by storage of food at ambient temperature, by using insufficiently high temperatures to reheat the food, and by adding contaminated ingredients such as dried ground crayfish and soybean powder at stages where no further heat treatment was applied. The purchasing of contaminated raw foodstuffs and ingredients, particularly raw akamu, from vendors in open markets is also a CCP. CONCLUSION: Although an unsafe environment poses many hazards for children's food, the hygienic quality of prepared food can be assured if basic food safety principles are observed. When many factors contribute to food contamination, identification of CCPs becomes particularly important and can facilitate appropriate targeting of resources and prevention efforts.

Evaluation of the laboratory and environmental factors that induce seizures in photosensitive epilepsy.

This paper evaluates the laboratory and environmental factors that induce seizures in photosensitive epileptic patients. The aims are (i) to identify those factors that trigger seizures so that the patients could take preventive measures, (ii) to advise the patients on appropriate preventive measures that could be taken to avoid spontaneous seizures. Thirty-six photosensitive epileptic patients were studied. The electroencephalographic laboratory seizure-inducing factors identified were intermittent photic stimulation (IPS), flickering lights from both the TV and the visual display unit (VDU) at various flashes per second, grid patterns (vertical, horizontal lines, squares, black and white lines) of various cycles per degree, and blank screens. In the environmental factor investigation, 10 out of 36 patients had series of seizures induced by narrow stripes of black and white, or white and red striped coloured dresses especially, when stepping outdoors on sunny days. Other environmental factors identified include moving escalators; 'moving' trees, bushes, and houses when travelling in a vehicle, including trains; faceted patterns in the bathroom windows with light passing through; swirling light patterns especially on displayed objects of black and white colours; telegraphic post, gantry post, and luminance variance when stepping outdoors from the dark in bright sunlight. The effective preventive measures were: (i) patients should occlude one eye when travelling in a vehicle or using computers or when stepping outdoors on a sunny day, or when there are various patterns before them, (ii) patients should sit at least 3 metres away from the TV when watching a programme, (iii) they should avoid any object that transmits luminance variance; if this is not possible, they should occlude one eye.

Lead concentration in soil from a small 15th-century industrial site: occupational and environmental health implications.

Former industrial sites are often reclaimed for new homes and other occupational uses. Such sites may still contain toxic chemicals that could put the health of the community at risk. The persistence of these residual chemicals and their effects on human health must not be underestimated. Hence, there is a need to analyze such sites to ensure that the public health will not be put at risk. It is also essential that the levels of release of heavy metals into the environment be monitored and regulated. In this study the lead (Pb) concentration in soil from a small 15th-century industrial site was determined to assess and evaluate its occupational and environmental health implications. Concentrations of Pb measured by atomic absorption spectroscopy (AAS) and inductively coupled plasma-emission spectroscopy (ICP-AES) techniques were 4,298.755 mg/L (SD 0.316; RSD 0.5%) and 4,300 mg/L (SD 0.3809; RSD 0.8%), respectively, both above the safe limit. It is concluded that reclaiming a disused industrial site without adequate soil analysis and proper remediation would be likely to pose occupational and environmental health risks.

Complex interconvertibility of nitrogen oxides (NOX): impact on occupational and environmental health.

Oxides of nitrogen have been implicated in a vast number of environmental and occupational health effects, some of which lack concrete mechanisms. Whereas certain compelling pieces of evidence link a particular nitrogen oxide to a particular adverse health effect, other reports seem to implicate virtually all the oxides in one form of toxic process or the other. Such diversity has probably emerged because each oxide of nitrogen possesses a different oxidation state, in which each form exerts different important levels of biological activity. Most important, each nitrogen oxide readily interconverts into another oxide at a very fast rate. This property of rapid interconvertibility poses problems to researchers in identifying with great confidence the actual oxide of nitrogen that is responsible for a specific occupational and environmental health effect. This paper reviews the complex nature of the nitrogen oxides (represented collectively as NOX) to explore the extent to which their acute or chronic exposure could be associated with toxicity. The nomenclature of the nitrogen oxides is outlined as a necessity for clarity and simplicity in understanding their reactions and interconvertibility and how they affect health. The natural occurrence and sources of occupational and environmental exposures and effects are critically evaluated and analyzed.

Alcohol dependence: a critical look at the effects of alcohol metabolism.

This paper explores the metabolic consequences of alcohol misuse and identifies the pathophysiological reasons why alcohol, no matter what quantity is taken regularly, is not beneficial for the normal functioning of most body systems. Although moderate ethanol consumption may reduce stress and the risk of coronary heart disease, ethanol also exerts a direct toxicological effect because it interferes with hepatic metabolism and immune functions. Liver transplantation may be necessary for end-stage liver disease in alcoholics. A causal effect between alcohol intake and several cancers has been reported. Both environmental and genetic factors are involved in the susceptibility to alcoholism. An explanation of alcohol dependence as a family disease is introduced to shed light on the magnitude of its collateral effects on the family and on the community as a whole. The adverse effects of alcohol on pregnant women and the fetus are also discussed. To provide awareness of the effectiveness of community efforts, we examined the possible intervention strategies and the role of community care in this regard.

