[Objective] This study aimed to analyze the volatile constituents in Lonicera japonica Thunb. from different origins. [Method] HP-5MS capillary columns were used and column temperature was controlled by a program. MS ...[Objective] This study aimed to analyze the volatile constituents in Lonicera japonica Thunb. from different origins. [Method] HP-5MS capillary columns were used and column temperature was controlled by a program. MS analysis was performed with EI and quadruple mass analyzer. The volatile constituents in L. japonica Thunb. were identified by NIST02 and Wiley275 libraries, and their relative contents were determined with chromatographic peak area normalization method. [Result] According to GC-MS total ion-current chromatograms, 35 volatile constituents were identified in L. japonica Thunb. from Guangxi Zhuang Autonomous Region, mainly including methyl linolenate, n-hexadecanoic acid and ζ-muurolene; 18 volatile constituents were identified in L. japonica Thunb. from Hunan Province, mainly including n-hexadecanoic acid, linoleic acid and α-curcumene. [Conclusion] Main volatile constituents in L. japonica Thunb. from two different origins varied significantly.展开更多
[Objective] This study was conducted to explore the internal relationship among root biological traits of sweetpotato, as well as the regularity in their formation and differentiation. [Method] The root traits of 10 s...[Objective] This study was conducted to explore the internal relationship among root biological traits of sweetpotato, as well as the regularity in their formation and differentiation. [Method] The root traits of 10 sweetpotato cultivars were measured through hydroponic culture in a greenhouse and field survey, and then their correlations were analyzed by statistical methods. [Result] The root morphological traits of sweetpotato at seedling stage such as projected area, surface area, average diameter and volume processed the highest contribution rate (80.56%) 10 d after transplanting, and the contribution rate of root average diameter reached 27.79% 20 d after transplanting. Storage root fresh weight per plant shared extremely significant positive correlations with storage root fresh weight of penultimate node and storage root fresh weight of antepenultimate node, and a significant positive corre- lation with commercial storage root number, and a significant negative correlation with storage root number of penultimate node. Among them, the correlation coeffi- cient of storage root fresh weight per plant with storage root fresh weight of antepenultimate node was the highest (0.659 5). Fifteen days after transplanting, storage root fresh weight per plant had significant negative correlations with root projected area, surface area and volume. There was a significant positive correlation between root dry weight and storage root fresh weight per plant 25 d after transplanting. Root dry weight, volume, length, average diameter of sweetpotato seedlings had higher relational degrees with storage root fresh weight per plant. Ten and twenty days after transplanting were important time for the growth and differentiation of sweetpotato roots. In addition, node length and planting depth had certain influence on sweetpotato yield, and direct relationship existed between the seedling root biological traits and storage root yield of sweetpotato. [Conclusion] The results provide theoretical support for standard cultivation and new variety breeding of sweetpotato.展开更多
[Objective] This study aimed to analyze the volatile constituents in bamboo leaves. [Method] The volatile compositions in bamboo leaves were analyzed by headspace-gas chromatography-mass spectrometry (HS-GC/MS), and...[Objective] This study aimed to analyze the volatile constituents in bamboo leaves. [Method] The volatile compositions in bamboo leaves were analyzed by headspace-gas chromatography-mass spectrometry (HS-GC/MS), and identified by searching their mass spectra in NIST database. The relative percentages of them were calculated by the GC peak areas. [Result] Fifty-three chemical constituents in bamboo leaves were separated. Among them, the main components were alcohols, ketones and aldehydes, and these compounds contained unsaturated bonds. [Con- clusion] HS-GC/MS was simple and less sample-demanding and can be used for rapid analysis of volatile constituents in bamboo leaves and provide scientific basis for further research and development of bamboo leaves.展开更多
Nanoparticles of pure and Cu/Ag-doped CdS and ZnS have been synthesized via chemical bath deposition without using any capping or toxic reagents.The synthesis was carried out through a simple and less expensive green ...Nanoparticles of pure and Cu/Ag-doped CdS and ZnS have been synthesized via chemical bath deposition without using any capping or toxic reagents.The synthesis was carried out through a simple and less expensive green method.The XRD result shows that both pure CdS and ZnS and their doped derivatives are of high crystalline with hexagonal packing structure.The average crystalline size of all nanoparticles was calculated using Debye-Scherrer formula.The crystalline size of nanoparticles of pure samples varied with that of the doped sample.The average crystalline sizes of all nanoparticles are found to be in the range of 5.5-2.2 nm for CdS(from pure to doped) and 4.3-3.4 nm for ZnS,respectively.The band gap values obtained from UV-visible spectra are in the range of 3.5-2.1 e V for CdS and 3.3-2.7 e V for ZnS derivatives,respectively.The FTIR spectral data give characteristic peaks for Cd—S,Cu—S,Ag—S and Zn—S bonds and confirm the formation of respective nanoparticles.The peaks corresponding to the microstructural formation are also observed.The FE-SEM images show the granular morphological structure for all the samples.The agglomeration size of the samples in the range of 10-50 nm for CdS:Cu and 50-100 nm for ZnS:Cu is observed.展开更多
