60 research outputs found
Suitability of Nafada Gypsum for the Production of Jute Fibre Reinforced Plasterboards
High demand for Plaster of Paris (POP) in the Nigeria building industry, particularly within the north-east geopolitical zone has made local procurement of the raw gypsum inevitable. The study was conducted to evaluate the characteristics of gypsum from Nafada mining site, one of the northeast rich gypsum deposits with an estimated reserve of 751,728.00 metric tons. Sample of gypsum from the site was obtained and its physical and chemical properties were determined. It was calcined into POP in an oven between 115o C (240o F) and 200o C (392oF). The ratio of water: plaster was adopted as 200ml/400g with impact resistance as 7.9mm and flexural strength as 4.72N/mm2. Absorption tests were carried out to ascertain the viability of the mineral in POP production. 0.5% of sisal fiber showed lower rate of 25.4% water absorbency. The result confirmed that Nafada gypsum is suitable for the production of POP for use in plasterboards, with jute fibre as reinforcing material.Key words: Nafada gypsum; Plaster of Paris; Building
Co-pyrolysis of Rice Husk with Underutilized Biomass Species: A Sustainable Route for Production of Precursors for Fuels and Valuable Chemicals
In this study, co-pyrolysis of rice husk with
underutilized biomass, Napier grass and sago waste was
carried out in a fixed bed reactor at 600 �C, 30 �C/min and
5 L/min nitrogen flowrate. Two-phase bio-oil (organic and
aqueous) was collected and characterized using standard
analytical techniques. 34.13–45.55 wt% total boil-oil yield
was recorded using assorted biomass compared to pure risk
husk biomass with 31.51 wt% yield. The organic phase
consist mainly benzene derivatives with higher proportion
in the oil from the co-pyrolysis process relative to the
organic phase from the pyrolysis of the individual biomass
while the aqueous phase in all cases was predominantly
water, acids, ketones, aldehydes, sugars and traces of
phenolics. This study has demonstrated a good approach
towards increasing valorization of rice husk in a single
reaction step for the production of high grade bio-oil,
which can be transformed into fuel and valuable chemicals
Development, Optimisation, Validation and Inter-Laboratory Verification of a Reversed Phase HPLC Method for Quantification of Human Recombinant Insulin
HPLC methods for insulin in official monographs require extended runtimes and elevated temperatures. Inter-laboratory reproducibility of HPLC methods obtained from published literature is an on-going challenge, moreso for peptides. This paper serves as a step-by step guide to troubleshoot and establish a validated HPLC method for insulin at room temperature using simple UV detectors with minimal run times. A modified gradient reversed-phase HPLC was developed for the quantification of recombinant human insulin with UV detection at room temperature. An octadecylsilica column was used as the stationary phase while the mobile phase consisted of solution A: 1mmol sodium sulphate and 0.2% triethylamine in water and solution B: acetonitrile. The developed method was then validated using International Conference on Harmonisation (ICH) guidelines. The calibration curve was linear over a concentration range of 10-1000 μg/mL with correlation coefficient of 0.9993, with average recovery percent of 100.89 ± 1.4% and RSD recovery of 0.01. Insulin retention time was 3.84 ± 0.08 mins, while LOD and LOQ were estimated at 0.63 and 2.0 μg/mL respectively. The developed method conformed to the validation criteria of the ICH guidelines in our laboratories and other independent operator laboratories, and can serve as a rapid and effective method for quantifying insulin from any sample at room temperature using simple detectors
In-situ upgrading of Napier grass pyrolysis vapour over microporous and hierarchical mesoporous zeolites
This study presents in-situ upgrading of pyrolysis
vapour derived from Napier grass over microporous and
mesoporous ZSM-5 catalysts. It evaluates effect of process
variables such catalyst–biomass ratio and catalyst type in
a vertical fixed bed pyrolysis system at 600 °C, 50 °C/min
under 5 L/min nitrogen flow. Increasing catalyst–biomass
ratio during the catalytic process with microporous structure
reduced production of organic phase bio-oil by approximately
7.0 wt%. Using mesoporous catalyst promoted
nearly 4.0 wt% higher organic yield relative to microporous
catalyst, which translate to only about 3.0 wt% reduction
in organic phase compared to the yield of organic phase
from non-catalytic process. GC–MS analysis of bio-oil
organic phase revealed maximum degree of deoxygenation
of about 36.9% with microporous catalyst compared to
the mesoporous catalysts, which had between 39 and 43%.
