Short-Term changes in hepatic HMG-CoA reductase in rats fed diets containing cholesterol or oat bran

In vivo regulation of hepatic HMG-CoA reductase (HMGR) (mevalonate: NADP⁺ oxidoreductase [acylating CoA]; EC 1.1.1.34] by phosphorylation/dephosphorylation has not been demonstrated. Rats were meal-fed semipurified diets; effects of inclusion of cholesterol (2%) or oat bran (15%) in a single meal on expressed (phosphorylated) and total (dephosphorylated) activities of HMGR were measured from 15 min to 4 hr after presentation of the meal. Expressed activity was not significantly altered in response to the control diet during the time periods examined, while total HMGR activity declined by 15 min and increased through 4 hr to an activity about 1.5 times control levels. Addition of cholesterol resulted in little change in expressed activity but a greater and more sustained reduction in total activity. Oat bran caused reductions in both total and expressed activities, which were maintained through 4 hr. Total HMGR activity was best correlated with apparent demand for cholesterol synthesis.     

Soil test calibration for upland rice in south western Nigeria

The relationship between soil test values and yield response due to fertilization is usually described by response models and would indicate test value where response is expected. Upland rice grain yield was used to define relative yield in terms of yield from control (no fertilizer; or minus nutrient) treatment expressed as percent of complete treatment.Regression analyses show that soil properties were related to both relative yield definitions. Critical nutrient levels and calibration obtained with Cate and Nelson's technique were indicative for soil nutrients. Although relative yield based on fertilizer and control (no fertilizer) treatments has the advantage that many nutrients can be calibrated at the same time, lower R2 values observed in this study with upland rice mean that it cannot be recommended as replacement to conventional relative yield.     

氢燃料电动汽车-21世纪汽车产品的方向

基于节能和环保的要求,国际知名汽车集团都在研制代用燃料和电动汽车。电动汽车的能源和传动方式成为研究的关键。通过对四个主要汽车生产国的六大汽车集团在代用燃料和电动汽车传动方面研究与进展的分析，认为研发使用氢燃料电池的电动汽车是近期汽车产品最有前途的新方向。     

Proteomic Profiling of the First Human Dental Pulp Mesenchymal Stem/Stromal Cells from Carbonic Anhydrase II Deficiency Osteopetrosis Patients

Osteopetrosis is a hereditary disorder characterized by sclerotic, thick, weak, and brittle bone. The biological behavior of mesenchymal cells obtained from osteopetrosis patients has not been well-studied. Isolated mesenchymal stem/stromal cells from dental pulp (DP-MSSCs) of recently extracted deciduous teeth from osteopetrosis (OP) patients and healthy controls (HCs) were compared. We evaluated whether the dental pulp of OP patients has a population of MSSCs with similar multilineage differentiation capability to DP-MSSCs of healthy subjects. Stem/progenitor cells were characterized using immunohistochemistry, flow cytometry, and proteomics. Our DP-MSSCs were strongly positive for CD44, CD73, CD105, and CD90. DP-MSSCs obtained from HC subjects and OP patients showed similar patterns of proliferation and differentiation as well as gene expression. Proteomic analysis identified 1499 unique proteins with 94.3% similarity in global protein fingerprints of HCs and OP patients. Interestingly, we observed subtle differences in expressed proteins of osteopetrosis disease-related in pathways, including MAPK, ERK 1/2, PI3K, and integrin, rather than in the stem cell signaling network. Our findings of similar protein expression signatures in DP-MSSCs of HC and OP patients are of paramount interest, and further in vivo validation study is needed. There is the possibility that OP patients could have their exfoliating deciduous teeth banked for future use in regenerative dentistry.     

Biodegradation of low density polyethylene (LDPE) by certain indigenous bacteria and fungi

Low-density polyethylene (LDPE) is an environmental problem because it is discarded randomly, and because in dumpsites, it does not readily degrade. This study reports evidence of successful biodegradation by two fungal species (Aspergillus flavus MCP₅ and Aspergillus flavus MMP₁₀) and eight bacterial species (Acinetobacter sp. MGP₁, Bacillus sp. MGP₁, Pseudomonas sp. MMP₁, Bacillus sp. MMP₅, Staphylococcus sp. MMP₁₀, Bacillus sp. MGP₁, Micrococcus sp. MMP₅ and Bacillus sp. MMP₁₀). These were demonstrated to have used LDPE as both nitrogen and carbon source. LDPE-users were then characterised and identified using standard microbiological procedures. Biodegradation study was done using selected bacterial and fungal isolates, singly and in consortia, to degrade heat-sterilised ground LDPE in media devoid of carbon source, and carbon and nitrogen source. Biodegradation was monitored using gravimetric methods and Fourier transform infrared spectroscopy. This study revealed some microorganisms can use LDPE as both nitrogen and carbon source in the absence of additives.     

Thermo-catalytic conversion of greenhouse gases (CO2 and CH4) to CO-rich hydrogen by CeO2 modified calcium iron oxide supported nickel catalyst

In this study, the thermo-catalytic conversion of two principal greenhouse gases (methane and carbon dioxide) to carbon monoxide (CO)-rich hydrogen (H₂) is investigated over cerium oxide (CeO₂) promoted calcium ferrite supported nickel (Ni/CaFe₂O₄) catalyst. The CeO₂ promoted Ni/CaFe₂O₄ catalyst was prepared using wet-impregnation technique. To ascertain the physicochemical properties, the as-prepared catalyst was characterized using various instrument techniques. The characterization of the catalysts reveals that CeO₂-Ni/CaFe₂O₄ possesses suitable physicochemical properties for the conversion of methane (CH₄) and carbon dioxide (CO₂) to CO-rich H₂. The thermo-catalytic reaction revealed that the CeO₂ promoted Ni/CaFe₂O₄ catalyst displayed a higher CH₄ and CO₂ conversions of 90.04% and 91.2%, respectively, at a temperature of 1073 K compared to the unpromoted catalyst. The highest H₂ and CO yields of 78% and 76%, respectively, were obtained over the CeO₂-Ni/CaFe₂O₄ at 1073 K and CH₄/CO₂ ratio of 1. The CeO₂ promoted Ni/CaFe₂O₄ catalyst remained stable throughout the 30 hours time on stream (TOS) while that of the unpromoted Ni/CaFe₂O₄ catalyst sharply decreased after 22 hours TOS. The characterization of the used catalysts confirms the evidence of carbon depositions on the unpromoted Ni/CaFe₂O₄ which is solely responsible for its deactivation. Whereas, there was a slightly gasifiable carbon deposited on the CeO₂ promoted Ni/CaFe₂O₄ catalyst which could be ascribed to the interaction effect of the CeO₂ promoter on the Ni/CaFe₂O₄ catalyst.