A novel second-order nonlinear optical chromophore (DCDHF-2-V) was synthesized from 3-Hydroxy-3-methyl-2-butanae, propanedinitrile and 4-diethylaminobenzaldehyde by aldol condensation reaction. Molecular structural ...A novel second-order nonlinear optical chromophore (DCDHF-2-V) was synthesized from 3-Hydroxy-3-methyl-2-butanae, propanedinitrile and 4-diethylaminobenzaldehyde by aldol condensation reaction. Molecular structural characterization was investigated by elemental analysis, FTIR, and 1H-NMR spectra. The melting point obtained from DSC thermogram was almost 251 ℃, and the compound shows a thermal stability up to 270 ℃. Second-order NLO properties of the chromophore were measured by solvatochromic method. From the quantum-mechanical two-level model, it can be obtained that the μgβ value of DCDHF-2-V is 6520×10^-48esu atthe wavelength of 1064 nm.展开更多
An efficient method for quality control of Fructus Aurantii Immaturus (FAI),a famous traditional Chinese medicine (TCM) was established. A simple and reliable high-performance liquid chromatography-photodiode array de...An efficient method for quality control of Fructus Aurantii Immaturus (FAI),a famous traditional Chinese medicine (TCM) was established. A simple and reliable high-performance liquid chromatography-photodiode array detector (HPLC-DAD) procedure coupled with chemometric methods was developed for fingerprint analysis,qualitative analysis and quantitative determination of this herb. In qualitative and quantitative analyses,heuristic evolving latent projection (HELP) method was employed to resolve the overlapping peaks of the tested samples. Two bioactive components,namely hesperidin and naringin,are confirmed and determined,together with four flavonoids compounds tentatively identified including two new ones. From fingerprint analysis,the fingerprint data were processed with correlation coefficients for quantitative expression of their similarity and dissimilarity. The developed method based on an integration of chromatographic fingerprint and quantitative analysis is scientific,and the obtained results can be applied to the quality control of herb medicine.展开更多
Nitro and halogen substituted derivatives of the juglone naphthoquinone were synthesized and assayed for their antibacterial activity. 8-Nitrojuglone was obtained as the exclusive product from the direct nitration of ...Nitro and halogen substituted derivatives of the juglone naphthoquinone were synthesized and assayed for their antibacterial activity. 8-Nitrojuglone was obtained as the exclusive product from the direct nitration of juglone with nickel (Ⅱ) nitrate and p-toluenesulphonic acid. In addition, a series of five 8-halojuglone derivatives were synthesized via a solvent-free Friedel-Crafts acylation reaction. One of the acylation reactions afforded an anthraquinone-type derivative as the minor product. The 8-nitrojuglone derivative displayed the most notable activity against S. aureus. However, all of the 8-halojuglone derivatives were found to be less active than juglone against the bacteria assayed.展开更多
Despite significant therapeutic progress in recent years,inflammatory bowel disease(IBD),which includes Crohn’s disease and ulcerative colitis,remains a challenge regarding its pathogenesis and long-term complication...Despite significant therapeutic progress in recent years,inflammatory bowel disease(IBD),which includes Crohn’s disease and ulcerative colitis,remains a challenge regarding its pathogenesis and long-term complications.New concepts have emerged in the management of this disease,such as the"treat-totarget"concept,in which mucosal healing plays a key role in the evolution of IBD,the risk of recurrence and the need for surgery.Endoscopy is essential for the assessment of mucosal inflammation and plays a pivotal role in the analysis of mucosal healing in patients with IBD.Endoscopy is also essential in the detection of dysplasia and in the identification of the risk of colon cancer.The current surveillance strategy for dysplasia in IBD patients indicates white-light endoscopy with non-targeted biopsies.The new chromoendoscopy techniques provide substantial benefits for both clinicians and patients.Narrow-band imaging(NBI)has similar rates of dysplastic lesion detection as whitelight endoscopy,and it seems that NBI identifies more adenoma-like lesions.Because it is used instinctively by many endoscopists,the combination of these two techniques might improve the rate of dysplasia detection.Flexible spectral imaging color enhancement can help differentiate dysplastic and non-dysplastic lesions and can also predict the risk of recurrence,which allows us to modulate the treatment to gain better control of the disease.The combination of noninvasive serum and stool biomarkers with endoscopy will improve the monitoring and limit the evolution of IBD because it enables the use of a personalized approach to each patient based on that patient’s history and risk factors.展开更多
A new gray-spatial histogram is proposed, which incorporates spatial informatio n with gray compositions without sacrificing the robustness of traditional gray histograms. The purpose is to consider the representation...A new gray-spatial histogram is proposed, which incorporates spatial informatio n with gray compositions without sacrificing the robustness of traditional gray histograms. The purpose is to consider the representation role of gray compositi ons and spatial information simultaneously. Each entry in the gray-spatial hist ogram is the gray frequency and corresponding position information of images. In the experiments of sonar image recognition, the results show that the gray-spa tial histogram is effective in practical use.展开更多
