A modified sludge process reduction activated sludge (SPRAS) technology was developed by inserting a sludge process reduction (SPR) module, composed of an aeration tank and a settler, before the activated sludge system was proposed in this study. Compared with the anaerobic/anoxic/aerobic (AAO) process, the SPRAS resulted in a remarkable decrease in sludge production by 76.6%; sludge decay owing to lengthy solids retention time (about 121.5 d) could be the major cause. During the 217-day operation, the oxidation-reduction potential (ORP) (from 54 to -198 mV) and pH (from 7.8 to 5.0) at the bottom of the SPR settler gradually decreased, and low ORP and pH were in favor of sludge reduction in the SPRAS system. The insertion of the SPR module improved the removal efficiencies of suspended solids, chemical oxygen demand and ammonium nitrogen, and total nitrogen concentration in the effluent was reduced from 23.89 ± 4.82 to 14.16 ± 3.98 mg/L by 50% influent bypassing the SPR module. These results indicated that the SPRAS process could produce much less excess sludge and guarantee better effluent quality than the AAO process.
The study was conducted in order to analyze the incidence of heparin-induced thrombocytopenia (HIT) and heparin-induced thrombocytopenia and thrombosis syndrome (HITTS) in 240 patients from the Department of Vascular Surgery in China, to evaluate the current laboratory detection technique, and to explore the feasibility for the technique to be developed in China.
The objective of the present study was to develop a new method for the simultaneous quantitation of imperatorin and its metabolite xanthotoxol in rat plasma. The samples were prepared with hollow fiber liquid phase microextraction (HF-LPME). The optimized extraction procedure was acquired by assessing extraction solvent, length of the fiber, agitation rate, extraction temperature and time. A comparison of sample pretreatment ways between HF-LPME and deproteinization with methanol was performed, which demonstrated less ion suppression and better sensitivity of HF-LPME. Analytes were separated on a C18 column with a gradient elution consisted of methanol and water containing 1mmol/L ammonium acetate. The detection was accomplished by electrospray ionization (ESI) source operating in the positive ionization mode. Selected-multiple-reaction monitoring (SMRM) scanning was employed, which guaranteed a higher sensitivity compared with MRM mode. Calibration curves were linear over investigated ranges with correlation coefficients greater than 0.9979. Precision varied from 0.26% to 14%, and the accuracy varied within ±5.5%. The developed method was successfully applied to the pharmacokinetic research of imperatorin and its metabolite xanthotoxol after oral administration of imperatorin to rats.
A sensitive and selective liquid chromatography and tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous determination of four flavonoids (schaftoside, isovitexin, luteolin, and apigenin) and one phenolic acid (ferulic acid) in rat plasma using sulfamethoxazole as the internal standard (IS). The separation was performed using a Diamonsil C18 column, which was eluted with methanol (A) and 0.1‰ acetic acid (B). The gradient condition was as follows: 0-5min, 40-60% A; 5-6min, 60-95% A; and 6-10min, maintained at 95% A. The analytes were detected using a hybrid quadrupole linear ion trap mass spectrometer that was equipped with an electrospray ionization source in the negative ion and multiple-reaction monitoring modes. A full validation of the method was performed. The linearity of the analytical response was good, with correlation coefficients greater than 0.9925 for all of the compounds within the concentration range. The lower limits of quantitation (LLOQ) of schaftoside, isovitexin, luteolin, apigenin, and ferulic acid in rat plasma were 1.66, 0.84, 3.69, 1.70, and 3.91ng/mL, respectively. The intra-day and inter-day precisions of the investigated components exhibited an RSD within 13.20%, and the accuracy (RE%) ranged from -8.47% to 10.90%. The results indicated that the developed method is sufficiently reliable for the pharmacokinetic study of schaftoside, isovitexin, apigenin, luteolin, and ferulic acid in rats following oral administration of the Herba Desmodii Styracifolii extract.
