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Fossil fuel such as coal, natural gas, oil and recently shale gas are perhaps the most economically viable means for energy generation but are laden with inexhaustible environmental consequences. Thus, biofuel development has received tremendous support from all quarters in response to quest for energy security and clean energy. However, the rapid rate of development of bioenergy has also raised concern chiefly for its nexus with food security with some scholar considering it a disaster especially for countries in the global south. Due to her prime location along the equator, and the generally favourable climatic conditions all through the year, Nigeria is considered to have enormous potential for bioenergy development. Unfortunately, Nigeria is also highly ranked in the 2018 Global Hunger Index (GHI) of International Food Policy Research Institute (IFPRI). Rested mainly on exploratory approach, this study analyses the bioenergy potential of Nigeria and the implications of the fast-rising market on food security in the Nigerian context. Critical investigation on the food crop-bioenergy trade-offs was conducted while bioenergy development implications were analysed in the context of the four dimensions of food security. Lastly, mitigative measures to bioenergy development impacts were discussed and one key proposition is need to strengthen the second and third generation technology for biofuel production in Nigeria.

High-manganese steels (HMnS) are alloys with outstanding mechanical properties, but their application is inhibited by inherent limitations in conventional processing. Additive manufacturing (AM) provides an alternative to make use of the unique properties of HMnS due to strongly differing processing conditions. However, no established methodology exists currently to tailor metallic alloys specifically for AM. Therefore, a methodology combining theoretical and experimental screening was used to design a HMnS specifically suited for AM. First, different chemical compositions were screened with thermodynamics-based stacking fault energy (SFE) maps to predict the activation of transformation-induced plasticity (TRIP) and twinning-induced plasticity (TWIP). For experimental screening, selected X30MnAl23-# alloys (with # ≤ 2 wt%) were produced by laser metal deposition (LMD). The metal physical mechanisms active during solidification and plastic deformation were identified by multiscale microstructure characterization (XRD, OM, SEM, EBSD, EDX, EPMA, APT) and tensile testing. Finally, two steels with the highest work-hardening capacity and formability were applied in lattice structures produced by selective laser melting (SLM) and compared to benchmark 316L steel. The correlation of AM-specific features of HMnS and their effect on deformation behavior as well as the applicability of the used methodology are discussed to illustrate the effectiveness of the chosen approach toward the development of high performance materials for AM. Keywords: Fe-Mn-Al-C, Solidification, Deformation, Thermodynamics, Additive manufacturing

Discoveries of new multi-principal element alloys (MPEAs) with outstanding performance have been challenging due to the large complexity of the compositional space. Many existing highly alloyed steels already incorporate MPEA concepts and detailed research is readily available, which can be utilized for a more efficient design approach. Inspired by this consideration, Ni- and Co-additions to the Al14.6C4.9Fe53.6Mn26.9 (at%) high‑manganese steel were assessed to introduce B2-precipitates in addition to the κ-carbides to increase strength. Thermodynamic screening in the Al-C-Co-Fe-Mn-Ni system was performed with a custom calphad database and combined with experimental screening to identify novel MPEAs with enhanced mechanical properties. The selected MPEAs were produced by thermo-mechanical processing and the mechanisms active during annealing and deformation were investigated experimentally. The modification with Co did not result in the formation of B2-precipitates and improved mechanical properties. The Ni-added MPEA, Al14.7C4.7Fe49.9Mn26.4Ni4.2, revealed significant precipitation and dispersion hardening by nanoscale κ- and B2-phases combined with excellent strain hardening capacity due to slip band refinement-induced plasticity (SRIP). A combination of 1 to 1.2 GPa yield strength (21.3 % increase) with a total elongation of 20 to 10 % was achieved. The chosen methodology was efficient in the design of a novel MPEA with an improved strength-ductility synergy.

Background: Risk-stratification in pulmonary embolism (PE) includes clinical decision rules, biomarkers and signs of right ventricular (RV) overload. The vector electrocardiogram is a diagnostic tool in which the ECG-derived ventricular gradient optimized for right ventricular pressure overload (VG-RVPO) can be used to detect patients with increased pulmonary pressure. The primary aim of this study was to assess the association of VG-RVPO and CT-assessed RV/LV diameter ratio as well as the prognostic value of an abnormal VG-RVPO for early adverse events in PE patients. Methods: In this single-center retrospective study, adult patients with acute PE were identified via the hospital’s administrative system. Adverse events were defined as the combined outcome of 30-day overall mortality, recurrent venous thromboembolism, the need for mechanical ventilation, the need for inotropic or vasopressive therapy and/or cardiac resuscitation. Results: VG-RVPO analysis was available for 164 patients diagnosed with PE between December 2015 and September 2018. Abnormal VG-RVPO was associated with a CTPA-assessed RV/LV diameter ratio >1.0 (OR 2.0; 95%CI 1.0–3.9). The adverse 30-day composite outcome occurred in 16 of 66 patients (24%) with abnormal VG-RVPO compared to 22 of 98 patients (22%) with normal VG-RVPO (OR 1.1, 95%CI 0.53–2.3). The net reclassification improvement of VG-RVPO on top of RV dilatation for predicting early adverse events was -12%, indicating no additional prognostic value of VG-RVPO on top of RV/LV diameter ratio. Conclusions: Although we observed an association between RV dilatation, abnormal ECG-derived VG-RVPO was not associated with acute PE associated adverse events.

BackgroundWe evaluated combined targeting with cetuximab, an anti-epidermal growth factor receptor (EGFR) monoclonal antibody, and bevacizumab, an anti-vascular endothelial growth factor (VEGF) monoclonal antibody, in squamous cell carcinoma of the head and neck (SCCHN).Patients and methodsThe combination was studied in human endothelial cells and head and neck and lung cancer xenograft model systems. Patients with recurrent or metastatic SCCHN were treated with weekly cetuximab and bevacizumab, 15 mg/kg on day 1 given intravenously every 21 days, until disease progression. Analysis of tumor biomarkers and related serum cytokines was performed.ResultsCetuximab plus bevacizumab enhanced growth inhibition both in vitro and in vivo, and resulted in potent reduction in tumor vascularization. In the clinical trial, 46 eligible patients were enrolled. The objective response rate was 16% and the disease control rate 73%. The median progression-free survival and overall survival were 2.8 and 7.5 months, respectively. Grade 3-4 adverse events were expected and occurred in less than 10% of patients. transforming growth factor alpha, placenta-derived growth factor, EGFR, VEGFR2 increased and VEGF decreased after treatment but did not correlate with treatment efficacy.ConclusionsCetuximab and bevacizumab are supported by preclinical observations and are well tolerated and active in previously treated patients with SCCHN.