This paper analyzes the language employed in the representations of women in Doukhobor Russian ritual texts called "ncanMbf' (psalms) from the viewpoint of linguistic text analysis performed in the Russian traditi...This paper analyzes the language employed in the representations of women in Doukhobor Russian ritual texts called "ncanMbf' (psalms) from the viewpoint of linguistic text analysis performed in the Russian tradition of folklore stylistics. While addressing the representations of Biblical female characters, such as the Holy Virgin Mary Magdalene, the Heavenly Bride, and the Whore of Babylon, along with the portrayals of Doukhobor and other women, the paper identifies stylistic features in their textual descriptions. The study establishes connections between Doukhobor texts and Russian folklore and liturgical tradition. The paper strives to identify the place of Doukhobor psalms as an integral part of the Russian literary and folklore heritage展开更多
An iridium (Ⅲ) bis[(4,6-difluorophenyl)pyridinato-N, C^2][6-(6'-(4"-( 5"-phenyl- 1", 3", 4"-oxadiazole-2"-yl) phenoxy) hexyloxy picolinate) was synthesized and characterized by IH NMR and elementary ...An iridium (Ⅲ) bis[(4,6-difluorophenyl)pyridinato-N, C^2][6-(6'-(4"-( 5"-phenyl- 1", 3", 4"-oxadiazole-2"-yl) phenoxy) hexyloxy picolinate) was synthesized and characterized by IH NMR and elementary analysis in order to study the effect of ancillary ligand of the oxadiazole-based picolinic acid derivative on optophysical properties of its iridium complex, and further to obtain an iridium complex with highly-efficient blue emission. The thermal stability, UV absorption and photoluminescent properties of this iridium complex were investigated. Compared with iridium (Ⅲ) bis[(4,6-difluorophenyl)pyridinato-N, C^2](picolinate) reported as a highly-efficient blue electroluminescent material, this iridium complex bearing an oxadiazole-based picolinic acid derivative presents higher thermal stability, more intense UV absorption at 291 nm and similar photoluminescent spectrum peaked at 469 nm. This indicates that tuning ancillary ligand of picolinic acid with an oxadiazole unit can improve the optophysical properties of its iridium complex.展开更多
A novel precision vibration-assisted micro-engraving system was developed by the integration of fast tool servo and ultrasonic elliptical vibration system, in which the flexure hinge was designed to avoid backlash and...A novel precision vibration-assisted micro-engraving system was developed by the integration of fast tool servo and ultrasonic elliptical vibration system, in which the flexure hinge was designed to avoid backlash and PID control algorithm was established to guarantee specific precision. Apart from experimental validation of the performance of the system, various micro-V-grooves cutting experiments on aluminum alloy, ferrous material and hard cutting material were performed, in which Kistler force sensor was used to measure cutting force. Through experiments, it was clear that the vibration-assisted micro-engraving system can ensure good quality of micro-V-grooves and reduce cutting force by about 60% compared with traditional removal process without ultrasonic vibration.展开更多
Triptolide is an important active component of Tripterygium wilfordii Hook F (TWHF) and possesses anti-inflammatory, immunosuppressive, male anti-fertility, and anticancer properties. A new method combining different ...Triptolide is an important active component of Tripterygium wilfordii Hook F (TWHF) and possesses anti-inflammatory, immunosuppressive, male anti-fertility, and anticancer properties. A new method combining different techniques, including solid-liquid extraction, liquid-liquid partition, column chromatography and high-speed counter-current chromatography (HSCCC) but avoiding the use of chloroform, was developed for the isolation and purification of triptolide from the leaves of TWHF. 48 mg of triptolide at 96.5% purity was obtained from 1 kg of air-dried leaves of TWHF.展开更多
Nowadays, the electrochemical water treatments are very important methods used for the removal of organic and inorganic impurities from fresh, drinking water and wastewater. The method consists of carrying out the oxi...Nowadays, the electrochemical water treatments are very important methods used for the removal of organic and inorganic impurities from fresh, drinking water and wastewater. The method consists of carrying out the oxidation reaction at the anode where pollutants are transferred into non-toxic substances, by decomposing into simpler compounds or transferring into oxidation form. RuO2-based Dimensional Stable Anode (DSA) is a technologically good and important electrode for water treatment because of its unique characteristics such as high thermal and chemical stability, low resistivity and low overpotential. This paper reviews the methods for fabricating RuO2-based electrodes that can be used in electrochemical water treatment. Depending on the different fabrication routes, RuO2 electrodes will possess the different electro-catalytic property and stability.展开更多
Thin cuprous oxide films have been prepared by chemical vapor deposition(pulsed spray evaporation-chemical vapor deposition)method without post-treatment.The synthesis of cuprous oxide was produced by applying a water...Thin cuprous oxide films have been prepared by chemical vapor deposition(pulsed spray evaporation-chemical vapor deposition)method without post-treatment.The synthesis of cuprous oxide was produced by applying a water strategy effect.Then,the effect of water on the morphology,topology,structure,optical properties and surface composition of the obtained films has been comprehensively investigated.The results reveal that a pure phase of Cu2O was obtained.The introduction of a small quantity of water in the liquid feedstock lowers the band gap energy from 2.16 eV to 2.04 eV.This finding was mainly related to the decrease of crystallite size due to the effect of water.The topology analyses,by using atomic force microscope,also revealed that surface roughness decreases with water addition,namely more uniform covered surface.Moreover,theoretical calculations based on density functional theory method were performed to understand the adsorption and reaction behaviors of water and ethanol on the Cu2O thin film surface.Formation mechanism of the Cu2O thin film was also suggested and discussed.展开更多