Gossypium mustelinum ((AD)4 ) is one of five disomic species in Gossypium. Three 45S ribosomal DNA (rDNA) loci were detected in (AD)4 with 45S rDNA as probe, and three pairs of brighter signals were detected with genomic DNA (gDNA) of Gossypium D genome species as probes. The size and the location of these brighter signals were the same as those detected with 45S rDNA as probe, and were named GISH-NOR. One of them was super-major, which accounted for the fact that about one-half of its chromosome at metaphase was located at chromosome 3, and other two were minor and located at chromosomes 5 and 9, respectively. All GISH-NORs were located in A sub-genome chromosomes, separate from the other four allopolyploid cotton species. GISH-NOR were detected with D genome species as probe, but not A. The greatly abnormal sizes and sites of (AD)4 NORs or GISH-NORs indicate a possible mechanism for 45S rDNA diversification following (AD)4 speciation. Comparisons of GISH intensities and GISH-NOR production with gDNA probes between A and D genomes show that the better relationship of (AD)4 is with A genome. The shortest two chromosomes of A sub-genome of G. mustelinum were shorter than the longest chromosome of D sub-genome chromosomes. Therefore, the longest 13 chromosomes of tetraploid cotton being classified as A sub-genome, while the shorter 13 chromosomes being classified as D sub-genome in traditional cytogenetic and karyotype analyses may not be entirely correct.
Noble metal/semiconductor nanocomposites play an important role in high efficient photocatalysis. Herein, we demonstrate a facile strategy for fabrication of hollow Pt-ZnO nanocomposite microspheres with hierarchical structure under mild solvothermal conditions using Zn (CH(3)COO)(2)·2H(2)O and HPtCl(4) as the precursors, and polyethylene glycol-6000 (PEG-6000) and ethylene glycol as the reducing agent and solvent, respectively. The as-synthesized ZnO and Pt-ZnO composite nanocrystals were well characterized by powder X-ray diffraction (XRD), nitrogen-physical adsorption, scanning electron microscopy (SEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectra (DRS), and photoluminescence (PL) emission spectroscopy. It was found that Pt content greatly influences the morphology of Pt-ZnO composite nanocrystals. Suitable concentration of HPtCl(4) in the reaction solution system can produce well hierarchically hollow Pt-ZnO nanocomposite microspheres, which are composed of an assembly of fine Pt-ZnO nanocrystals. Photocatalytic tests of the Pt-ZnO microspheres for the degradation of the dye acid orange II revealed extremely high photocatalytic activity and stability compared with those of pure ZnO and corresponding Pt deposited ZnO. The remarkable photocatalytic performance of hollow Pt-ZnO microspheres mainly originated from their unique nanostructures and the low recombination rate of the e(-)/h(+) pairs by the platinum nanoparticles embedded in ZnO nanocrystals.
We investigated the locations of 5S and 45S rDNA in Gossypium diploid A, B, D, E, F, G genomes and tetraploid genome (AD) using multi-probe fluorescent in situ hybridization (FISH) for evolution analysis in Gossypium genus. The rDNA numbers and sizes, and synteny relationships between 5S and 45S were revealed using 5S and 45S as double-probe for all species, and the rDNA-bearing chromosomes were identified for A, D and AD genomes with one more probe that is single-chromosome-specific BAC clone from G. hirsutum (A1D1). Two to four 45S and one 5S loci were found in diploid-species except two 5S loci in G. incanum (E4), the same as that in tetraploid species. The 45S on the 7th and 9th chromosomes and the 5S on the 9th chromosomes seemed to be conserved in A, D and AD genomes. In the species of B, E, F and G genomes, the rDNA numbers, sizes, and synteny relationships were first reported in this paper. The rDNA pattern agrees with previously reported phylogenetic history with some disagreements. Combined with the whole-genome sequencing data from G. raimondii (D5) and the conserved cotton karyotype, it is suggested that the expansion, decrease and transposition of rDNA other than chromosome rearrangements might occur during the Gossypium evolution.