Mesoporous catalysts promoted production olefins and
alkanes, normal phenol, monoaromatic hydrocarbons while
microporous catalyst favoured the production of alkenes
and polyaromatic hydrocarbons. There was no significant increase in the production of normal phenols over microporous catalyst due to its inability to transform the methoxyphenols and methoxy aromatics. This study demonstrated that upgrading of Napier grass pyrolysis vapour over mesoporous ZSM-5 produced bio-oil with improved physicochemical properties
Dry powder inhalation of macromolecules using novel PEG-co-polyester microparticle carriers
This study investigated optimizing the formulation parameters for encapsulation of a model mucinolytic enzyme, α-chymotrypsin (α-CH), within a novel polymer; poly(ethylene glycol)-co-poly(glycerol adipate-co-ω-pentadecalactone), PEG-co-(PGA-co-PDL) which were then applied to the formulation of DNase I. α-CH or DNase I loaded microparticles were prepared via spray drying from double emulsion (w1/o/w2) utilizing chloroform (CHF) as the organic solvent, l-leucine as a dispersibility enhancer and an internal aqueous phase (w1) containing PEG4500 or Pluronic® F-68 (PLF68). α-CH released from microparticles was investigated for bioactivity using the azocasein assay and the mucinolytic activity was assessed utilizing the degradation of mucin suspension assay. The chemical structure of PEG-co-(PGA-co-PDL) was characterized by 1H NMR and FT-IR with both analyses confirming PEG incorporated into the polymer backbone, and any unreacted units removed. Optimum formulation α-CH-CHF/PLF68, 1% produced the highest bioactivity, enzyme encapsulation (20.08 ± 3.91%), loading (22.31 ± 4.34 μg/mg), FPF (fine particle fraction) (37.63 ± 0.97%); FPD (fine particle dose) (179.88 ± 9.43 μg), MMAD (mass median aerodynamic diameter) (2.95 ± 1.61 μm), and the mucinolytic activity was equal to the native non-encapsulated enzyme up to 5 h. DNase I-CHF/PLF68, 1% resulted in enzyme encapsulation (17.44 ± 3.11%), loading (19.31 ± 3.27 μg/mg) and activity (81.9 ± 2.7%). The results indicate PEG-co-(PGA-co-PDL) can be considered as a potential biodegradable polymer carrier for dry powder inhalation of macromolecules for treatment of local pulmonary diseases
An Integrative Phenotype-Genotype Approach Using Phenotypic Characteristics from the UAE National Diabetes Study Identifies HSD17B12 as a Candidate Gene for Obesity and Type 2 Diabetes
The United Arab Emirates National Diabetes and Lifestyle Study (UAEDIAB) has identified obesity, hypertension, obstructive sleep apnea, and dyslipidemia as common phenotypic characteristics correlated with diabetes mellitus status. As these phenotypes are usually linked with genetic variants, we hypothesized that these phenotypes share single nucleotide polymorphism (SNP)-clusters that can be used to identify causal genes for diabetes. We explored the National Human Genome Research Institute-European Bioinformatics Institute Catalog of Published Genome-Wide Association Studies (NHGRI-EBI GWAS) to list SNPs with documented association with the UAEDIAB-phenotypes as well as diabetes. The shared chromosomal regions affected by SNPs were identified, intersected, and searched for Enriched Ontology Clustering. The potential SNP-clusters were validated using targeted DNA next-generation sequencing (NGS) in two Emirati diabetic patients. RNA sequencing from human pancreatic islets was used to study the expression of identified genes in diabetic and non-diabetic donors. Eight chromosomal regions containing 46 SNPs were identified in at least four out of the five UAEDIAB-phenotypes. A list of 34 genes was shown to be affected by those SNPs. Targeted NGS from two Emirati patients confirmed that the identified genes have similar SNP-clusters. ASAH1, LRP4, FES, and HSD17B12 genes showed the highest SNPs rate among the identified genes. RNA-seq analysis revealed high expression levels of HSD17B12 in human islets and to be upregulated in type 2 diabetes (T2D) donors. Our integrative phenotype-genotype approach is a novel, simple, and powerful tool to identify clinically relevant potential biomarkers in diabetes. HSD17B12 is a novel candidate gene for pancreatic β-cell function
Cetuximab Conjugated with Octreotide and Entrapped Calcium Alginate-beads for Targeting Somatostatin Receptors.