Chitosan is a biopolymer obtained from chitin, where the N-acetylglucosamine monomer is in its deacetylated form; this polymer is useful for a wide variety of industrial applications. The properties and uses of chitos...Chitosan is a biopolymer obtained from chitin, where the N-acetylglucosamine monomer is in its deacetylated form; this polymer is useful for a wide variety of industrial applications. The properties and uses of chitosan depend on its physical and chemical characteristics, which result from the treatments used for its production. In this study, we report the preparation and characterization ofchitosan oligosaccharides by a green synthesis from crystalline shrimp chitin, using a sequential enzyme treatment by chitinase and chitin deacetylase. Chitinases were purified from grapes and used to rupture the crystalline shrimp chitin structure, modifying the crystallinity index from 57.6% to 15.9%. The resultant polymers were deacetylated using a recombinant chitin deacetylase from Saccharomyces cerevisiae, which was cloned and expressed in Pichia pastoris. The chitosans produced showed an estimated DA (degree of acetylation) of approximately 20%, and the molecular weights ranged from -7,600 to -3,700 after treatment in pH 3.0 and pH 6.0 for 10 min and 40 min, respectively. Physical and chemical characterization of the products indicated that enzyme fragmentation of chitin probably makes the acetamide groups more accessible to deacetylation, forming homogeneous polymers that are free of hazardous sub-products, have defined low molecular weights, and are highly deacetylated.展开更多
A study was conducted to evaluate the genotoxicity, if any, of the permitted synthetic food colorants used in India. Eight synthetic food colorants namely Erythrosine (E 127), Tartrazine (E 102), Ponceau 4R (E 12...A study was conducted to evaluate the genotoxicity, if any, of the permitted synthetic food colorants used in India. Eight synthetic food colorants namely Erythrosine (E 127), Tartrazine (E 102), Ponceau 4R (E 124), Sunset Yellow FCF (E 110), Brilliant Blue FCF (E133), Fast Green FCF (E143), Carmoisine (E122) and Indigo Carmine (E132) and their combination are used in sweets namely Ladu, Jilebi and Halwa in Calicut and suburban areas of Kerala, in India. The genotoxicity of the colorants alone and in combinations at different concentrations were evaluated by Cytokinesis Block Micronucleus (CBMN) Assay. It was observed that all the above colorants and their combinations could cause genotoxicity to human lymphocytes even at the permissible concentration of 100 ppm as per PFA (Prevention of Food Adulteration) Act of India. The toxicity varied from dye to dye and was proportional to their concentration. Combination of colors showed more toxicity than the individual components. Toxicity could be reduced drastically by reducing the concentration of the dyes at least 50% below the permissible limit. Permitted synthetic food colorants even at the permissible limit should be used with caution. This study demonstrated the need for redefining the permissible limit of the food colorants based on Admissible Daily Intake (ADI) as being practiced in developed countries.展开更多
Objective:We aimed to establish a novel strategy for identifying key genes and active anti-inflammatory ingredients in Panax medicinal plants.Methods:First,fresh roots of 2-year-old Panax plants,including P.ginseng C....Objective:We aimed to establish a novel strategy for identifying key genes and active anti-inflammatory ingredients in Panax medicinal plants.Methods:First,fresh roots of 2-year-old Panax plants,including P.ginseng C.A.Mey.,P.quinquefolium L.,P.notoginseng(Burk.)F.H.Chen,P.japonicus C.A.Mey.,P.japonicus Mey.var.major(Burk.)C.Y.Wu et K.M.Feng,were selected as explants,and callus formation was induced under three experimental temperatures(17,24,and 30℃).Second,high-performance liquid chromatography-mass spectrometry was used to analyze the saponin content of the callus.Nitric oxide reduction efficacy was used for“component-efficacy”gray correlation analysis to find the active anti-inflammatory ingredients.Quantitative reverse-transcription polymerase chain reaction(qRT-PCR)was used to determine the inflammatory factors and verify the active ingredients’anti-inflammatory effects.Finally,qRT-PCR was used to detect the expression of key genes in the callus,and“gene-component”gray correlation analysis was used to examine the relationships between the regulatory pathway of the genes and the components.Results:Among the three experimental temperatures(17,24,and 30℃),the lowest temperature(17℃)is the most suitable for generating Panax callus.Lower-latitude native Panax notoginseng is more adaptable under high culture temperatures(24℃and 30℃)than other Panax plants.The ginsenoside contents of the callus of P.notoginseng and P.japonicus were the highest under similar climate conditions(17℃).Major anti-inflammatory components were G-Rh1,G-Rb1,G-Rg3,and G-Rh6/FloralGKa.CYP76A47 contributed to the accumulation of anti-inflammatory components.Conclusions:This study provides a strategy for the gene-component-efficacy correlational study of multi-component,multi-functional,and multi-purpose plants of the same genus.展开更多