The experiment on individual chromosome assignments and chromosomal diversity was conducted using a multi-probe fluorescence in situ hybridization (FISH) system in D subgenome of tetraploid Gossypium barbadense (D(b)), G. thurberi (D(1)) and G. trilobum (D(8)), which the later two were the possible subgenome donors of tetraploid cottons. The FISH probes contained a set of bacterial artificial chromosome (BAC) clones specific to 13 individual chromosomes from D subgenome of G. hirsutum (D(h)), a D genome centromere-specific BAC clone 150D24, 45S and 5S ribosomal DNA (rDNA) clones, respectively. All tested chromosome orientations were confirmed by the centromere-specific BAC probe. In D(1) and D(8), four 45S rDNA loci were found assigning at the end of the short arm of chromosomes 03, 07, 09 and 11, while one 5S rDNA locus was successfully marked at pericentromeric region of the short arm of chromosome 09. In D(b), three 45S rDNA loci and two 5S rDNA loci were found out. Among them, two 45S rDNA loci were located at the terminal of the short arm of chromosomes D(b)07 and D(b)09, whilst one 5S rDNA locus was found situating near centromeric region of the short arm of chromosome D(b)09. The positions of the BAC clones specific to the 13 individual chromosomes from D(h) were compared between D(1), D(8) and D(b). The result showed the existence of chromosomal collinearity within D(1) and D(8), and as well between them and D(b). The results will serve as a base for understanding chromosome structure of cotton and polyploidy evolution of cotton genome and will provide bio-information for assembling the sequences of finished and the on-going cotton whole genome sequencing projects.
Degradation of perfluorooctanoic acid (PFOA) is of great importance due to its global distribution, persistence and toxicity to bioorganisms. In present study, a composite TiO(2) with multiple wall carbon nanotubes (MWCNTs) was synthesized using sol-gel method and it was used as photocatalyst to degrade PFOA in water. The prepared composite catalyst displayed significant absorption in UV to visible light region. The loading content of TiO(2) on MWCNTs could be adjusted by changing the ratio of precursor to MWCNTs. Due to the combined effect of the adsorption ability and e(-) transport capacity of MWCNT, the composites displayed much higher photocatalytic ability to PFOA as compared to pure TiO(2) under UV irradiation. The photocatalyst prepared with 10:1 of tetrabutyl titanate/MWCNT was the most effective. With the optimal dosage at 1.6 g L(-1), almost 100% of PFOA was degraded in acid medium after irradiation for 8h. It was proposed that PFOA were mainly degraded by stepwise losing a moiety of CF(2).
Bi(2)WO(6) displayed great photolytic degradation efficiency to bisphenol A (BPA) under simulated solar light irradiation but its reaction mechanism and the impacts of coexisting substances on the degradation remain unclear. In present study, the reaction mechanism was investigated using DMPO spin-trapping ESR spectra and experiments with scavengers of hydroxyl radicals (*OH) and holes. The results supported that hole oxidation mainly governed the photodegradation process. As a common humic substance in natural water, humic acid accelerated the degradation of BPA when its concentration was 1mg/L, while the photodegradation was impeded with the increase of humic acid concentration in the range of 5-20mg/L. Almost all anions, including NO(3)(-), HCO(3)(-), Cl(-), SO(4)(2-) inhibited the degradation of BPA by Bi(2)WO(6) and their inhibition effects followed the order of SO(4)(2-)>Cl(-)>HCO(3)(-)>NO(3)(-). Cations of Na(+), K(+), Ca(2+) and Mg(2+) displayed slight suppressing effect on BPA degradation mainly due to the impact of Cl(-) coexisting in the solution. However, Cu(2+) hindered the BPA photodegradation heavily. Fe(3+) and H(2)O(2) affected the photodegradation in a complicated way: they suppressed or promoted the photodegradation depending on their concentrations. This could be the result of competition between photolyitc hole generated by Bi(2)WO(6) and OH produced by Fe(3+) or H(2)O(2.).
Bismuth tungstate (Bi2WO6) catalysts of different morphology were synthesized with a hydrothermal method by controlling the pH of the reaction solution. The properties of the synthesized catalysts were characterized and all catalysts presented high photoabsorption capacity in the range of UV light to visible light around 450 nm. The surface area of the catalysts decreased but the crystallinity increased with the pH of the hydrothermal reaction solution in the range of 4-11. It was found that the crystallinity of the catalysts played an important role on their degradation capacity to Bisphenol A (BPA). Bi2WO6 catalyst prepared at pH 11 displayed a mesoporous structure and it showed the highest photocatalytic activity to degrade BPA under simulated solar light irradiation. Nearly 100% of BPA with original concentration at 20 ppm was removed after 30 min irradiation in a solution with pH 10 and Bi2WO6 amount of 1.0 g L(-1). Furthermore, 86.6 and 99.1% of the total organic carbon was eliminated after 60 and 120 min irradiation, respectively. Only one intermediate at m/z 133 was observed by LC/MS and a simple pathway of BPA degradation by Bi2WO6 was proposed.
