Production of Phenol-formaldehyde Adhesives from Catalytic Pyrolysis Oil

Phenol-formaldehyde adhesives are important adhesives known to have superior water resistance capacity and high mechanical strength when utilized in wood-based applications. Due to unsustainability and environmental issues associated with the use of fossil fuels, there is an urgent need to look for alternative raw materials, which are renewable in nature. Pinyon-juniper biomass has been found to be a suitable replacement for petroleum-based phenol because it is renewable, abundant, and readily available. In this thesis, bio-oil produced from the pyrolysis of pinyon-juniper biomass using red mud alumina catalyst was used to produce wood adhesives. The characterization of pinyon-juniper bio-oil showed the presence of phenolics, aromatic hydrocarbons, aliphatic hydrocarbons, carboxylic acids, ethers, ketones, aldehydes, and aliphatic alcohols. Resol synthesis parameters such as formaldehyde-to-phenol molar ratio (1.8 and 2), catalyst loading (0.25, 0.63, and 1.25 g of NaOH), reaction time (60 minutes), and reaction temperature (95°C), were investigated in the production of pinyon-juniper adhesives. Based on the results obtained, the extent of phenol substitution with pinyon-juniper bio-oil was dependent on the amount catalyst used during the synthesis process. The maximum phenol substitution of 80% was achieved using a catalyst loading of 1.25 g of NaOH while the minimum phenol substitution of 50% was obtained at a catalyst loading of 0.25 g of NaOH. Dry shear strength (8.99 to 12.73 MPa) and wet shear strength of (5.16 to 7.36 MPa) for both pure phenol-formaldehyde resols and pinyon-juniper substituted resols were comparable and exceeded the minimum requirement of 0.66 MPa for plywood. Finally, the chemical structure of pure phenol-formaldehyde resols showed the presence of more phenolic OH groups compared to pinyon-juniper substituted resols. This observation was corroborated by the higher concentration of free phenol in pure phenol-formaldehyde adhesives compared to pinyon-juniper substituted resols

Historical imperatives for the emergence of development and democracy: a perspective for the analysis of poor governance quality and state collapse in Africa

"Bad governance has often been identified as the explanans for the weakness and subsequent collapse of the African state. Derivatively, African rulers have been advised and admonished to govern their societies well. But these analyses, advices and admonitions have been undertaken with little recourse to material conditions that have influenced the emergence ofgood governance and economic development in modern societies with a view to addressing the issue of whether these conditions ar available in Africa. The following analysis tries to identify these conditions which are political-economic in nature and posits that they are lacking in Africa. Employing the method of process tracing in a narrative manner, it draws attention to the historical development of the lack of such conditions within the structures instituted by colonialis and maintained through neo-colonial policies. The paper concludes by advising the donor community and international agencies that without the creation of those or similar iperatives, all efforts at socio-economic development and state capacity building may come to nought." (author's abstract

Yellow fever childhood immunization coverage in Jos North Local Government Area, North Central Nigeria: 2015 – 2017

Background: The transmission of Yellow fever,a viral hemorrhagic feveris facilitated in countries which have close proximity to the mosquito vectors and large number of unvaccinated population. Globally, mass vaccination campaigns have significantlyreduced the incidence of this disease, but recent reports from the World Health Organization (WHO), indicates an increase in the rate of transmission, especially in Sub-Saharan Africa. Between 2017 and 2018,some Nigerian states including Plateau state reported confirmed cases of yellow fever. In this study, we assessed the yellow fever immunization coverage in Jos North Local Government area (LGA) of Plateau state.Methodology: A retrospective cross-sectional study was carried out to assess yellow fever immunization coverage in Jos North LGA over a 3-year period from January 2015 to December 2017, with data obtained from the Local Government Area office. This included both data from routine and supplemental immunization activities. The number of children immunized was then compared to the target population to assess coverage for each year.Results: Overall, 71, 734 children were immunized. This comprised of  infants 9-11 months 69,344(96.7%) and 1 -5 year old infants 2390(3.3%). The overall average immunization coverage was (21,514/92,652) 23.2% in 2015, (24,977/93,569) 26.6% in 2016, and (25,243/94,495) 26.7% in 2017, with a mean coverage of 25.5% over the 3 year period.Conclusion: Yellow fever immunization coverage in this LGA is low. Urgent work needs to be done to increase immunization coverage across the local government, and by extension the state and country, especially in view of the recent outbreak of yellow fever in some states.Key words: Yellow fever, Immunization, North-Central Nigeria

An unsuspected yellow fever and lassa fever in a tertiary healthcare facility in Jos, North Central, Nigeria: a case report