The volatile oil of leaves and barks of Calycopteris floribunda was examined by gas chromatography-mass spectrometry (GC-MS). 52 volatile chemical components in leaves were identified. The antimicrobial assay of oils ...The volatile oil of leaves and barks of Calycopteris floribunda was examined by gas chromatography-mass spectrometry (GC-MS). 52 volatile chemical components in leaves were identified. The antimicrobial assay of oils in the leaves and barks was carried out by disk diffusion method in vitro. The major components (mass fraction) in leaves are caryophyllene oxide (13.79%),n-hexadecanoic acid (11.91%) and β-caryophyllene (10.45%). Ten constituents are identified accounting for about 99.98% of the total volatile oil in the bark. Among these components,n-hexadecanoic acid (59.18%),linolic acid (12.70%) and butyl octyl phthalate (8.21%) are the major constituents. The oils exhibit strong antimicrobial activity and display more potent against bacteria than fungi.展开更多
基金Supported by Natural Science Foundation of Guangxi Zhuang Autonomous Region(2011GXNSFF018006)Special Fund for Bagui Scholar Project~~
文摘[Objective] This study aimed to analyze the volatile constituents in Lonicera japonica Thunb. from different origins. [Method] HP-5MS capillary columns were used and column temperature was controlled by a program. MS analysis was performed with EI and quadruple mass analyzer. The volatile constituents in L. japonica Thunb. were identified by NIST02 and Wiley275 libraries, and their relative contents were determined with chromatographic peak area normalization method. [Result] According to GC-MS total ion-current chromatograms, 35 volatile constituents were identified in L. japonica Thunb. from Guangxi Zhuang Autonomous Region, mainly including methyl linolenate, n-hexadecanoic acid and ζ-muurolene; 18 volatile constituents were identified in L. japonica Thunb. from Hunan Province, mainly including n-hexadecanoic acid, linoleic acid and α-curcumene. [Conclusion] Main volatile constituents in L. japonica Thunb. from two different origins varied significantly.
文摘[Objective] This study was conducted to explore the internal relationship among root biological traits of sweetpotato, as well as the regularity in their formation and differentiation. [Method] The root traits of 10 sweetpotato cultivars were measured through hydroponic culture in a greenhouse and field survey, and then their correlations were analyzed by statistical methods. [Result] The root morphological traits of sweetpotato at seedling stage such as projected area, surface area, average diameter and volume processed the highest contribution rate (80.56%) 10 d after transplanting, and the contribution rate of root average diameter reached 27.79% 20 d after transplanting. Storage root fresh weight per plant shared extremely significant positive correlations with storage root fresh weight of penultimate node and storage root fresh weight of antepenultimate node, and a significant positive corre- lation with commercial storage root number, and a significant negative correlation with storage root number of penultimate node. Among them, the correlation coeffi- cient of storage root fresh weight per plant with storage root fresh weight of antepenultimate node was the highest (0.659 5). Fifteen days after transplanting, storage root fresh weight per plant had significant negative correlations with root projected area, surface area and volume. There was a significant positive correlation between root dry weight and storage root fresh weight per plant 25 d after transplanting. Root dry weight, volume, length, average diameter of sweetpotato seedlings had higher relational degrees with storage root fresh weight per plant. Ten and twenty days after transplanting were important time for the growth and differentiation of sweetpotato roots. In addition, node length and planting depth had certain influence on sweetpotato yield, and direct relationship existed between the seedling root biological traits and storage root yield of sweetpotato. [Conclusion] The results provide theoretical support for standard cultivation and new variety breeding of sweetpotato.
基金Supported by National Natural Science Foundation of China(31171787)College Student Innovation Fund of Hefei University of Technology(2012CXCY395)~~
文摘[Objective] This study aimed to analyze the volatile constituents in bamboo leaves. [Method] The volatile compositions in bamboo leaves were analyzed by headspace-gas chromatography-mass spectrometry (HS-GC/MS), and identified by searching their mass spectra in NIST database. The relative percentages of them were calculated by the GC peak areas. [Result] Fifty-three chemical constituents in bamboo leaves were separated. Among them, the main components were alcohols, ketones and aldehydes, and these compounds contained unsaturated bonds. [Con- clusion] HS-GC/MS was simple and less sample-demanding and can be used for rapid analysis of volatile constituents in bamboo leaves and provide scientific basis for further research and development of bamboo leaves.
文摘Nanoparticles of pure and Cu/Ag-doped CdS and ZnS have been synthesized via chemical bath deposition without using any capping or toxic reagents.The synthesis was carried out through a simple and less expensive green method.The XRD result shows that both pure CdS and ZnS and their doped derivatives are of high crystalline with hexagonal packing structure.The average crystalline size of all nanoparticles was calculated using Debye-Scherrer formula.The crystalline size of nanoparticles of pure samples varied with that of the doped sample.The average crystalline sizes of all nanoparticles are found to be in the range of 5.5-2.2 nm for CdS(from pure to doped) and 4.3-3.4 nm for ZnS,respectively.The band gap values obtained from UV-visible spectra are in the range of 3.5-2.1 e V for CdS and 3.3-2.7 e V for ZnS derivatives,respectively.The FTIR spectral data give characteristic peaks for Cd—S,Cu—S,Ag—S and Zn—S bonds and confirm the formation of respective nanoparticles.The peaks corresponding to the microstructural formation are also observed.The FE-SEM images show the granular morphological structure for all the samples.The agglomeration size of the samples in the range of 10-50 nm for CdS:Cu and 50-100 nm for ZnS:Cu is observed.
