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971.
Hominy feed is a low value ($83.7/metric ton) coproduct of the corn dry milling process that accounts for nearly 35% of the
starting corn quantity. The average composition of hominy feed on a dry basis is 56.9% starch, 25.2% neutral detergent fiber,
11.1% protein, and 5.3% fat. Starch in hominy feed can be fermented to ethanol thus increasing its levels of protein and fat.
The increase in protein and fat percentages may increase the market competitiveness and price of hominy feed. Hydrolysis and
fermentation were performed on nine hominy feed samples collected from three corn dry milling plants in the USA. The original
hominy feed samples and postfermentation solids were analyzed for starch, protein, fat, and fiber content. Compared to the
original hominy feed, the percentage increase in protein, fat and fiber in postfermentation solids of nine samples ranged
from 10.4 to 21.3, 6.78 to 10.6, and 12.6 to 28.7% (dry basis), respectively. Ethanol yields varied from 271.7 to 380.2 l/metric
ton for the nine hominy feed samples. These results indicate that the value of hominy feed as an animal feedstock can potentially
be increased with fermentation and can produce more profit per metric ton than currently being derived by its sale as a low
protein feed ingredient. 相似文献
972.
We propose a novel normal mode multiple time stepping Langevin dynamics integrator called NML. The aim is to approximate the kinetics or thermodynamics of a biomolecule by a reduced model based on a normal mode decomposition of the dynamical space. Our basis set uses the eigenvectors of a mass reweighted Hessian matrix calculated with a biomolecular force field. This particular choice has the advantage of an ordering according to the eigenvalues, which have a physical meaning of being the square of the mode frequency. Low frequency eigenvalues correspond to more collective motions, whereas the highest frequency eigenvalues are the limiting factor for the stability of the integrator. In NML, the higher frequency modes are overdamped and relaxed near their energy minimum while respecting the subspace of low frequency dynamical modes. Our numerical results confirm that both sampling and rates are conserved for an implicitly solvated alanine dipeptide model, with only 30% of the modes propagated, when compared to the full model. For implicitly solvated systems, NML gives a twofold improvement in efficiency over plain Langevin dynamics for sampling a small 22 atom (alanine dipeptide) model and in excess of an order of magnitude for sampling an 882 atom (bovine pancreatic trypsin inhibitor) model, with good scaling with system size subject to the number of modes propagated. NML has been implemented in the open source software PROTOMOL. 相似文献
973.
Shah SA Rathod IS Suhagia BN Pandya SS Parmar VK 《Journal of chromatographic science》2008,46(8):735-738
A simple, rapid, and reproducible reverse-phase high-performance liquid chromatographic method is developed for the estimation of boswellic acids, the active constituents in Boswellia serrata oleo-gum resin. The chromatographic separation is performed using a mobile phase consisting of acetonitrile-water (90:10, % v/v) adjusted to pH 4 with glacial acetic acid on a Kromasil 100 C18 analytical column with flow rate of 2.0 mL/min and detection at 260 nm. The elution times are 4.30 and 7.11 min for 11-keto beta-boswellic acid (11-KBA) and 3-acetyl 11-keto beta-boswellic acid (A-11-KBA), respectively. The calibration curve is linear in the 11.66-58.30 microg/mL and 6.50-32.50 microg/mL range for 11-KBA and A-11-KBA, respectively. The limits of detection are 2.33 microg/mL and 1.30 microg/mL for 11-KBA and A-11-KBA, respectively. The mean recoveries are 98.24% to 104.17% and 94.12% to 105.92% for 11-KBA and A-11-KBA, respectively. The inter- and intra-day variation coefficients are less than 5%. The present method is successfully applied for the estimation of boswellic acids from the market formulations containing Boswellia serrata extract. 相似文献
974.