There is a need to formulate oral cetuximab (CTX) for targeting colorectal cancer, which is reported to express somatostatin receptors (SSTRs). Therefore, coating CTX with a somatostatin analogue such as octreotide (OCT) is beneficial. Alginate was used to coat CTX to facilitate delivery to the gastrointestinal tract (GIT). This study aimed to deliver CTX conjugated with OCT in the form of microparticles as a GIT-targeted SSTR therapy. Both CTX and OCT were conjugated using a solvent evaporation method and the conjugated CTX-OCT was then loaded onto Ca-alginate-beads (CTX-OCT-Alg), which were characterized for drug interactions using differential scanning calorimetry (DSC), and Fourier transform infrared spectra (FTIR). Moreover, the morphology of formulated beads was examined using a scanning electron microscope (SEM). The drug content and release profile were studied using UV spectroscopy. Finally, in vitro cytotoxicity of all compounds was evaluated. The results showed homogenous conjugated CTX-OCT with a diameter of 0.4 mm. DSC showed a delay in the OCT peak that appeared after 200 °C due to small polymer interaction that shifted the OCT peak. Moreover, FTIR showed no prominent interaction. SEM showed clear empty cavities in the plain Ca-alginate-beads, while CTX-OCT-Alg showed occupied beads without cavities. CTX-OCT-Alg had a negligible release in 0.1 N HCl, while the CTX-OCT was completely released after 300 min in phosphate buffer pH 7.4. All formulations showed good antiproliferative activity compared with free drugs. The formulated CTX-OCT-Alg are a promising platform for targeting colorectal cancer through GIT
Effects of pretreatments of Napier Grass with deionized water, sulfuric acid and sodium hydroxide on pyrolysis oil characteristics
The depletion of fossil fuel reserves has led to
increasing interest in liquid bio-fuel from renewable biomass. Biomass is a complex organic material consisting of
different degrees of cellulose, hemicellulose, lignin,
extractives and minerals. Some of the mineral elements
tend to retard conversions, yield and selectivity during
pyrolysis processing. This study is focused on the extraction of mineral retardants from Napier grass using deionized water, dilute sodium hydroxide and sulfuric acid and subsequent pyrolysis in a fixed bed reactor. The raw biomass was characterized before and after each pretreatment
following standard procedure. Pyrolysis study was conducted
in a fixed bed reactor at 600 o�C, 30 �C/min and 30 mL/min N2 flow. Pyrolysis oil (bio-oil) collected was analyzed using standard analytic techniques. The bio-oil yield and characteristics from each pretreated sample were compared with oil from the non-pretreated sample. Bio-oil
yield from the raw sample was 32.06 wt% compared to
38.71, 33.28 and 29.27 wt% oil yield recorded from the
sample pretreated with sulfuric acid, deionized water and
sodium hydroxide respectively. GC–MS analysis of the oil
samples revealed that the oil from all the pretreated biomass had more value added chemicals and less ketones and
aldehydes. Pretreatment with neutral solvent generated
valuable leachate, showed significant impact on the ash
extraction, pyrolysis oil yield, and its composition and
therefore can be regarded as more appropriate for thermochemical conversion of Napier grass
Smart Injectable Chitosan Hydrogels Loaded with 5-Fluorouracil for the Treatment of Breast Cancer
The treatment of breast cancer requires long chemotherapy management, which is accompanied by severe side effects. Localized delivery of anticancer drugs helps to increase the drug concentration at the site of action and overcome such a problem. In the present study, chitosan hydrogel was prepared for local delivery of 5-Fluorouracil. The in vitro release behavior was investigated and the anticancer activity was evaluated against MCF-7 cells using MTT assay. The in vivo studies were investigated via intra-tumoral injection of a 5-FU loaded hydrogel into breast cancer of female rats. The results indicated that the modified hydrogel has excellent physicochemical properties with a sustained in vitro release profile matching a zero-order kinetic for one month. In addition, the hydrogel showed superior inhibition of cell viability compared with the untreated control group. Moreover, the in vivo studies resulted in antitumor activity with minor side effects. The tumor volume and level of tumor markers in blood were inhibited significantly by applying the hydrogel compared with the untreated control group. In conclusion, the designed injectable hydrogels are potential drug delivery systems for the treatment of breast cancer with a controlled drug release profile, which could be suitable for decreasing the side effects of chemotherapy agents
Corrosion Resistance of AA6063-Type Al-Mg-Si Alloy by Silicon Carbide in Sodium Chloride Solution for Marine Application
The present work focused on corrosion inhibition of
AA6063 type Al-Mg-Si alloy in sodium chloride (NaCl) solution
with a silicon carbide inhibitor, using the potentiodynamic
electrochemical method. The aluminium alloy surface morphology
was examined, in the as-received and as-corroded in the
un-inhibited state, with scanning electron microscopy equipped
with energy dispersive spectroscopy (SEM-EDS). The results
obtained via linear polarization indicated a high corrosion potential
for the unprotected as-received alloy. Equally, inhibition efficiency
as high as 98.82% at 10.0 g/v silicon carbide addition was obtained
with increased polarization resistance (Rp), while the current
density reduced significantly for inhibited samples compared to the
un-inhibited aluminium alloy. The adsorption mechanism of the
inhibitor aluminium alloy follows the Langmuir adsorption
isotherm. This shows that the corrosion rate of aluminium alloy
with silicon carbide in NaCl environment decreased significantly
with addition of the inhibito
- …