文摘A novel second-order nonlinear optical chromophore (DCDHF-2-V) was synthesized from 3-Hydroxy-3-methyl-2-butanae, propanedinitrile and 4-diethylaminobenzaldehyde by aldol condensation reaction. Molecular structural characterization was investigated by elemental analysis, FTIR, and 1H-NMR spectra. The melting point obtained from DSC thermogram was almost 251 ℃, and the compound shows a thermal stability up to 270 ℃. Second-order NLO properties of the chromophore were measured by solvatochromic method. From the quantum-mechanical two-level model, it can be obtained that the μgβ value of DCDHF-2-V is 6520×10^-48esu atthe wavelength of 1064 nm.
基金Project(20875104) supported by the National Natural Science Foundation of ChinaProject(10SDF22) supported by the Special Foundation of China Postdoctoral ScienceProject(201021200011) supported by the Advanced Research Plan of Central South University, China
文摘An efficient method for quality control of Fructus Aurantii Immaturus (FAI),a famous traditional Chinese medicine (TCM) was established. A simple and reliable high-performance liquid chromatography-photodiode array detector (HPLC-DAD) procedure coupled with chemometric methods was developed for fingerprint analysis,qualitative analysis and quantitative determination of this herb. In qualitative and quantitative analyses,heuristic evolving latent projection (HELP) method was employed to resolve the overlapping peaks of the tested samples. Two bioactive components,namely hesperidin and naringin,are confirmed and determined,together with four flavonoids compounds tentatively identified including two new ones. From fingerprint analysis,the fingerprint data were processed with correlation coefficients for quantitative expression of their similarity and dissimilarity. The developed method based on an integration of chromatographic fingerprint and quantitative analysis is scientific,and the obtained results can be applied to the quality control of herb medicine.
文摘Nitro and halogen substituted derivatives of the juglone naphthoquinone were synthesized and assayed for their antibacterial activity. 8-Nitrojuglone was obtained as the exclusive product from the direct nitration of juglone with nickel (Ⅱ) nitrate and p-toluenesulphonic acid. In addition, a series of five 8-halojuglone derivatives were synthesized via a solvent-free Friedel-Crafts acylation reaction. One of the acylation reactions afforded an anthraquinone-type derivative as the minor product. The 8-nitrojuglone derivative displayed the most notable activity against S. aureus. However, all of the 8-halojuglone derivatives were found to be less active than juglone against the bacteria assayed.
文摘Despite significant therapeutic progress in recent years,inflammatory bowel disease(IBD),which includes Crohn’s disease and ulcerative colitis,remains a challenge regarding its pathogenesis and long-term complications.New concepts have emerged in the management of this disease,such as the"treat-totarget"concept,in which mucosal healing plays a key role in the evolution of IBD,the risk of recurrence and the need for surgery.Endoscopy is essential for the assessment of mucosal inflammation and plays a pivotal role in the analysis of mucosal healing in patients with IBD.Endoscopy is also essential in the detection of dysplasia and in the identification of the risk of colon cancer.The current surveillance strategy for dysplasia in IBD patients indicates white-light endoscopy with non-targeted biopsies.The new chromoendoscopy techniques provide substantial benefits for both clinicians and patients.Narrow-band imaging(NBI)has similar rates of dysplastic lesion detection as whitelight endoscopy,and it seems that NBI identifies more adenoma-like lesions.Because it is used instinctively by many endoscopists,the combination of these two techniques might improve the rate of dysplasia detection.Flexible spectral imaging color enhancement can help differentiate dysplastic and non-dysplastic lesions and can also predict the risk of recurrence,which allows us to modulate the treatment to gain better control of the disease.The combination of noninvasive serum and stool biomarkers with endoscopy will improve the monitoring and limit the evolution of IBD because it enables the use of a personalized approach to each patient based on that patient’s history and risk factors.
文摘A new gray-spatial histogram is proposed, which incorporates spatial informatio n with gray compositions without sacrificing the robustness of traditional gray histograms. The purpose is to consider the representation role of gray compositi ons and spatial information simultaneously. Each entry in the gray-spatial hist ogram is the gray frequency and corresponding position information of images. In the experiments of sonar image recognition, the results show that the gray-spa tial histogram is effective in practical use.
