The feasibility of putrescible components of municipal solid waste for biomethane production at Hyderabad, Pakistan.

This study analyzes the feasibility of putrescible components of municipal solid waste (PCMSW) such as food waste (FW) and yard waste (YW) for methane production in Pakistan. The batch experiments have been conducted at two different inoculums to substrate ratios (ISRs) by using various inoculums under mesophilic condition. The highest methane yield of FW and YW is achieved to be 428 Nml g-1 volatile solids (VS) added and 304 Nml g-1 VS added respectively by using buffalo dung inoculum at ISR-5. While, lowest methane yield of FW and YW is obtained as 236 Nml g-1 VS added and 151Nml g-1 VS added respectively by using effluent from a continuous stirrer tank reactor as inoculum at ISR-3. The first order decay model has been introduced, which gives best fit for methane potential of PCMSW with buffalo dung inoculum. Additionally, the feasibility of PCMSW in terms of power generation potential has been analyzed. About 60.63 million m3/year energy can be generated by converting PCMSW into methane gas leading to power generation. The finding of this study concludes that the replacement of imported energy and reduction up to 1.62% in other primary energy sources would be achieved, if PCMSW are properly converted into energy through anaerobic digestion in Pakistan.

Energy recovery from organic fractions of municipal solid waste: A case study of Hyderabad city, Pakistan.

Non-renewable energy sources have remained the choice of the world for centuries. Rapid growth in population and industrialisation have caused their shortage and environmental degradation by using them. Thus, at the present rate of consumption, they will not last very long. In this prospective, this study has been conducted. The estimation of energy in terms of biogas and heat from various organic fractions of municipal solid waste is presented and discussed. The results show that organic fractions of municipal solid waste possess methane potential in the range of 3%-22% and their heat capacity ranges from 3007 to 20,099 kJ kg(-1) Also, theoretical biogas potential of different individual fruit as well as vegetable components and mixed food waste are analysed and estimated in the range of 608-1244 m(3) t(-1) Further, the share of bioenergy from municipal solid waste in the total primary energy supply in Pakistan has been estimated to be 1.82%. About 8.43% of present energy demand of the country could be met from municipal solid waste. The study leads us to the conclusion that the share of imported energy (i.e. 0.1% of total energy supply) and reduction in the amount of energy from fossil fuels can be achieved by adopting a waste-to-energy system in the country.

Methodological quality assessment of paper-based systematic reviews published in oral health.

OBJECTIVES: This study aimed to conduct a methodological assessment of paper-based systematic reviews (SR) published in oral health using a validated checklist. A secondary objective was to explore temporal trends on methodological quality. MATERIAL AND METHODS: Two electronic databases (OVID Medline and OVID EMBASE) were searched for paper-based SR of interventions published in oral health from inception to October 2014. Manual searches of the reference lists of paper-based SR were also conducted. Methodological quality of included paper-based SR was assessed using an 11-item questionnaire, Assessment of Multiple Systematic Reviews (AMSTAR) checklist. Methodological quality was summarized using the median and inter-quartile range (IQR) of the AMSTAR score over different categories and time periods. RESULTS: A total of 643 paper-based SR were included. The overall median AMSTAR score was 4 (IQR 2-6). The highest median score (5) was found in the pain dentistry and periodontology fields, while the lowest median score (3) was found in implant dentistry, restorative dentistry, oral medicine, and prosthodontics. The number of paper-based SR per year and the median AMSTAR score increased over time (median score in 1990s was 2 (IQR 2-3), 2000s was 4 (IQR 2-5), and 2010 onwards was 5 (IQR 3-6)). CONCLUSION: Although the methodological quality of paper-based SR published in oral health has improved in the last few years, there is still scope for improving quality in most evaluated dental specialties. CLINICAL RELEVANCE: Large-scale assessment of methodological quality of dental SR highlights areas of methodological strengths and weaknesses that can be targeted in future publications to encourage better quality review methodology.

New approaches for the prevention of airway infection in ventilated patients. Lessons learned from laboratory animal studies at the National Institutes of Health.

Despite early diagnosis and appropriate antibiotic therapy, ventilator-associated pneumonia (VAP) remains the leading cause of death from hospital-acquired infection in ventilator-dependent patients. Strategies to prevent bacterial colonization of the trachea and lungs are the key to decrease mortality, hospital length of stay, and cost. It is well established that the VAP can result from entry of infected oropharyngeal/gastric secretions into the lower airways. Aspiration may occur during 1) intubation, 2) mechanical ventilation through leakage around the tracheal tube cuff, 3) suctioning of the tracheal tube when bacteria can detach from the biofilm within the tube, or 4) areosolization of bacterial biofilm during mechanical ventilation through the tracheal tube or the ventilator circuit biofilm. From experimental studies in sheep, we drew 3 relevant conclusions: 1) The tracheal tube and neck should be oriented horizontal/below horizontal to prevent aspiration of colonized secretions and subsequent bacterial colonization of the lower respiratory tract. 2) Continuous aspiration of subglottic secretions (CASS) can lower bacterial colonization of the respiratory tract, but at the price of severe tracheal mucosal damage at the level of the suction port. 3) Coating the interior of the tracheal tube with bactericidal agents can prevent bacterial colonization of the tube surface and of the entire respiratory circuit, during 24 hours of mechanical ventilation.

Delirium after cataract extraction: a prospective study.

A prospective study of 350 consecutive in-patients undergoing cataract extraction revealed the incidence of postcataract extraction delirium to be 1.7%. While in one case the delirium was due to anticholinergic toxicity, in the remaining 5 cases no organic cause was evident. Sensory deprivation was present in 3 patients. In addition to organic causes sensory deprivation was found to be an important cause of postcataract extraction delirium.

INTRAOCULAR TENSION VARIATIONS WITH ELECTROCONVULSIVE THERAPY.

Intraocular tension variations following modified and direct ECT were studied in 40 psychiatric patients. A significant rise of intraocular pressure occurred under both conditions, but was more marked and longer lasting when succinylcholine was used.

Post - cataractomy delirium : a two year prospective study.

A two year prospective study of 221 consecutive inpatients undergoing cataractomy revealed the incidence of post-cataractomy delirium to be 1.8%. While in one case the delirium was due to anticholinergic toxicity, in the remaining three cases no organic cause was evident. Sensory deprivation was present in two patients. Preventive measures for the condition are discussed.

Simulated leg-length discrepancy: its effect on mean center-of-pressure position and postural sway.

We hypothesized that leg-length discrepancies of as little as 1cm would induce a significant postural shift and increase the extent of postural sway. We had 14 normal volunteers stand on a force platform with their feet in a standard position. Center-of-pressure data were recorded at 100Hz for 20 seconds while the subjects stood barefoot with no lifts or (in random order) with lifts of 1, 2, 3, and 4cm under their left and right feet. From these data we derived the mean center-of-pressure position and the extent of postural sway. Lifts of as little as 1cm shifted the mean center-of-pressure toward the longer leg to a statistically significant extent (p less than 0.001), the mean difference compared with the barefoot condition being 6.1% of the distance between the feet; increasing the discrepancy did not proportionately increase the effect. The postural sway (total travel of the center-of-pressure) in a mediolateral direction increased significantly with a 1cm discrepancy (p less than 0.01), and continued to increase in proportion to the magnitude of the discrepancy. There were no effects on anteroposterior position or sway and no influence of left-right dominance. These results support our hypothesis that a leg-length discrepancy of as little as 1cm may be biomechanically important.