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1.
Timoth Mkilima Davud Devrishov Kydyrbekova Assel Nurbala Ubaidulayeva Almas Tleukulov Alissa Khassenova Nargiza Yussupova Dinara Birimzhanova 《Molecules (Basel, Switzerland)》2022,27(22)
Groundwater is one of the main sources of water for irrigation used worldwide. However, the application of the resource is threatened by the possibility of high saline levels, especially in low-lying coastal regions. Furthermore, the lack of readily accessible materials for successful treatment procedures makes the purification of such water a constant challenge. Based on the fact that natural zeolite is one of the easily accessible and relatively cheap filter materials, this study examined the potential use of high-salinity groundwater filtered by natural zeolite for irrigation. Zeolite-filled filters at two different depths (0.5 m and 1 m) were studied. The samples were collected from the low-lying areas of Dar es Salaam City, Tanzania. The study observed that when the raw groundwater samples were exposed to the 0.5 m column depth, sodium (Na+) had the lowest removal efficiency at 40.2% and calcium (Ca2+) had the highest removal efficiency at 98.9%. On the other hand, magnesium (Mg2+) had the lowest removal efficiency, at about 61.2%, whereas potassium (K+) had up to about 99.7% removal efficiency from the 1 m column depth treatment system. Additionally, from the salinity hazard potential analysis, most of the samples fell within C4 (based on the electrical conductivity), which is a “very high salinity” class, and based on the quality it means the water cannot be directly applied for irrigation purposes. From the 0.5 m column depth, most of the samples fell within C3 (the “high salinity” class), and from the 1 m column depth most of the samples fell within C1 (“low salinity” class). The findings of this study offer some valuable insight into the prospective use of natural zeolite for the filtration of saline groundwater before its application for irrigation. 相似文献
2.
Titanium-mediated cross-coupling of allenic alcohols with alkynes has been investigated. Divergent reaction pathways were discovered that provide either stereodefined 1,4-dienes or substituted cross-conjugated trienes. In short, allene substitution plays a critical role in the determination of reaction pathway. 相似文献
3.
Linda M. Guiney Alissa D. Agnello Julia C. Thomas Koko Takatori Nolan T. Flynn 《Colloid and polymer science》2009,287(5):601-608
We report the synthesis of N-isopropylacrylamide-based hydrogels containing either an anionic (acrylic acid) or cationic ([2-(acryloyloxy)ethyl]trimethylammonium
chloride) co-monomer. These hydrogels were cross-linked with a cleaveable (N,N′-cystaminebisacrylamide) and/or inert (N,N′-methylenebisacrylamide) molecule in four combinations. Gold nanostructures were then synthesized within these hydrogel matrices
by in situ reduction of a metal ion precursor. The resulting eight nanocomposites and their non-gold-containing (native) analogs
were characterized with several analytical methods. UV–visible and infrared spectroscopy revealed differences among the samples
based largely on the concentration and identity of cross-linking agent. Equilibrium swelling masses and phase transition behavior
point to differences among samples on charge of the hydrogel backbone, cross-linker type, and presence or absence of gold
nanostructures. A molecular level explanation for these observations is described. 相似文献
4.
The nonideal adsorbed solution (NAS) theory has been formally extended to adsorption at the air/water interface from aqueous mixtures of ionic surfactants, explicitly accounting for the surface potential of the adsorbed monolayer with the Gouy-Chapman theory. This new ionic NAS (iNAS) theory is thermodynamically consistent and, when coupled to a micellization model, is valid for concentrations below and above the mixed cmc. Counterion binding is incorporated into the model using two fractional binding parameters, beta(sigma) for the adsorbed monolayer and beta(m) for the micelles. The regular solution theory is used to model the nonideal interactions within the adsorbed monolayer and within the mixed micelles. New tension data for an equimolar mixture of sodium dodecyl sulfate (SDS) and sodium dodecyl sulfonate (SDSn) at two salinities fit this model well when mixing is ideal. The total surface densities, the surface compositions, and the surface potentials for the mixed monolayers are calculated. When there is no added salt, at total surfactant concentrations below the mixed cmc, the adsorbed monolayer is enriched in SDSn, but at total concentrations at and above the mixed cmc, the adsorbed monolayer is nearly an equimolar mixture. In the presence of 100 mM NaCl, the adsorbed monolayer is nearly an equimolar mixture, independent of the total surfactant concentration. 相似文献
5.
The human frontal lobe is critical for cognitive function in the healthy brain. Many psychiatric disorders including schizophrenia and bipolar disorder are associated with apparent mitochondrial dysfunction and bioenergetic abnormalities in the frontal lobe. Therefore, measuring cerebral bioenergetics associated with creatine kinase and adenosine triphosphate (ATP) synthase reactions could provide crucial information regarding the underlying molecular mechanisms associated with psychiatric disorders. In this study, the unidirectional forward chemical exchange metabolic fluxes of creatine kinase and ATP synthase reactions as well as reverse chemical exchange metabolic flux associated with ATP hydrolysis were determined at 4T by 31P magnetization transfer. The current experiments indicate that the kinetic network of PCr↔ATP↔Pi can be measured reliably in the human frontal lobe at 4T, which will enable detailed in vivo characterization of bioenergetic abnormalities in a variety of neuropsychiatric disorders. 相似文献
6.