文摘This paper analyzes the language employed in the representations of women in Doukhobor Russian ritual texts called "ncanMbf' (psalms) from the viewpoint of linguistic text analysis performed in the Russian tradition of folklore stylistics. While addressing the representations of Biblical female characters, such as the Holy Virgin Mary Magdalene, the Heavenly Bride, and the Whore of Babylon, along with the portrayals of Doukhobor and other women, the paper identifies stylistic features in their textual descriptions. The study establishes connections between Doukhobor texts and Russian folklore and liturgical tradition. The paper strives to identify the place of Doukhobor psalms as an integral part of the Russian literary and folklore heritage
基金Projects(20772101,50473046) supported by the National Natural Science Foundation of ChinaProject(2007FJ3017) supported by the Hunan Provincial Science Foundation, ChinaProject(07C764) supported by the Science Foundation of the Education Department of Hunan Province,China
文摘An iridium (Ⅲ) bis[(4,6-difluorophenyl)pyridinato-N, C^2][6-(6'-(4"-( 5"-phenyl- 1", 3", 4"-oxadiazole-2"-yl) phenoxy) hexyloxy picolinate) was synthesized and characterized by IH NMR and elementary analysis in order to study the effect of ancillary ligand of the oxadiazole-based picolinic acid derivative on optophysical properties of its iridium complex, and further to obtain an iridium complex with highly-efficient blue emission. The thermal stability, UV absorption and photoluminescent properties of this iridium complex were investigated. Compared with iridium (Ⅲ) bis[(4,6-difluorophenyl)pyridinato-N, C^2](picolinate) reported as a highly-efficient blue electroluminescent material, this iridium complex bearing an oxadiazole-based picolinic acid derivative presents higher thermal stability, more intense UV absorption at 291 nm and similar photoluminescent spectrum peaked at 469 nm. This indicates that tuning ancillary ligand of picolinic acid with an oxadiazole unit can improve the optophysical properties of its iridium complex.
基金Supported by National High Technology Research and Development Program of China ("863" Program, No. 2009AA043802)Japan Society for the Promotion of Science
文摘A novel precision vibration-assisted micro-engraving system was developed by the integration of fast tool servo and ultrasonic elliptical vibration system, in which the flexure hinge was designed to avoid backlash and PID control algorithm was established to guarantee specific precision. Apart from experimental validation of the performance of the system, various micro-V-grooves cutting experiments on aluminum alloy, ferrous material and hard cutting material were performed, in which Kistler force sensor was used to measure cutting force. Through experiments, it was clear that the vibration-assisted micro-engraving system can ensure good quality of micro-V-grooves and reduce cutting force by about 60% compared with traditional removal process without ultrasonic vibration.
基金Supported by the National Natural Science Foundation of China (20576113) Zhejiang Provincial Natural Science Foundation of China (R4090358)
文摘Triptolide is an important active component of Tripterygium wilfordii Hook F (TWHF) and possesses anti-inflammatory, immunosuppressive, male anti-fertility, and anticancer properties. A new method combining different techniques, including solid-liquid extraction, liquid-liquid partition, column chromatography and high-speed counter-current chromatography (HSCCC) but avoiding the use of chloroform, was developed for the isolation and purification of triptolide from the leaves of TWHF. 48 mg of triptolide at 96.5% purity was obtained from 1 kg of air-dried leaves of TWHF.
文摘Nowadays, the electrochemical water treatments are very important methods used for the removal of organic and inorganic impurities from fresh, drinking water and wastewater. The method consists of carrying out the oxidation reaction at the anode where pollutants are transferred into non-toxic substances, by decomposing into simpler compounds or transferring into oxidation form. RuO2-based Dimensional Stable Anode (DSA) is a technologically good and important electrode for water treatment because of its unique characteristics such as high thermal and chemical stability, low resistivity and low overpotential. This paper reviews the methods for fabricating RuO2-based electrodes that can be used in electrochemical water treatment. Depending on the different fabrication routes, RuO2 electrodes will possess the different electro-catalytic property and stability.
基金supported by the Ministry of Science and Technology of China(No.2017YFA0402800)the National Natural Science and Technology of China(No.91541102 and No.51476168)+2 种基金the support by Chinese Academy of Sciences for Senior International Scientists within President’s International Fellowship Initiative(PIFI)programthe financial support during his Ph.D.research stay at Bielefeld UniversityThe Moroccan institute of IRESEN is acknowledged for the financial support(Innowind13 Nanolubricant)
文摘Thin cuprous oxide films have been prepared by chemical vapor deposition(pulsed spray evaporation-chemical vapor deposition)method without post-treatment.The synthesis of cuprous oxide was produced by applying a water strategy effect.Then,the effect of water on the morphology,topology,structure,optical properties and surface composition of the obtained films has been comprehensively investigated.The results reveal that a pure phase of Cu2O was obtained.The introduction of a small quantity of water in the liquid feedstock lowers the band gap energy from 2.16 eV to 2.04 eV.This finding was mainly related to the decrease of crystallite size due to the effect of water.The topology analyses,by using atomic force microscope,also revealed that surface roughness decreases with water addition,namely more uniform covered surface.Moreover,theoretical calculations based on density functional theory method were performed to understand the adsorption and reaction behaviors of water and ethanol on the Cu2O thin film surface.Formation mechanism of the Cu2O thin film was also suggested and discussed.