A high-performance liquid chromatography coupled with photo diode array detection method is developed for simultaneous determination of seven active components in Qibaomeiran pill, including rutin, 2,3,5,4-tetrahydroxystilbene-2-O-beta-D-glycoside, ferulic acid, psoralen, isopsoralen, emodin, and physcion. The analysis is performed on a C(18) column using a mobile phase composed of A (0.1% acetic acid) and B (acetonitrile) with linear gradient elution. Four wavelengths at 245, 290, 320, and 350 nm were chosen as the monitoring wavelength to determine seven active components, respectively. All the compounds show good linearity (r > 0.999). The developed method is fully validated in respect to precision, repeatability, and accuracy. The proposed method is successfully applied to quantify the seven active components in different Qibaomeiran pill samples. The results indicate that the developed assay could be considered as a suitable quality control method for the Qibaomeiran pill.
Rapid, sensitive, and selective high-performance liquid chromatography methods were developed and validated for determination of m-nisoldipine enantiomers in rat tissues. All of the samples were prepared based on a simple and efficient liquid-liquid extraction method. After validating that no racemation occurred by ULTRON ES-OVM (Japan), m-nisoldipine enantiomers were determined, respectively, on a reverse-phase C(18) column (5 microm, 250 x 4.6 mm). This method was applied to study tissue distribution of m-nisoldipine enantiomers in rats after a single administration of m-nisoldipine enantiomers. By the two-sample t test, there were basically no significant differences between the two enantiomers in each tissue ( p > .05), which indicates that they may have the same potency in rats. In small intestine, lung, liver, and spleen, the concentrations of R-(-)- and S-(+)-m-nisoldipine were high at 30 and 150 min than that at 90 min, which showed that m-nisoldipine enantiomers may have the phenomenon of hepatoenteral circulation. A small quantity of the prototype of R-(-)- and S-(+)-m-nisoldipine in brain showed that they can cross the blood-brain barrier to arrive at the brain tissue. The high quantity of distribution in lung and brain implied that the lipophilicity of the drug was powerful.
A sensitive liquid chromatography and tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous analysis of 15 flavonoids and 3 phenolic acids in Herba Lysimachiae and Herba Desmodii Styracifolii. Separation was performed using a Diamonsil C(18) column, which was eluted with methanol (A) and 0.1‰ acetic acid (B). The gradient condition was as follows: 0-34 min, 20-34% A; 34-38 min, 34-95% A; maintained 95% A for the next 4 min. Analytes were detected using a hybrid quadrupole linear ion trap mass spectrometer that was equipped with an electrospray ionisation source in the negative ion and multiple-reaction monitoring modes. A full validation of the method was performed, including the linearity, precision, and accuracy, as well as limits of detection and quantification. The results indicated that the developed method was simple, sensitive and reliable. Furthermore, the method was successfully applied to differentiate 16 batches of Herba Lysimachiae and 21 batches of Herba Desmodii Styracifolii.
The study was conducted on the individual chromosome identification in Gossypium darwinii (A(d)D(d)), G. klotzschianum (D(3k)), G. davidsonii (D(3d)), G. armourianum (D(2-1)) and G. aridum (D(4)) using a multi-probe fluorescence of in situ hybridization (FISH) system. Comparative analysis on their genetic maps with that of physical maps was made as well. The FISH probes used contained two sets of bacterial artificial chromosome (BAC) clones [one is specific to 26 individual chromosomes from A and D subgenomes of G. hirsutum (A(h) and D(h)) while the other is a D genome centromere-specific BAC clone 150D24], 45S and 5S rDNA clones. The results showed that all A(d) chromosomes were marked with the 13 A(h) chromosome-specific BAC clones, whilst all D(d), D(3k), D(3d), D(2-1) and D(4) chromosomes and chromosomal arms were identified with the 13 D(h) chromosome-specific BAC clones and the D genome centromere-specific BAC. According to the homology within D subgenomes which are between A (D) genome and A (D) subgenome, the systematic nomenclature for individual chromosome in the five species was established. The chromosomes of A (D) subgenomes in G. darwinii were named as A(d)01-A(d)13 (D(d)01-D(d)13). The chromosomes in D(3k), D(3d), D(2-1) and D(4) were named as D(3k)01-D(3k)13, D(3d)01-D(3d)13, D(2-1)01-D(2-1)13 and D(4)01-D(4)13, respectively. Based on the successful identification for individual chromosomes, 45S and 5S rDNA were located to the special chromosomes and chromosomal arms for all five species. And there appeared chromosomal collinearity from the BAC clones among different species by comparing BACs positions, which suggested that the majority of chromosome segment homology may exist between D genomes and D subgenome. Moreover, as the genetic map and physical map were integrated, the orientations of genetic maps for D(d) and D genomes of diploid cotton were established. The orientations of some of chromosomes in genetic maps (D(d)03, D(d)04, D(d)06, D(d)09, D(d)10 and D(d)12) were found switched. The SSR marker in the middle of linkage group 04 was corrected at nearby the end of chromosome 04 by FISH. The study will be helpful to establish a theoretical basis using the wild gene bank to exploit more genes aiming for cotton breeding and will provide powerful evidences both for the evolution of Gossypium and assembling the sequences of the obtained and as well the on-going whole genome sequencing projects of cotton.