Mental imagery of photic stimulation provokes paroxysmal EEG activity in a photosensitive patient who self-induces seizures.

This article reports a case of a 14 year-old male photosensitive epileptic patient who was able to induce fits subjectively by the mental imagery of the effective visual stimuli. The patient underwent a comprehensive electroencephalographic (EEG) examination including hyperventilation. The basic EEG showed abnormalities. Intermittent photic (IPS) and pattern stimulations (PtnS), evoked photo and pattern paroxysmal responses (PPRs) within a wide range of frequencies for 2-50 flashes per second (fps) and 0.5-6 cycles per degree (cdp) respectively. The patient was able to reconstruct the PPRs mentally on exposure to the effective stimuli of 25 and 50 fps, and 2.0 and 3.25 cpd respectively. His cognitive functions were not affected when exposed to photostimulation. However, on exposure to pattern stimulation, he became totally confused and his consciousness was impaired. These findings showed that self-induction of fits in photosensitive epilepsy is a mental phenomenon which takes place with or without loss of cognitive function depending on the rate and frequency of the physical and 'imagined' stimuli.

Bitemporal hemianopia in photosensitive epilepsy: a case study.

This paper reports the occurrence of bilateral hemianopia in a 16 year old male who was having unusual seizures accompanied by severe migrainous headaches and loss of vision while watching a television programme and while playing with the computer. Electrophysiological tests not only confirmed his photo and pattern sensitivity, but also showed that he had bitemporal hemianopia. Hence, his basic EEG showed a great deal of abnormality including generalised spike and wave activity which was more marked in the temporal regions. The patient showed classical occipital spikes on exposure to 25 and 50 Hz of intermittent photic stimulation. Pattern sensitivity test evoked photo paroxysmal response within the range of 2-4.5 cycles per degree (cpd). The visual evoked response to binocular flash stimulation produced N2 at 74 ms, P2 at 112-118 ms and N3 at 168 ms. P2 amplitude was 15-17 uV. Monocular right stimulation produced N2 at 72 ms, P2 at 122-124 ms. Monocular left stimulation produced N2 at 82 ms, P2 at 120-124 ms of 14 uV and N3 at 178 ms. Pattern reversal stimulation produced some abnormality. Poor phase reversals were mainly seen to the left occiput with right eye stimulation and poor phase reversals to the right occiput with left eye stimulation. The pattern responses were of normal latency but showed a marked hemispheric asymmetry. The reduction of the response in the left hemisphere with right eye stimulation and the reduction in the right hemisphere with left eye stimulation would suggest the presence of bitemporal field deficit.

Protein-tyrosine phosphatase 1B is a negative regulator of insulin- and insulin-like growth factor-I-stimulated signaling.

To understand the physiological role of protein-tyrosine phosphatase 1B (PTPase 1B) in insulin and insulin-like growth factor-I (IGF-I) signaling, we established clonal cell lines overexpressing wild type or inactive mutant (C215S) PTPase 1B in cells overexpressing insulin (Hirc) or IGF-I (CIGFR) receptors. PTPase 1B overexpression in transfected cells was verified by immunoblot analysis with a monoclonal PTPase 1B antibody. Subfractionation of parental cells demonstrated that greater than 90% of PTPase activity was localized in the Triton X-100-soluble particulate (P1) cell fraction. PTPase activity in the P1 fraction of cells overexpressing wild type PTPase 1B was 3-6-fold higher than parental cells but was unaltered in all fractions from C215S PTPase 1B-containing cells. The overexpression of wild type and C215S PTPase 1B had no effects on intrinsic receptor kinase activity, growth rate, or general cell morphology. The effects of PTPase 1B overexpression on cellular protein tyrosine phosphorylation were examined by anti-phosphotyrosine immunoblot analysis. No differences were apparent under basal conditions, but hormone-stimulated receptor autophosphorylation and/or insulin receptor substrate tyrosine phosphorylation were inhibited in cells overexpressing wild type PTPase 1B and increased in cells expressing mutant PTPase 1B, in comparison with parental cells. Metabolic signaling, assessed by ligand-stimulated [14C]glucose incorporation into glycogen, was also inhibited in cells overexpressing active PTPase 1B and enhanced in cells containing C215S PTPase 1B. These data strongly suggest that PTPase 1B acts as a negative regulator of insulin and IGF-I signaling.

Visually-evoked pattern and photomyoclonic responses in video game and television epilepsy: case reports.