文摘Chitosan is a biopolymer obtained from chitin, where the N-acetylglucosamine monomer is in its deacetylated form; this polymer is useful for a wide variety of industrial applications. The properties and uses of chitosan depend on its physical and chemical characteristics, which result from the treatments used for its production. In this study, we report the preparation and characterization ofchitosan oligosaccharides by a green synthesis from crystalline shrimp chitin, using a sequential enzyme treatment by chitinase and chitin deacetylase. Chitinases were purified from grapes and used to rupture the crystalline shrimp chitin structure, modifying the crystallinity index from 57.6% to 15.9%. The resultant polymers were deacetylated using a recombinant chitin deacetylase from Saccharomyces cerevisiae, which was cloned and expressed in Pichia pastoris. The chitosans produced showed an estimated DA (degree of acetylation) of approximately 20%, and the molecular weights ranged from -7,600 to -3,700 after treatment in pH 3.0 and pH 6.0 for 10 min and 40 min, respectively. Physical and chemical characterization of the products indicated that enzyme fragmentation of chitin probably makes the acetamide groups more accessible to deacetylation, forming homogeneous polymers that are free of hazardous sub-products, have defined low molecular weights, and are highly deacetylated.
文摘A study was conducted to evaluate the genotoxicity, if any, of the permitted synthetic food colorants used in India. Eight synthetic food colorants namely Erythrosine (E 127), Tartrazine (E 102), Ponceau 4R (E 124), Sunset Yellow FCF (E 110), Brilliant Blue FCF (E133), Fast Green FCF (E143), Carmoisine (E122) and Indigo Carmine (E132) and their combination are used in sweets namely Ladu, Jilebi and Halwa in Calicut and suburban areas of Kerala, in India. The genotoxicity of the colorants alone and in combinations at different concentrations were evaluated by Cytokinesis Block Micronucleus (CBMN) Assay. It was observed that all the above colorants and their combinations could cause genotoxicity to human lymphocytes even at the permissible concentration of 100 ppm as per PFA (Prevention of Food Adulteration) Act of India. The toxicity varied from dye to dye and was proportional to their concentration. Combination of colors showed more toxicity than the individual components. Toxicity could be reduced drastically by reducing the concentration of the dyes at least 50% below the permissible limit. Permitted synthetic food colorants even at the permissible limit should be used with caution. This study demonstrated the need for redefining the permissible limit of the food colorants based on Admissible Daily Intake (ADI) as being practiced in developed countries.
基金supported by National Natural Science Foundation of China grants(No.81773893)National Major Scientific and Technological Special Project for“Significant New Drugs Development”(No.2017ZX09301060001)+2 种基金Hubei Province Key R&D Programme(No.2020BED017 and 2020BGB004)Jiangxi Province“Thousand Talents Plan”of Scientific and Technological Innovation(No.JXSQ2019201105)Fundamental Research Funds for the Central Universities“South-Central University for Nationalities”(No.CZP20025 and No.CZP20047)
文摘Objective:We aimed to establish a novel strategy for identifying key genes and active anti-inflammatory ingredients in Panax medicinal plants.Methods:First,fresh roots of 2-year-old Panax plants,including P.ginseng C.A.Mey.,P.quinquefolium L.,P.notoginseng(Burk.)F.H.Chen,P.japonicus C.A.Mey.,P.japonicus Mey.var.major(Burk.)C.Y.Wu et K.M.Feng,were selected as explants,and callus formation was induced under three experimental temperatures(17,24,and 30℃).Second,high-performance liquid chromatography-mass spectrometry was used to analyze the saponin content of the callus.Nitric oxide reduction efficacy was used for“component-efficacy”gray correlation analysis to find the active anti-inflammatory ingredients.Quantitative reverse-transcription polymerase chain reaction(qRT-PCR)was used to determine the inflammatory factors and verify the active ingredients’anti-inflammatory effects.Finally,qRT-PCR was used to detect the expression of key genes in the callus,and“gene-component”gray correlation analysis was used to examine the relationships between the regulatory pathway of the genes and the components.Results:Among the three experimental temperatures(17,24,and 30℃),the lowest temperature(17℃)is the most suitable for generating Panax callus.Lower-latitude native Panax notoginseng is more adaptable under high culture temperatures(24℃and 30℃)than other Panax plants.The ginsenoside contents of the callus of P.notoginseng and P.japonicus were the highest under similar climate conditions(17℃).Major anti-inflammatory components were G-Rh1,G-Rb1,G-Rg3,and G-Rh6/FloralGKa.CYP76A47 contributed to the accumulation of anti-inflammatory components.Conclusions:This study provides a strategy for the gene-component-efficacy correlational study of multi-component,multi-functional,and multi-purpose plants of the same genus.
基金Project(2007-1718) supported by Development and Reform Commission of Yunnan Province, China
文摘The volatile oil of leaves and barks of Calycopteris floribunda was examined by gas chromatography-mass spectrometry (GC-MS). 52 volatile chemical components in leaves were identified. The antimicrobial assay of oils in the leaves and barks was carried out by disk diffusion method in vitro. The major components (mass fraction) in leaves are caryophyllene oxide (13.79%),n-hexadecanoic acid (11.91%) and β-caryophyllene (10.45%). Ten constituents are identified accounting for about 99.98% of the total volatile oil in the bark. Among these components,n-hexadecanoic acid (59.18%),linolic acid (12.70%) and butyl octyl phthalate (8.21%) are the major constituents. The oils exhibit strong antimicrobial activity and display more potent against bacteria than fungi.