Background: Yellow Fever and Lassa Fever are both zoonotic diseases (Mosquito borne flavirus and Rodent borne arenavirus, respectively) and classified as viral haemorrhagic fevers (VHF) because of their common clinical presentations – especially fevers and bleeding during the terminal stages of the diseases. After an incubation period of 3 – 6 days in Yellow fever, and 2 – 21 days in Lassa fever: they present with fevers, rigors, headache, myalgia, nausea, and vomiting. Jaundice is noticed in Yellow fever, while Lassa in addition to other symptoms also present with sore throat (with patchy tonsillar exudate), dysphagia, dry cough, chest pain, and cramping abdominal pain, diarrhoea or epigastric pains. Gradual deterioration is associated with oedema of the face and neck, respiratory distress, pleural and pericardial effusions, encephalopathy, and haemorrhage from various sites (including hypotension and shock, nonrelated to blood loss). The laboratory confirmation from a specialized virology laboratory was conducted for both disease conditions using reverse transcriptase polymerase chain reaction (PCR) testing, with containment facilities (biosafety level 4).The management of each of these conditions is mainly supportive, although Ribavirin has significantly reduced mortality associated with Lassa fever; with best results obtained when drug is started early in the course of the illness. Reports of Yellow fever and Lassa fever co-infection are particularly scarce. The objective of this study was to report a successfully managed Case report in an Adolescent Child.Case Report: A 10 – year old boy with a positive history of contact with and adult (grandmother) who died from a febrile illness, bleeding from body orifices and jaundice; presented with high grade fever, sore throat abdominal pain and passage of loose watery stool. All these symptoms were persistent for more than twelve days despite antibiotics and antimalarial medications. He was ill looking, febrile, anicteric and had right upper quadrant tenderness/hepatomegaly. A diagnosis of viral haemorrhagic fever was made, he was admitted and nursed in the isolation ward, infection prevention and control measures were observed, he had baseline investigations, supportive care and Ribavirin. PCR results was positive for Yellow fever and Lassa fever. He responded to treatment, was discharged home, and recuperated well during his follow up visits.Conclusion: This case clearly illustrates the importance of having high index of suspicion following the significant history of contact with a probable case of viral haemorrhagic fever (absence of laboratory confirmation at the time of her death) by the index case, especially when there was non-response to routine treatment for common causes of fever in the community.Keywords: Yellow Fever, Lassa Fever, Viral Haemorrhagic Fever, Polymerase Chain Reactio

Diminished Superoxide Generation Is Associated With Respiratory Chain Dysfunction and Changes in the Mitochondrial Proteome of Sensory Neurons From Diabetic Rats

Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. See http://creativecommons.org/licenses/by-nc-nd/3.0/ for details.OBJECTIVE Impairments in mitochondrial function have been proposed to play a role in the etiology of diabetic sensory neuropathy. We tested the hypothesis that mitochondrial dysfunction in axons of sensory neurons in type 1 diabetes is due to abnormal activity of the respiratory chain and an altered mitochondrial proteome. RESEARCH DESIGN AND METHODS Proteomic analysis using stable isotope labeling with amino acids in cell culture (SILAC) determined expression of proteins in mitochondria from dorsal root ganglia (DRG) of control, 22-week-old streptozotocin (STZ)-diabetic rats, and diabetic rats treated with insulin. Rates of oxygen consumption and complex activities in mitochondria from DRG were measured. Fluorescence imaging of axons of cultured sensory neurons determined the effect of diabetes on mitochondrial polarization status, oxidative stress, and mitochondrial matrix-specific reactive oxygen species (ROS). RESULTS Proteins associated with mitochondrial dysfunction, oxidative phosphorylation, ubiquinone biosynthesis, and the citric acid cycle were downregulated in diabetic samples. For example, cytochrome c oxidase subunit IV (COX IV; a complex IV protein) and NADH dehydrogenase Fe-S protein 3 (NDUFS3; a complex I protein) were reduced by 29 and 36% (P < 0.05), respectively, in diabetes and confirmed previous Western blot studies. Respiration and mitochondrial complex activity was significantly decreased by 15 to 32% compared with control. The axons of diabetic neurons exhibited oxidative stress and depolarized mitochondria, an aberrant adaption to oligomycin-induced mitochondrial membrane hyperpolarization, but reduced levels of intramitochondrial superoxide compared with control. CONCLUSIONS Abnormal mitochondrial function correlated with a downregulation of mitochondrial proteins, with components of the respiratory chain targeted in lumbar DRG in diabetes. The reduced activity of the respiratory chain was associated with diminished superoxide generation within the mitochondrial matrix and did not contribute to oxidative stress in axons of diabetic neurons. Alternative pathways involving polyol pathway activity appear to contribute to raised ROS in axons of diabetic neurons under high glucose concentration.This work was supported by grants from the Juvenile Diabetes Research Foundation (#1-2008-280) and the National Institutes of Health to R.T.D. (grants NS-054847 and DK-073594). E.A. was supported by a grant from the National Science and Engineering Research Council (#3311686-06) to P.F. and subsequently by a postgraduate scholarship from the Manitoba Health Research Council. S.K.R.C. and E.Z. were supported by grants to P.F. from the Canadian Institutes for Health Research (#MOP-84214) and the Juvenile Diabetes Research Foundation (#1-2008-193). D.R.S. was supported by a grant to P.F. from the Manitoba Health Research Council. This work was also funded by the St. Boniface General Hospital and Research Foundation

Sensory neurons derived from diabetic rats have diminished internal Ca2+ stores linked to impaired re-uptake by the endoplasmic reticulum

