Treatment of vanadium(V) oxide with an ethanol-concentrated sulfuric acid mixture, followed by the addition of an equimolar amount of beta-alanine and sodium hydroxide, and finally raising the pH to 3.9 with sodium carbonate solution, under continuous heating in a water bath and in the presence of air, leads to the polyionic sodium cyclo-[mu(6)-(sulfato-O,O',O'')tris[mu-(beta-alanine-O,O')-mu-oxo]tris(mu-hydroxo-mu-oxo)hexa[oxovanadium(V)]] sulfate tridecahydrate which crystallizes in the monoclinic P2(1)/n space group [a = 9.5192(4), b = 20.1185(9), c = 22.6174(9) A, beta = 97.011(1) degrees; Z = 4]. The crown-shaped polyoxovanadium(V) cluster cation, with carboxylate-bridging amino acid ligands, has an Anderson structure with two unique capping sulfato ligands. Its structural analysis, together with IR, UV-vis, and preliminary data on its solution properties, is presented.
Fine grinding of high purity talc in jet mill at low grinding pressure was carried out by varying the feed rate and classifier rotational speed. These ground particles were sonicated in laboratory ultrasonic bath by varying the soniction period at five levels. The ground and sonicated particles were characterized in terms of particle size and particle size distribution. Mechanochemical and sonochemical effect of talc was determine via X-ray diffraction. Particle shape and surface texture of the ground and sonicated product was determined via scanning electron microscope and transmission electron microscope. The ground particle size exhibited particle size below 10 µm with narrow size distribution. The reduction of peak intensity in (002) plane indicated the layered structure has been distorted. The sonicated talc shows that the thickness of the talc particles after the sonication process is 20 nm but the lateral particle size still remains in micron range. The reduction of the XRD peak intensity for (002) plane and thickness of sonicated talc as shown in SEM and TEM micrographs proves that fine grinding and sonication process produces talc nanosheets.
The peels of pomelo contribute 30% of the fruit weight and yet it has been dump without recognizing the possible nutritional value of the peels. Study has been carried out to identify flavonoid content of the peels and analysed the activity of the flavonoid towards inhibition of lipid peroxidation. Optimization of flavonoid extraction was conducted using aqueous solvent (methanol and ethanol), extraction time (1-3 h) and extraction temperature (50°C-80°) via water bath extraction. The total content of flavonoids was quantitatively determined by using coloration methods with chromogenic system of NaNO2–Al (NO3)3–NaOH and and it was found that the extraction at 65ºC for 2 h in aqueous ethanol was the optimized condition for maximum flavonoids i.e. 190.42mg/L. A spectrophometric analysis was performed to evaluate flavonoid activity towards lipid peroxidation in the fish tissue. There was reduction in Peroxide value (PV) indicated the inhibition of lipid peroxidation in fish treated with pomelo peel as evidence of concurrency of positive flavonoid activity.
Austempering is one of the trendiest heat treatment processes to promote the strength and toughness of ductile iron. However, such practice is complex because it involves using aqueous solutions as quenchant (salt bath solution). This study was conducted to analyse the heat treatment of the combination processes of annealing-austenitising and evaluate the correlation between microstructure constituent and hardness of the ductile iron. Ductile iron samples in form of double cylinder was produced by conventional CO2 sand casting method. The new heat treatment process was started by annealed at 873 K for 1.8 ks before being oil quenched. Subsequently, the samples were austenitised at austenitising temperatures 1123 K, 1173 K and 1223 K for 3.6 ks respectively before being immediately oil quenched to room temperature. A series of microstructure analysis tests, including optical microscopy and X-ray diffraction (XRD) was applied. Vickers microhardness tester was used to measure the hardness for each microstructure constituent. The results showed that ductile iron matrix transforms to martensitic during heat treatment of annealing-austenitising combination processes, which in turn contributes to increasing microhardness of martensite and the bulk hardness of ductile iron.