Bing Gong Erik Hoyt Heather Lynaugh Irina Burnina Renee Moore Alissa Thompson Huijuan Li 《Analytical and bioanalytical chemistry》2013,405(17):5825-5831
N-Linked glycosylation is a major protein modification involved in many essential cellular functions. Methods capable of quantitative glycan analysis are highly valuable and have been actively pursued. Here we describe a novel N-glycosylamine-based strategy for isotopic labeling of N-linked glycans for quantitative analysis by use of mass spectrometry (MS). This strategy relies on the primary amine group on the reducing end of freshly released N-linked glycans for labeling, and eliminates the need for the harsh labeling reaction conditions and/or tedious cleanup procedures required by existing methods. By using NHS-ester amine chemistry we used this strategy to label N-linked glycans from a monoclonal antibody with commercially available tandem mass tags (TMT). Only duplex experiments can be performed with currently available TMT reagents, because quantification is based on the intensity of intact labeled glycans. Under mild reaction conditions, greater than 95 % derivatization was achieved in 30 min and the labeled glycans, when kept at ?20 °C, were stable for more than 10 days. By performing glycan release, TMT labeling, and LC–MS analysis continuously in a single volatile aqueous buffer without cleanup steps, we were able to complete the entire analysis in less than 2 h. Quantification was highly accurate and the dynamic range was large. Compared with previously established methods, N-glycosylamine-mediated labeling has the advantages of experimental simplicity, efficient labeling, and preserving glycan integrity.
Principle of N-Glycosylamine-mediated isotope labeling for mass spectrometry-based quantitative analysis of N-linked glycans 相似文献
7.
Yang X Zhang AY Wheeler DA Bond TC Gu C Li Y 《Analytical and bioanalytical chemistry》2012,402(2):687-691
This paper reports the first step toward the development of a glucose biosensor based on Raman spectroscopy and a photonic
crystal fiber (PCF) probe. Historically, it has been very challenging to detect glucose directly by Raman spectroscopy due
to its inherently small Raman scattering cross-section. In this work, we report the first quantitative glucose Raman detection
in the physiological concentration range (0–25 mM) with a low laser power (2 mW), a short integration time (30 s), and an
extremely small sampling volume (∼50 nL) using the highly sensitive liquid-filled PCF probe. As a proof of concept, we also
demonstrate the molecular specificity of this technique in the presence of a competing sugar, such as fructose. High sensitivity,
flexibility, reproducibility, low cost, small sampling volume, and in situ remote sensing capability make PCF a very powerful
platform for potential glucose detection based on Raman spectroscopy. 相似文献
8.
Shakya Anshul Chikhale Rupesh V. Bhat Hans Raj Alasmary Fatmah Ali Almutairi Tahani Mazyad Ghosh Surajit Kumar Alhajri Hassna Mohammed Alissa Siham A. Nagar Shuchi Islam Md Ataul 《Molecular diversity》2022,26(1):265-278
Molecular Diversity - Transmembrane protease serine-2 (TMPRSS2) is a cell-surface protein expressed by epithelial cells of specific tissues including those in the aerodigestive tract. It helps the... 相似文献
9.
Prosser AJ Retter U Lunkenheimer K 《Langmuir : the ACS journal of surfaces and colloids》2004,20(7):2720-2725
The dynamic surface tension data for n-dodecanoic acid in 0.005 M hydrochloric acid, for as-received as well as for surface-chemically pure solutions, show the presence of a prolonged induction period, clearly indicating that the adsorption of this nonionic surfactant is not simply diffusion-controlled. A kinetic model for the reversible formation of monolayer islands, long known in the field of electrochemistry, is shown to also apply to the adsorption of n-dodecanoic acid at the air/water interface. The rate constant increases linearly with increasing bulk concentration, while the induction time decreases exponentially. The phenomenon of nucleation at the air/water interface is consistent with the direct experimental observation of the formation of solid-like patches as the interfacial region is drastically compressed. 相似文献
10.
Li Y de Silva PG Xi L van Winkle A Lin JJ Ahmed S Geng ML 《Biomedical chromatography : BMC》2008,22(12):1374-1384
Simultaneous extraction, separation and quantitation of reduced nicotinamide adenine dinucleotide (NADH), reduced nicotinamide adenine dinucleotide phosphate (NADPH), flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN) in Chinese Hamster Ovary (CHO) cells were investigated. The separation of flavins and nicotinamide cofactors was performed by capillary electrophoresis with laser-induced fluorescence detection at the excitation wavelength of 325 nm. The separation protocol was established by investigating the excitation wavelength, high voltage and effects of buffer nature, pH and concentration. All endogenous fluorophores riboflavin, FAD, FMN, NADH and NADPH show wide linear range of quantitation. The limits of detection for the five compounds ranged from 4.5 to 23 nM. Extraction conditions were optimized for high-efficiency recovery of all endogenous fluorophores from CHO cells. To account for the complex matrix of cell extracts, a standard addition method was used to quantify FAD, FMN, NADH and NADPH in CHO cells. The quantitative results should be useful to reveal the metabolic status of cells. The protocols for extraction, separation and quantitation are readily adaptable to normal and cancer cell lines for the analysis of endogenous fluorophores. 相似文献