Distal symmetrical sensory neuropathy in diabetes involves the dying back of axons, and the pathology equates with axonal dystrophy generated under conditions of aberrant Ca2+ signalling. Previous work has described abnormalities in Ca2+ homoeostasis in sensory and dorsal horn neurons acutely isolated from diabetic rodents. We extended this work by testing the hypothesis that sensory neurons exposed to long-term Type 1 diabetes in vivo would exhibit abnormal axonal Ca2+ homoeostasis and focused on the role of SERCA (sarcoplasmic/endoplasmic reticulum Ca2+-ATPase). DRG (dorsal root ganglia) sensory neurons from age-matched normal and 3–5-month-old STZ (streptozotocin)-diabetic rats (an experimental model of Type 1 diabetes) were cultured. At 1–2 days in vitro an array of parameters were measured to investigate Ca2+ homoeostasis including (i) axonal levels of intracellular Ca2+, (ii) Ca2+ uptake by the ER (endoplasmic reticulum), (iii) assessment of Ca2+ signalling following a long-term thapsigargin-induced blockade of SERCA and (iv) determination of expression of ER mass and stress markers using immunocytochemistry and Western blotting. KCl- and caffeine-induced Ca2+ transients in axons were 2-fold lower in cultures of diabetic neurons compared with normal neurons indicative of reduced ER calcium loading. The rate of uptake of Ca2+ into the ER was reduced by 2-fold (P<0.05) in diabetic neurons, while markers for ER mass and ER stress were unchanged. Abnormalities in Ca2+ homoeostasis in diabetic neurons could be mimicked via long-term inhibition of SERCA in normal neurons. In summary, axons of neurons from diabetic rats exhibited aberrant Ca2+ homoeo<1?show=[fo]?>stasis possibly triggered by sub-optimal SERCA activity that could contribute to the distal axonopathy observed in diabetes

Inhibiting heat-shock protein 90 reverses sensory hypoalgesia in diabetic mice

Increasing the expression of Hsp70 (heat-shock protein 70) can inhibit sensory neuron degeneration after axotomy. Since the onset of DPN (diabetic peripheral neuropathy) is associated with the gradual decline of sensory neuron function, we evaluated whether increasing Hsp70 was sufficient to improve several indices of neuronal function. Hsp90 is the master regulator of the heat-shock response and its inhibition can up-regulate Hsp70. KU-32 (N-{7-[(2R,3R,4S,5R)-3,4-dihydroxy-5-methoxy-6,6-dimethyl-tetrahydro-2H-pyran-2-yloxy]-8-methyl-2-oxo-2H-chromen-3-yl}acetamide) was developed as a novel, novobiocin-based, C-terminal inhibitor of Hsp90 whose ability to increase Hsp70 expression is linked to the presence of an acetamide substitution of the prenylated benzamide moiety of novobiocin. KU-32 protected against glucose-induced death of embryonic DRG (dorsal root ganglia) neurons cultured for 3 days in vitro. Similarly, KU-32 significantly decreased neuregulin 1-induced degeneration of myelinated Schwann cell DRG neuron co-cultures prepared from WT (wild-type) mice. This protection was lost if the co-cultures were prepared from Hsp70.1 and Hsp70.3 KO (knockout) mice. KU-32 is readily bioavailable and was administered once a week for 6 weeks at a dose of 20 mg/kg to WT and Hsp70 KO mice that had been rendered diabetic with streptozotocin for 12 weeks. After 12 weeks of diabetes, both WT and Hsp70 KO mice developed deficits in NCV (nerve conduction velocity) and a sensory hypoalgesia. Although KU-32 did not improve glucose levels, HbA1c (glycated haemoglobin) or insulin levels, it reversed the NCV and sensory deficits in WT but not Hsp70 KO mice. These studies provide the first evidence that targeting molecular chaperones reverses the sensory hypoalgesia associated with DPN

The effect of 5-aminolevulinic acid on cytochrome c oxidase activity in mouse liver

<p>Abstract</p> <p>Background</p> <p>5-Aminolevulinic acid (ALA) is a precursor of heme that is fundamentally important in aerobic energy metabolism. Among the enzymes involved in aerobic energy metabolism, cytochrome <it>c </it>oxidase (COX) is crucial. In this study, the effect of ALA on cytochrome <it>c </it>oxidase activity was measured.</p> <p>Findings</p> <p>c57BL/6N species of mice were administered ALA orally for 15 weeks. After ALA administration, mice were sacrificed and livers were obtained. COX activity in mitochondria from ALA-administered mouse livers was 1.5-fold higher than that in mitochondria from PBS-administered mouse livers (P < 0.05). Furthermore, ATP levels in ALA-administered mouse livers were much higher than those in PBS-administered mouse livers. These data suggest that oral administration of ALA promotes aerobic energy metabolism, especially COX activity.</p> <p>Conclusions</p> <p>This is the first report of a drug that functions in aerobic energy metabolism directly. Since COX activity is decreased in various diseases and aging, the pharmacological effects of ALA will be expanding.</p