8 research outputs found

    Composite Multi-Criteria Decision Analysis for Optimization of Hybrid Renewable Energy Systems for Geopolitical Zones in Nigeria

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    This paper presents eight hybrid renewable energy (RE) systems that are derived from solar, wind and biomass, with energy storage, to meet the energy demands of an average household in the six geopolitical zones of Nigeria. The resource assessments show that the solar insolation, wind speed (at 30 m hub height) and biomass in the country range, respectively, from 4.38–6.00 kWh/m2/day, 3.74 to 11.04 m/s and 5.709–15.80 kg/household/day. The HOMER software was used to obtain optimal configurations of the eight hybrid energy systems along the six geopolitical zones’ RE resources. The eight optimal systems were further subjected to a multi-criteria decision making (MCDM) analysis, which considers technical, economic, environmental and socio-cultural criteria. The TOPSIS-AHP composite procedure was adopted for the MCDM analysis in order to have more realistic criteria weighting factors. In all the eight techno-economic optimal system configurations considered, the biomass generator-solar PV-battery energy system (GPBES) was the best system for all the geopolitical zones. The best system has the potential of capturing carbon from the atmosphere, an attribute that is desirous for climate change mitigation. The cost of energy (COE) was seen to be within the range of 0.151–0.156 US/kWh,whichiscompetitivewiththeexistingelectricitycostfromthenationalgrid,average0.131US/kWh, which is competitive with the existing electricity cost from the national grid, average 0.131 US/kWh. It is shown that the Federal Government of Nigeria favorable energy policy towards the adoption of biomass-to-electricity systems would make the proposed system very affordable to the rural households

    Long‐term multicentre experience of adjuvant radiotherapy for pN3 squamous cell carcinoma of the penis

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    Objective To present the long‐term adjuvant radiotherapy outcomes of patients with pN3 squamous cell carcinoma of the penis (SCCp) treated at two UK centres. Patients and Methods We conducted a retrospective audit of all pN3 SCCp patients, deemed suitable for adjuvant therapy by a specialist multidisciplinary team at St George’s and Leeds Hospitals, who received adjuvant radiotherapy. Primary outcomes were recurrence‐free survival (RFS), cancer‐specific survival (CSS) and overall survival (OS). Secondary outcomes were time to adjuvant treatment, frequency of in‐field recurrence, site and side of recurrence, and dose and schedule of radiotherapy. Results A total of 146 patients were included: 121 completed radiotherapy, four did not complete radiotherapy and 21 did not start it. The median (interquartile range [IQR]) age was 59 (54–70)years. The 5‐year RFS was 51%, CSS was 51% and OS was 44%. Adjuvant radiotherapy was started at a median (IQR) of 75 (48–106) days. A dose of 45 Gy in 20 fractions was most commonly used. Of the 125 patients who started adjuvant treatment, 55 relapsed. Of these relapses, 30 occurred in an inguinal or pelvic nodal station and 26 of the 30 were in a radiation field. Relapses in 18 of the 55 cases were in visceral sites only and seven were in both nodal (non‐irradiated sites) and visceral sites. Doses of 50 Gy) were more commonly used after 2013. Conclusions Application of a standard radiotherapy protocol within a centralized supra‐network setting has achieved survival outcomes that would appear better than those previously documented for either radiotherapy or chemotherapy in a cohort with solely pN3 disease. The addition of adjuvant chemotherapy may improve these outcomes further. These data suggest that adjuvant radiotherapy has a role to play in the management of men with pN3 SCCp

    Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

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    Background Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications. Methods We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC). Findings In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683–0·717]). Interpretation In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required. Funding British Journal of Surgery Society

    World Congress Integrative Medicine & Health 2017: part two

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    Listeria monocytogenes, a food-borne pathogen

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    World Congress Integrative Medicine & Health 2017: part two

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