Sugars play a critical role in regulating overall cellular metabolism in high altitude growing plants. These plants are shown to have high levels of sugars to enhance their tolerance to abiotic stresses such as drought and freezing temperature. In the present study, a simple, sensitive, selective and reliable HPLC method based on ultrasonic extraction and evaporative light scattering detection (ELSD) has been developed and validated for the simultaneous determination of important sugars (xylose, xylitol, mannitol, glucose and sucrose) and picrosides (picroside-I and picroside-II) in two species Picrorhiza kurroa and P. scrophulariiflora. The analysis was carried out on a Zorbax amino column (250 mm x 4.6 mm i.d., 5 microm) with isocratic elution of acetonitrile:water (78:22, v/v). The method was validated for accuracy, precision, limit of detection and quantification according to International Conference on Harmonization (ICH) guidelines. The drift tube temperature of the ELSD system was set to 81 degrees C and nitrogen flow rate was 2.0 standard liter per minute (SLM). The regression equation revealed a good linear relationship (r(2)=0.9997+/-0.0012) within test ranges. The limit of detection and quantification for seven analytes in ELSD were less than 0.98 and 2.95 microg, respectively. The method showed good reproducibility for the quantification of seven analytes in Picrorhiza species with intra- and inter-day variation of less than 2.0%. 相似文献
975.
Vijay Luxami 《Tetrahedron letters》2008,49(27):4265-4268
Chemosensors 5-7 possessing a quaternary ammonium cation (for electrostatic interactions) and an N-H group(s) (for H-bonding) as recognition sites and an anthracene-9,10-dione as both a chromogenic and fluorescent moiety exhibit absorption and emission changes with fluoride ions only. No significant response to other anions such as Cl−, Br−, I−, , CH3COO−, , and is observed. The dual emission at λmax 580 nm (free 5/6) and λmax 510 and 540 nm (5/6 + F−) in chemosensors 5 and 6 enables ratiometric analysis of fluoride ions. 相似文献
976.
Tryptophan (TRP) is an essential amino acid catabolized mainly through the kynurenine pathway, and part of it is catabolized in the brain. The abnormal depletion of TRP and production of kynurenine (KYN) by two enzymes, tryptophan 2,3-dioxygenase (TDO) and indoleamine 2,3-dioxygenase (IDO), have been linked to various neurological diseases. The ratio of TRP/KYN in plasma is a valuable measure for IDO/TDO activity and the prognosis of disease conditions. The 4-vinylphenylboronic acid (4-VPBA) was evaluated as a novel stationary phase for OT–CEC–MS/MS. TRP, KYN, and 3-hydroxykynurenine were separated using optimum conditions of 15 mM (NH4)2CO3 at pH 8 as a background electrolyte and 25 kV separation voltage on a 90 cm column. The usefulness of the 4-VPBA column for simple, fast, repeatable, and sensitive CEC–ESI–MS/MS application was demonstrated for the quantitation of TRP and KYN in the plasma of healthy human subjects and neuroinflammation subjects. The plasma sample was extracted on a zirconia-based ion-exchange cartridge for simultaneous protein precipitation and phospholipid removal. The method of standard addition, in combination with the internal standards approach, was used to prepare the calibration curve to overcome matrix matching and eliminate procedural errors. The developed quantitation method was validated according to FDA guidelines for sensitivity, accuracy, precision, and extraction recovery. The measured plasma level of TRP and KYN in healthy humans is aligned with the human metabolome database for the same two metabolites. 相似文献
977.
Prasad G. Mahajan Nilam C. Dige Sonali B. Suryawanshi Dattatray K. Dalavi Avinash A. Kamble Dhanaji P. Bhopate Abhijit N. Kadam Vijay V. Kondalkar Govind B. Kolekar Shivajirao R. Patil 《Journal of fluorescence》2018,28(1):207-215
The aqueous suspension of fluorescent nanoparticles were prepared by using 9-anthradehdye derivative (AH). The nanoparticles (AHNPs) were characterized using DLS-zeta sizer and SEM techniques. The photo physical properties of nanoparticles and precursor were measured and compared using UV-absorption spectroscopy, fluorescence spectroscopy and fluorescence lifetime studies. The significant overlap between fluorescence spectrum of AHNPs and excitation spectrum of Riboflavin (RF) led us to explore Fluorescence Resonance Energy Transfer (FRET) studies between AHNPs and RF in aqueous medium. The mechanism of FRET from AHNPs to RF discussed on spectral observations, thermodynamic parameters and changes produces in fluorescence lifetime in absence and presence of different concentrations of RF to AHNPs. The limit of detection for RF (0.071 µM) is considerably low compared with reported methods. Thus, we explore AHNPs as novel nano probe for quantitative determination of RF in pharmaceutical samples based on FRET study. In addition with this, AHNPs has excellent antibacterial activity than the bulk material for two different bacteria culture viz. E. coli and Bacillus sps. 相似文献
978.