Lignosus rhinocerotis has a long history of use by the indigenous community within East Asia to treat a range of health conditions including asthma and chronic cough. To date, there is limited scientific evidence to support its therapeutic effects in relieving these airways conditions. In this study, we examined the effects of the different molecular weight fractions [high-molecular-weight (HMW), medium-molecular-weight (MMW), and low-molecular-weight (LMW)] obtained from the cold water sclerotial extract (CWE) of L. rhinocerotis on airways patency using airway segments isolated from Sprague Dawley rat in an organ bath set-up. It is demonstrated that the HMW and MMW fractions exhibited higher efficacy in relaxing the pre-contracted airways when compared to the CWE and LMW fraction. In addition, the HMW fraction markedly supressed carbachol-, 5-hydroxytrptamine-, and calcium-induced airway contractions. CWE demonstrated a lower efficacy than the HMW fraction but it also significantly attenuated carbachol- and calcium-induced airway contractions. Results showed that the bronchorelaxation effect of CWE and fractions is mediated via blockade of extracellular Ca2+ influx. The composition analysis revealed the following parts of carbohydrate and proteins, respectively: HMW fraction: 71 and 4%; MMW fraction: 35 and 1%; and LMW fraction: 22 and 0.3%. Our results strongly suggest that the polysaccharide-protein complex or proteins found in the HMW and MMW fractions is likely to contribute to the bronchorelaxation effect of CWE.
This article describes the preparation of titanium dioxide (TiO2) hollow fiber membrane using phase inversion and sintering technique. In this study, nano-sized TiO2 powders with different particle sizes were used to prepare ceramic hollow fiber membranes. In a series of preparation steps, a dispersant was dissolved in organic solvent before the addition of ceramic powders. These steps were followed by the addition of polymer binder. The membrane precursor was obtained by extruding the ceramic suspension into a coagulation bath, which enabled the precipitation of the precursor of ceramic hollow fiber membrane. The dried precursor was later sintered at temperatures ranging from 1200 to 1300oC to obtain TiO2 hollow fiber membrane. Scanning electron microscopy (SEM) was used to study the morphology of TiO2 hollow fiber membrane. The SEM images show the membrane can be shaped into asymmetric structure and symmetric structure based on the ceramic suspension compositions. The highest mechanical strength obtained was 223 MPa when the membrane prepared using 20 wt. % ceramic loading of single nano-sized powder and sintered at 1300oC. TiO2 hollow fiber membrane prepared using similar ceramic loading showed high permeation rate of inert gas. High pure water fluxes were obtained when permeability tests was carried out using TiO2 hollow fiber membrane, prepared using mixture of nano-sized particles, even though its cross-section have a sponge-like structure.
Schistosomiasis is the major source of morbidity in Sub-Saharan Africa and Asia. It is estimated that 207 million people are infected, of which 97% are in Africa. The aim of this study was the determining of prevalence as well as the phylogeny of S. haematobium among school children in Argungu Emirate, Kebbi State Nigeria. A total of 325 urine samples was collected from school children between 7 to 14 years. S. heamatobium eggs was examined under dissecting microscope and DNA was extracted from urine sample and COX1 gene was amplified by nested PCR. The PCR products were purified, sequenced and analysed. This study showed a prevalence of 32.09%, with male pupils having the highest prevalence. S. haematobium infections in children who fetch water in the river have 24 times higher risk of being infected while those who bath in the river have 158 times higher risk of being infected. Our sequences were phylogenetically related to S. haematobium isolate U82266 from Kenya and consistence with the predominant species in Africa. This was the first S. haematobium and S. mansoni co-infection reported in Nigeria. S. haematobium infection is prevalent among school age and significantly associated with water contact.
Miniaturization of electronic devices has led to the development of 3D IC packages which require ultra-small-scale interconnections. Such small interconnects can be completely converted into Cu-Sn based intermetallic compounds (IMCs) after reflow. In an effort to improve IMC based interconnects, an attempt is made to add Ni to Cu-Sn-based IMCs. Multilayer interconnects consisting of stacks of Cu/Sn/Cu/Sn/Cu or Cu/Ni/Sn/Ni/Sn/Cu/Ni/Sn/Ni/Cu with Ni = 35 nm, 70 nm, and 150 nm were electrodeposited sequentially using copper pyrophosphate, tin methanesulfonic, and nickel Watts baths, respectively. These multilayer interconnects were investigated under room temperature aging conditions and for solid-liquid reactions, where the samples were subjected to 250 °C reflow for 60 s and also 300 °C for 3600 s. The progress of the reaction in the multilayers was monitored by using X-ray Diffraction, Scanning Electron Microscope, and Energy dispersive X-ray Spectroscopy. FIB-milled samples were also prepared for investigation under room temperature aging conditions. Results show that by inserting a 70 nanometres thick Ni layer between copper and tin, premature reaction between Cu and Sn at room temperature can be avoided. During short reflow, the addition of Ni suppresses formation of Cu₃Sn IMC. With increasing Ni thickness, Cu consumption is decreased and Ni starts acting as a barrier layer. On the other hand, during long reflow, two types of IMC were found in the Cu/Ni/Sn samples which are the (Cu,Ni)₆Sn₅ and (Cu,Ni)₃Sn, respectively. Details of the reaction sequence and mechanisms are discussed.