Fluorescence in situ hybridization (FISH) has become one of the most important techniques applied in plant molecular cytogenetics. However, the application of this technique in cotton has lagged behind because of difficulties in chromosome preparation. The focus of this article was FISH performed not only on cotton pachytene chromosomes, but also on cotton extended DNA fibers. The cotton pollen mother cells (PMCs) instead of buds or anthers were directly digested in enzyme to completely breakdown the cell wall. Before the routine acetic acid treatment, PMCs were incubated in acetic acid and enzyme mixture to remove the cytoplasm and clear the background. The method of ice-cold Carnoys solution spreading chromosome was adopted instead of nitrogen removed method to avoid chromosomes losing and fully stretch chromosome. With the above-improved steps, the high-quality well-differentiated pachytene chromosomes with clear background were obtained. FISH results demonstrated that a mature protocol of cotton pachytene chromosomes preparation was presented. Intact and no debris cotton nuclei were obtained by chopping from etiolation cotyledons instead of the conventional liquid nitrogen grinding method. After incubating the nuclei with nucleus lysis buffer on slide, the parallel and clear background DNA fibers were acquired along the slide. This method overcomes the twist, accumulation and fracture of DNA fibers compared with other methods. The entire process of DNA fibers preparation requires only 30 min, in contrast, it takes 3 h with routine nitrogen grinding method. The poisonous mercaptoethanol in nucleus lysis buffer is replaced by nonpoisonous dithiothreitol. PVP40 in nucleus isolation buffer is used to prevent oxidation. The probability of success in isolating nuclei for DNA fiber preparation is almost 100% tested with this method in cotton. So a rapid, safe, and efficient method for the preparation of cotton extended DNA fibers suitable for FISH was established.
Microcystin-RR (MC-RR) is one of the most common cyanotoxin microcystins in fresh water and is of great concern due to its potential hepatotoxicity. In the present study, Bi(2)WO(6) was synthesized with a hydrothermal method by varying the pH of the reaction solution in the range of 1-11. The surface area of the catalysts decreased, but the crystallinity and crystal size increased with the pH. The adsorption and degradation capacities of the catalysts decreased with increasing the preparation solution pH. The Bi(2)WO(6) prepared at pH 1 (Bi(2)WO(6)-pH1) displayed the highest adsorption and degradation capacity to MC-RR even though it consisted of randomly aggregated particles. Nearly 100% of MC-RR at 10 mg L(-1) was removed after 30 min of irradiation of near-ultraviolet light (300-400 nm) in a solution with Bi(2)WO(6) concentration of 0.2 g L(-1). The photodegradation efficiency of Bi(2)WO(6)-pH1 was greater in acid medium than in basic solutions. Several intermediate products were observed and identified by liquid chromatography/mass spectrometry/mass spectrometry, and a unique photodegradation pathway was proposed. It was assumed that a photo-Kolbe process happened at the site carboxyl acid group of the d-Glu residue by the photogenerated holes, producing a hydroperoxyl product at m/z 513.8. This intermediate could be further decomposed to an alcohol product at m/z 505.8 and a ketone product at m/z 504.8. The aromatic ring and diene bond of the Adda chain could also be attacked by the holes and form phenol and diol products.
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