This research paper reports a case study of two male photosensitive epileptic patients, aged 14 and 16 years old respectively, whose epileptic seizures were often triggered by the flickers from television and video games respectively. The 14-year old patient had no family history of epilepsy, while the 16 year old had a family history of epilepsy. A comprehensive electroencephalogram (EEG), including hyperventilation, intermittent photic stimulation (IPS) and pattern stimulation were carried out on them and EEG abnormalities including photoparoxysmal responses (PPR) and generalized myoclonic responses were evoked. A thorough analysis of the EEG morphology of the myclonic responses and the clinical manifestations showed evidence of two separate entitles of seizures namely: visually evoked pattern-myoclonic responses (PTMR) and visually evoked photomyoclonic responses (PMR). PTMR was independent of flash rate and occurred before a PPR and at the same time as the flash rate, while PMR occurred after the PPR and was dependent on flash rate. These findings suggest that "Video Game" epilepsy is probably a pattern sensitive epilepsy, electronic screen being the source of the triggering patterns; hence, the morphology and the family histories and the myoclonic phenomena differ from those of pure photosensitive epilepsy.

The involvement of serotonin (5-hydroxytryptamine) in photosensitive epilepsy.

Over the last decade, vigorous efforts have been made by neuroscientists to unravel the cellular and molecular basis of photosensitive Epileptogenic activities in the central nervous system (CNS). Many neurotransmitters are implicated in brain activities but the extent to which they participate in these activities needs to be clarified. This review discusses the involvement of serotonin (5-hydroxytryptamine, 5-HT) in photosensitive epilepsy. The biosynthesis, metabolism, and structural and functional distribution of serotonin in the brain, and the role of 5-HT, its precursors, metabolites, receptors, agonists, antagonists, and the enzymes of reaction in photosensitive epileptogenic activity with reference to 5-HT cortical density, are discussed. The effects of biosynthetic and metabolic impairments in the serotonergic system, and the extent to which they contribute to the elicitation of myoclonic phenomena, hallucination, impulsivity, and migraine (HIMM) in photosensitive epilepsy are critically reviewed, and supported by evidence from animal models of photosensitive epilepsy. This evidence is correlated with the clinical findings in human photosensitive epilepsy.

Pulmonary metastasectomy as secondary treatment for testicular tumors.

Patients presenting with synchronous and metachronous metastases of nonseminomatous testicular tumors are candidates for pulmonary metastasectomy after receiving definitive primary treatment, which includes semicastration, eventually retroperitoneal lymphadenectomy, and definitely chemotherapy. One hundred four such patients (age, 14 to 79 years; median age, 27 years) underwent pulmonary metastasectomy from 1972 to 1990, representing 15.8% of the pulmonary metastasectomies performed during the same period. Of the 117 operations performed, eight were repeat operations. Median sternotomy, posterolateral and, later, transverse thoracotomies were the standard surgical approaches used to remove the single and multiple metastases randomly distributed in both lungs. Wedge resections and atypical segmentectomies (66%), lobectomies (15%), anatomic segmentectomies (9%), pneumonectomies (3%), bilobectomies (3%), and mediastinal lymphadenectomies (65.4%) were the various procedures performed. Of the 104 patients, metastasectomy was complete in 80 and incomplete in 24. The 30-day mortality was 2.0%. Life table analysis revealed a survival rate of 77%, 70%, 66%, and 59% at 1, 2, 3, and 5 years, respectively. Of all prognostic factors examined, complete resection of the metastases seems to be the most significant factor influencing the prognosis.

Genotypic evaluation of ocular pathologies in sickle cell diseases.

Sickle cell disease patients are known to manifest different types of ocular problems. These problems include proliferative and non-proliferative retinopathies, and refractive errors. The distribution of these pathologic and refractive problems among the sickle cell genotypes is analyzed according to the individual genotypes. Data collected from a total of 63 sickle cell disease patients who responded to the questionnaires shows that fifty-six percent (35) are males and forty-four percent (28) are females. The genotype distributions are: SS, 55% (34); SC, 33% (21); S-Thal, 11% (7); while 2% (1), is AS-genotype. Overall findings show that severe ophthalmic abnormalities were reported by approximately 90% of the respondents with sickle cell disease. The majority of sickle cell disease patients in this research show consistent susceptibility to both fungal and bacterial infections with varying degree of refractive errors. It is observed that refractive errors are prevalent in SC and S-Thal sickle cell genotypes, while the severity of anemia and painful crises are more prevalent in SS and S-Thal genotypes. Systemic ocular problems are also prevalent among the SC and S-Thal disease genotypes.

The frequency distribution of ocular disease by age in Imo State Nigeria.

BACKGROUND: A total of 600 'first-time served' patients with confirmed ocular pathologies visited our clinic between 1987 and 1988. METHODS: These patients and their ocular diseases were classified according to age, sex, and employment. Gender mix was 53.5 percent male, 46.5 percent female. RESULTS: Of the total disease conditions, 42 percent fell within the 0-30 age group, 44 percent fell within the 31-60 age group and 14 percent fell between 61-90. The relative incidence of ocular disease within this clinic population was: 32.8 percent conjunctivitis; 28.8 percent cataract; 15.5 percent glaucoma; 11.5 percent pterygium; 1.8 percent optic atrophy; and 9.5 percent other. CONCLUSIONS: Caution is made to generalize these data to the population at large since those without financial means were not represented in this study.