This is a study of 13 Malaysian patients with clinically definite Multiple sclerosis (MS) subjected to a hot bath test with VEPs, BAEPs, median nerve SSEPs before and after heating. Five patients (38%) developed neurological changes with the rise in body temperature. There was an average of 0.46 new sign per patient. Four patients had motor disturbances attributed mainly to aggravation of spinal cord dysfunction. Two patients had additional visual deterioration, one patient has associated VEP change. This study shows that though Uhthoff's phenomenon has not been noted in the reports of Asian MS patients, when subjected to rigorous testing, Asian MS patients also show sensitivity to body temperature change. However, the percentage of positivity of the hot bath test is much lower than that reported for Caucasians. Thus this study shows further differences between Asian and Caucasian MS patients.
The general notion of activation of Gq-protein coupled receptors (GPCR) involves the mobilisation of stored and extracellular calcium and leads to smooth muscle tissue contraction. The aim of this study was to investigate the involvement of calcium mediated contractions in vascular and airway smooth muscles. Using standard organ bath procedures, aortic and tracheal rings were obtained from 6 to 8 week-old male Sprague Dawley rats. To activate the Gq protein receptors, phenylephrine (PE), an α1-adrenoceptor agonist, and carbachol, a M3 cholinoceptor agonist was added to baths containing the aortic and tracheal rings, respectively. The maximum response (Emax) to PE was reduced from 158.8 ± 11.8% (n=6) to 62.5 ± 12.4 % (n=8) upon removal of extracellular calcium in Krebs-Ringer solution. Maximal response to PE was also suppressed in the presence of nifedipine, a L-type Ca2+ channel inhibitor, (70.3 ± 11 %, n=8) and SKF96365, a canonical transient receptor potential cation channel inhibitor, (26.7 ± 13.2 %, n=5) when the influx of extracellular calcium was blocked. Removal of stored calcium also attenuated the PE contraction (p0.05). From these observations, we conclude that the role of stored and extracellular calcium in Gq protein activation is not the same across different types of smooth muscle tissues.
Incorporation of silver nanomaterial into polymer matrix can further accomplished their potential usage in real life
applications. In our previous study, silver nanoparticles (AgNPs) and silver-graphene oxide nanocomposites (AgGO)
were prepared via a rapid microwave-assisted method. Hereby, the as-synthesized AgNPs or AgGO was dispersed in a
chitosan solution. Subsequently, the resultant mixture solution was further coagulated in a coagulation bath containing
sodium hydroxide via a neutralization process. This resulted in the formation of spherical-shaped chitosan beads.
The structure of the beads showed that the chitosan beads embedded with AgGO exhibited a more porous structure as
compared to the plain chitosan beads. Furthermore, the chitosan beads containing AgNPs or AgGO were tested for
their antibacterial activity against Escherichia coli and Staphylococcus aureus. The antibacterial results indicated that
the silver nanomaterial contained chitosan beads could effectively inhibit the growth of both E. coli and S. aureus as
compared to the bare chitosan beads. The produced chitosan nanocomposite envisioned that can be potentially employed
for water disinfection purpose.
This study describes the development of a rapid and sensitive Loop-mediated isothermal
amplification assay for detection of swine DNA in adulterated meat and meat products. The
need to protect consumer’s right to eat foods of their choices, has made it imperative for
researchers to develop efficient means of screening and certification of food products. Six sets
of LAMP primers designed based on porcine tRNA lysine gene and ATPase subunit 8 genes
were used for the assay. Amplification was carried out under constant temperature (630C), using
a simple laboratory water bath. Average time spent in amplification and detection of results was
25 min. All results were visually detected and confirmed by electrophoresis. Detection limit of
the assay was 0.03 femtogram (fg) much high than the PCR assay, and detection probability of
the assay was 100%. Detection of 0.5% of pork spiked with 99.5% of cattle beef is indicative
of the sensitivity and robustness of the assay. This could serve as a prototype for development
of a sensitive and inexpensive Swine DNA LAMP detection kit.