351 research outputs found
Pre-concentration of toxic metals using electrospun amino-functionalized nylon-6 nanofibre sorbent
This paper presents a new approach for pre-concentrating toxic metals (As, Cd, Ni and Pb) in aqueous environments using an amino-functionalized electrospun nanofibre sorbent. The sorbent, composed of nanofibres of average diameter 80 ± 10 nm and specific surface area of 58m2 g–1, exhibited fast adsorption kinetics ( adsorption (0.34)>HNO3+H2O2 (0.23) digestion.Asimilar trend was observed for Ni in river water as well as Ni andCdin tap water samples. Pb ions in the river water samples were pre-concentrated slightly better using the two digestion methods pre-concentration factors ~22) compared to adsorption method (pre-concentration factor ~21). The use of the electrospun amino-functionalized nanofibre sorbent presentsanefficientand cost-effective alternative for pre-concentration of toxic metals inaqueousenvironments
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Magnetic Resonance Imaging Pilot Study of Intravenous Glyburide in Traumatic Brain Injury.
Pre-clinical studies of traumatic brain injury (TBI) show that glyburide reduces edema and hemorrhagic progression of contusions. We conducted a small Phase II, three-institution, randomized placebo-controlled trial of subjects with TBI to assess the safety and efficacy of intravenous (IV) glyburide. Twenty-eight subjects were randomized and underwent a 72-h infusion of IV glyburide or placebo, beginning within 10 h of trauma. Of the 28 subjects, 25 had Glasgow Coma Scale (GCS) scores of 6-10, and 14 had contusions. There were no differences in adverse events (AEs) or severe adverse events (ASEs) between groups. The magnetic resonance imaging (MRI) percent change at 72-168 h from screening/baseline was compared between the glyburide and placebo groups. Analysis of contusions (7 per group) showed that lesion volumes (hemorrhage plus edema) increased 1036% with placebo versus 136% with glyburide (p = 0.15), and that hemorrhage volumes increased 11.6% with placebo but decreased 29.6% with glyburide (p = 0.62). Three diffusion MRI measures of edema were quantified: mean diffusivity (MD), free water (FW), and tissue MD (MDt), corresponding to overall, extracellular, and intracellular water, respectively. The percent change with time for each measure was compared in lesions (n = 14) versus uninjured white matter (n = 24) in subjects receiving placebo (n = 20) or glyburide (n = 18). For placebo, the percent change in lesions for all three measures was significantly different compared with uninjured white matter (analysis of variance [ANOVA], p < 0.02), consistent with worsening of edema in untreated contusions. In contrast, for glyburide, the percent change in lesions for all three measures was not significantly different compared with uninjured white matter. Further study of IV glyburide in contusion TBI is warranted
Label-free quantitative comparison of cerebrospinal fluid glycoproteins and endogenous peptides in subjects with Alzheimer's disease, mild cognitive impairment, and healthy individuals
PURPOSE:
The goal of this study is to investigate putative molecular dynamic changes in cerebrospinal fluids (CSFs) collected from individuals with mild cognitive impairment (MCI) and Alzheimer's disease (AD) as compared to healthy controls.
EXPERIMENTAL DESIGN:
The CSF samples from 12 subjects comprised of four cognitively normal individuals and eight patients with MCI and AD, respectively. Two aliquots of each CSF samples (total 1 mL) of each participant are used for this study. Endogenous peptide separations are performed using 10 000 molecular weight cut-off filters followed by LC-MS/MS identification and quantitation while lectin-enrichment chromatography is used to enrich glycoproteins in CSF followed by trypsin digestion and subsequent LC-MS/MS for shotgun identification and label-free quantitation.
RESULTS:
Using an optimized submicrogram peptide separation with molecular weight cut-off filtration and an in house-constructed database, 645 peptides are identified. Glycoproteins are enriched by lectin affinity chromatography, resulting in 795 identified proteins. The discovery and alterations of proSAAS-derived peptides and transthyretin are described and their roles in AD are discussed.
CONCLUSIONS AND CLINICAL RELEVANCE:
Comprehensive identification of endogenous CSF peptidome is achieved. Fifteen proteins are found to be differentially expressed among the three groups. The dynamic changes of transthyretin are reported for the first time
Investigating the cyclic breaking of butyl-, methyland ethyl-biodiesel from waste vegetable oil using ultraviolet-visible spectrophotometry
The main advantage of biodiesel to fossil-diesel is attributed to the
ester functional group in its structure. Many researchers have affirmed that the
functional group assists the diesel engine to function at its peak. However, the efficiency
of the biodiesel to keep the mechanical piston-strokes in the diesel engine
is experimentally presumed low especially if the engine works for a long time. In
this research, it was proposed that the cyclic break down of the ester functional
group of biodiesel is a major disadvantage. Butanol, ethanol and methanol biodiesel
were produced in the laboratory using waste vegetable oil from restaurant.
The Ultraviolet-visible spectroscopy or spectrophotometer (UV–Vis) was used
to investigate the cyclic break down in the Butyl-, Methyl- and Ethyl- biodiesel.