The Coulomb blockade (CB) in quantum dots (QDs) is by now well documented. It has been used to guide the fabrication of single
electron transistors. Even the most sophisticated techniques for synthesizing QDs (e.g. MOCVD/MBE) result in an assembly in
which a certain amount of disorder is inevitable. On the other hand, theoretical approaches to CB limit themselves to an analysis
of a single QD. In the present work we consider two types of disorders: (i) size disorder; e.g. QDs have a distribution of
sizes which could be unimodal or bimodal in nature. (ii) Potential disorder with the confining potential assuming a variety
of shapes depending on growth condition and external fields. We assume a Gaussian distribution in disorder in both size and
potential and employ a simplified mean field theory. To do this we rely on the scaling laws for the CB (also termed as Hubbard
U) obtained for an isolated QD [1]. We analyze the distribution in the Hubbard U as a consequence of disorder and observe that Coulomb blockade is partially suppressed by the disorder. Further, the distribution
in U is a skewed Gaussian with enhanced broadening.
相似文献
979.
Blue-emitting europium-ion-doped MgSrAl10O17 phosphor, prepared using the combustion method, is described. An efficient phosphor can be prepared by this method in a muffle furnace maintained at 500 °C in a very short time of few minutes. The phosphor is characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy and BET surface area measurements. Photoluminescence (PL) spectra revealed that europium ions were present in divalent oxidation state. The thermoluminescence (TL) glow curve shows two peaks at around 178 and at 354 °C. The defect centres formed in the phosphor are studied using electron spin resonance (ESR). The ESR spectrum indicates the presence of Fe3+ ions in the non-irradiated system. Irradiated MgSrAl10O17:Eu exhibits lines due to radiation-sensitive Fe3+ ion and a defect centre. The centre is characterized by an isotropic g-value of 2.0012 and is assigned to a F+ centre. The radiation-sensitive Fe3+ ion appears to correlate with the main TL peak at 178 °C. During irradiation an electron is released from Fe2+ and is trapped at an anion vacancy to form F+ centre. During heating, an electron is liberated from the defect centre and recombines with Fe3+ emitting light. 相似文献
980.
Vishal Sharma Raj Kumar Karan Devgan Pawan Kumar Mishra Adam Ekielski Vijay Kumar 《光谱学快报》2018,51(5):205-215
The multivariate analysis methods have recently gained high popularity within the field of forensic sciences because of their high accuracy and precision. The accurate and unbiased results are the preliminary need for a forensic investigation. The aim of the present work is to examine the marker pen inks which are widely used in various places like documentation in parcels, for photograph attestation, and also as a study material in the classroom. This research is focused on the three important aspects; first is to characterize the marker inks, second, to discriminate permanent marker and whiteboard marker inks using destructive (extracting of ink samples from paper substrate) and nondestructive (without ink extraction) techniques of ultraviolet–visible absorbance combined with peak identification examination as well as chemometric methods, and the third is to build a classification model for permanent and whiteboard marker inks. It is concluded that the chemometric method, that is, principal component analysis provides better discrimination power as compared to visual examination. However, destructive and nondestructive approaches give almost similar discriminating power. The classification model developed using linear discriminant analysis provides 87.5% of correct classification of marker ink samples. The method can further be used to formulate a statistical model for the determination of class/group of the other forensic exhibits. 相似文献