Biomedical subjects

R Sneath

Publications and source records attributed to R Sneath.

4 recordsLinked to original sources

PubMed2004

Hydrogen sulphide removal by activated sludge diffusion.

Odours from wastewater treatment plants comprise a mixture of various gases, of which hydrogen sulphide (H2S) is the main constituent. Microorganisms commonly found in wastewater can degrade sulphurous compounds. Therefore, the use of activated sludge (AS) for odour control offers an alternative to traditional waste gas treatment processes, such as biofilters, bioscrubbers and biotrickling filters, both in practical terms (use of existing facilities) and economically (minimal capital cost). The performance of AS diffusion as a bioscrubber for removing H2S at concentrations at 25, 75 and 150 ppmv was evaluated. Pilot-scale trials were undertaken using parallel 60-L aeration tanks and 20-L clarifier reactors at the Bedford Sewage Treatment Works, Carington, UK. Olfactometry measurements were also carried out to determine whether there was any increase in odour concentration owing to H2S diffusion. Hydrogen sulphide removal rates of 100% were obtained, with no noticeable increase in odour concentration throughout the trials as measured by olfactometry. Odour concentration was highest at the beginning of the trials and lowest during the high H2S dosing period, with similar values being obtained for test and control. It was concluded that AS diffusion is an effective bioscrubber for the removal of H2S odour.

Air Pollutants↗

PubMed2001

Potential for ammonia recapture by farm woodlands: design and application of a new experimental facility.

There has been increasing pressure on farmers in Europe to reduce the emissions of ammonia from their land. Due to the current financial climate in which farmers have to operate, it is important to identify ammonia control measures that can be adopted with minimum cost. The planting of trees around farmland and buildings has been identified as a potentially effective and low-cost measure to enhance ammonia recapture at a farm level and reduce long-range atmospheric transport. This work assesses experimentally what fraction of ammonia farm woodlands could potentially remove from the atmosphere. We constructed an experimental facility in southern Scotland to simulate a woodland shelterbelt planted in proximity to a small poultry unit. By measuring horizontal and vertical ammonia concentration profiles within the woodland, and comparing this to the concentration of an inert tracer (SF6) we estimate the depletion of ammonia due to dry deposition to the woodland canopy. Together with measurements of mean ammonia concentrations and throughfall fluxes of nitrogen, this information is used to provide a first estimate of the fraction of emitted ammonia that is recaptured by the woodland canopy. Analysis of these data give a lower limit of recapture of emitted ammonia, at the experimental facility, of 3%. By careful design of shelterbelt woodlands this figure could be significantly higher.

Agriculture↗

PubMed1992

Osteogenic sarcoma and Rothmund Thomson syndrome.

Rothmund Thomson syndrome (RTS) is a rare autosomal recessive disorder characterised by poikiloderma, dermal atrophy, dystrophic nails, short stature and hypogonadism. An increased incidence of malignancy has been reported in patients with this syndrome secondary, it is postulated, to DNA repair defects. We report the occurrence of an osteogenic sarcoma in an 11-year-old Irish girl with RTS. Although fibroblast cultures demonstrated enhanced radiosensitivity, there was no undue toxicity associated with treatment, which included methotrexate, cisplatinum and Adriamycin. Following conservative surgery, she is currently off treatment and disease-free 2 years from diagnosis.

Abnormalities, Multiple↗

PubMed1992

A comparison of two short intensive adjuvant chemotherapy regimens in operable osteosarcoma of limbs in children and young adults: the first study of the European Osteosarcoma Intergroup.

PURPOSE: A randomized pilot study was undertaken to assess the acute and chronic toxicities of two short intensive chemotherapy regimens, and to evaluate the feasibility of conservative surgery in this setting. Additional aims were to determine the clinical and radiologic response and the degree of histologic necrosis after chemotherapy. With extension of the study, eventual accrual was sufficient to compare disease-free survival (DFS) and overall survival (OS). PATIENTS AND METHODS: Between July 1983 and December 1986, the European Osteosarcoma Intergroup (EOI) entered 198 eligible patients with classic high-grade extremity osteosarcoma onto a randomized trial that compared doxorubicin (DOX) 25 mg/m2/d times three, intravenous (IV) bolus plus cisplatin (CDDP) 100 mg/m2, 24 hour infusion, every 3 weeks times six; the same combination was preceded 10 days earlier by high-dose methotrexate (HDMTX) 8 g/m2, 6-hour infusion, every 4.5 weeks times four. In the majority of patients (179), chemotherapy was commenced after biopsy; definitive surgery was scheduled at 9 weeks in both groups. RESULTS: Toxicities for both regimens did not differ substantially from those that occurred in other trials of adjuvant chemotherapy in osteosarcoma. Local recurrence (9%) and surgical complications (18%) after conservative surgery were acceptable. With a median follow-up of 53 months, DFS at 5 years is superior (P = .02) for DOX/CDDP, 57% versus 41%, although OS, 64% versus 50%, is not different significantly (P = .10). In a subset of 66 patients for whom pathologic data on the resected specimen were available, DFS (P = .003) and OS (P = .008) were better for those who demonstrated > or = 90% necrosis. CONCLUSION: A brief intensive chemotherapy regimen of DOX/CDDP has produced excellent long-term results, which are similar to those that have been achieved in cooperative group studies of longer, more complex multiagent chemotherapy, and provide the basis for a direct comparison in the next EOI study.

Adolescent↗