The Ultraviolet-visible spectroscopy or spectrophotometer (UV–Vis) was used
to probe the various biodiesel samples with a start and stop wavelength of 500
and 900 nm respectively. The wavelength interval was 1 nm at a high scanning
speed. Between 500–550 and 800–850 nm, the Ethyl- and Butyl- biodiesel had an
absorbance
of 2.7 and 1.6 respectively with 3 peaks each. Methyl-biodiesel had
the highest absorbance of 1.7 at 600–650 nm with 1 peak. The computational
extrapolation of all outcomes affirms that cyclic breaking is highest in Butylbiodiesel.
The most resilient biodiesel type was the Ethyl-biodiesel. However,
it was recommended that cyclic breaking may be preserved by ratio-mixing of
biodiesel
with fossil-diesel
Screening of Locally Available Lemon Grass (Cymbopogon citratus) for Repellency Action against Aedes aegypti
In Nigeria, re-emergence of diseases caused by Aedes mosquito borne pathogens, and challenges associated with existing control tools occur. This necessitates an improved insecticide-based tool for use in Integrated Vector Management. So, repellent action of Cymbopogon citratus essential oil (EO) on Aedes aegypti (Linn.) was tested. The EO from C. citratus plant sourced from Awka, was extracted by hydro distillation, and the phytochemicals analyzed by Gas Chromatography-Mass Spectrometry. Repellent action of the EO on unfed Ae. aegypti was assessed using "WHO arm-in-cage" method. In triplicate, arms of human volunteers were treated with different concentrations (50.0, 25.0, 12.5, 6.25 and 3.125 % v/v) of the EO and submitted to 25-caged, unfed Ae. aegypti for 1 minute in every 30 minutes. β-cedrenes, kaempferol, and thujopsene dominated the 13 phytochemicals identified. The standard (Odomos®) and all EO concentrations recorded 100 % repellency on application. At 30 minutes, EC99.9 value was25.0 %, concentrations ≥ 62.5 % v/v gave 100 % repellency (p > 0.05). At 60 minutes, EC99.9 value was 30.68 %, concentrations ≥ 12.5 % v/v gave 100 % repellency (p > 0.05). At 90 to 120 minutes, 50 % concentration maintained 100 % repellency (p < 0.05), EC99.9 value was 48.79 % at 120 minutes. Recording 120 minutes protection time with no adverse effect, 50 % concentration showed equal potency as Odomos®. Research to isolate the active ingredients in the EO for incorporation into beneficial health and economic products is desirable.
Preliminary screening of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCDD) and tetrabromobisphenol A (TBBPA) flame retardants in landfill leachate
The occurrence of selected brominated flame retardants, including nine polybrominated diphenyl ether (PBDE) congeners, hexabromocyclododecane (HBCDD) and tetrabromobisphenol A (TBBPA) in leachate samples from eight landfill sites in South Africa, were investigated. In addition, the possible influences of dissolved organic carbon on their levels were also evaluated. Filtered leachate samples were subjected to solid-phase extraction to isolate the various target compounds. PBDEs with six bromine substituents and above, as well as α-HBCDD, β-HBCDD and TBBPA, were generally found below the detection limit. However, the mean value of the total lower PBDE congeners ranged between 0.04 and 0.48 μg L−1, and the concentrations of γ-HBCDD ranged from not detectable (ND) to 0.05 μg L−1. No significant correlation was observed between the target compounds and dissolved organic carbon, although weak to moderate correlations were mostly observed for the lower PBDEs.https://link.springer.com/journal/106612018-08-30hj2017Chemistr
Activated carbon from lignocellulosic waste residues: effect of activating agent on porosity characteristics and use as adsorbents for organic species
This paper reports on the effect of activating agents such as the impregnation ratio of phosphoric acid (1:1–1:5) at constant activation temperature on the performance of porous activated carbon from waste residues (maize tassel). The variation in the impregnation ratio of the produced activated carbon (AC) from 1:1 to 1:5 enabled the preparation of a high surface area (1,263 m2/g) and a large pore volume (1.592 cm3/g) of AC produced from maize tassel (MT) using a convectional chemical activating agent (phosphoric acid). Impregnation ratios (IR) of the precursors were varied between 1:1 and 1:5 in which it was found that the ratio of 1:4 was optimal based on the high surface area, while 1:5 has the optimal pore volume value for the produced activated carbon
Evaluating the Drying Characteristics of Paddy Rice Using Superheated Steam Dryer
It has been recorded in literature that superheated steam has the ability to
combine the parboiling operation (steaming and drying) of paddy (Oryza
sativa - UPL1) rice into a single unit. According to literature, this process has
not been fully explored and implemented in rice processing. In this research
work, superheated steam dryer was used to parboil (steam and dry) paddy
rice. Soaking time and temperature used was 12hours at 60o
C, with steaming
time ranging from 10 to 24mins, while the drying conditions used were;
temperature (160, 170 and 180o
C), bed depth (1, 3 and 5cm) and tempering
time (20 and 40 minutes). In addition, paddy rice was dried from initial
moisture content ranging from 26-43% (d.b) to a final moisture content of 2 –
8% (d.b). It was observed that the milled rice yield ranged from 71.32 to
94.5%, head rice yield ranged from 70.5 and 90.6%, broken rice ranged from
3.2 to 7.7%, chalkiness ranged from 3.4 to 10.6% and drying capacity ranged
from 0.1 to 0.36kg/h. The results obtained shows that drying with
superheated steam can be used to improve rice qualit
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