In this paper, we present the development of flexible zinc–air battery. Multiwalled carbon nanotubes(MWCNTs) were added into electrodes to improve their performance. It was found that MWCNTs were effective conductive...In this paper, we present the development of flexible zinc–air battery. Multiwalled carbon nanotubes(MWCNTs) were added into electrodes to improve their performance. It was found that MWCNTs were effective conductive additive in anode as they bridged the zinc particles. Poly(3,4-ethylenedioxythiophene)polystyrene sulfonate(PEDOT:PSS) was applied as a co-binder to enhance both the conductivity and flexibility. A poly(acrylic acid)(PAA) and polyvinyl alcohol(PVA) coated paper separator was used to enhance the battery performance where the PVP–PAA layer facilitated electrolyte storage. The batteries remained functional under bending conditions and after bending. Multiple design optimizations were also carried out for storage and performance purposes.展开更多
Neutral aluminium alkyls are well known to act as ethylene oligomerization and polymerization catalysts and cocatalysts.On the basis of the full optimization of alkylaluminium compounds with Gaussian 98 program packag...Neutral aluminium alkyls are well known to act as ethylene oligomerization and polymerization catalysts and cocatalysts.On the basis of the full optimization of alkylaluminium compounds with Gaussian 98 program package at the B3LYP/6-31G＊＊ level,the selected structures and bonding energies were investigated extensively.The geometries and bonding energies of AlR3（R = H,CH3,C2H5,C3H7,C4H9） and Al（C2H5）2R＇（R＇ = C2H5,C3H7,C4H9,C5H11,C6H13） were investigated extensively,and we found that,along with the prolongation of carbon chains the terminal C-C bond is shortened gradually until to a constant value of about 0.1532 nm in C4H9;and the bonding energy almost remains constant.The dative bonding of C2H4 to Al（C2H5）3,whose bonding energy is only 15.30 kJ/mol,is very weak.展开更多
A new liquid-liquid microextraction method based on the solidification of floating organic drops coupled with gas chromatography was developed for the determination of trace benzene, toluene and xylene（BTX） in water...A new liquid-liquid microextraction method based on the solidification of floating organic drops coupled with gas chromatography was developed for the determination of trace benzene, toluene and xylene（BTX） in water samples. In the microextraction procedure, a microdrop of n-decanol was delivered to the surface of the analytes’ solution, and stirred for a desired time. Following the absolute extraction, the sample vial was cooled in an ice bath for 10 min. The solidified n-decanol was then transferred into a plastic tube and melted naturally; and 1 μL of it was injected into gas chromatography for analysis. Factors relevant to the extraction efficiency were studied and optimized. The optimal experimental conditions were： 15 μL of n-decanol as extractive solvent, 30 mL of solution containing analytes, no salt, the stirring rate 400 r/min, the extraction temperature 30 °C, and the extraction time 30 min. Under those optimized conditions, the detection limit（LOD） of analytes was in a range of 0.05―0.10 ng/mL by the developed method. A good linearity（r0.99） in a calibration range of 0.01―100 μg/mL was obtained. The recoveries of the real samples at different spiked levels of BTX were in the range from 92.2% to 103.4%.展开更多
Objective: To evaluate anti-Candida and anti-Cryptococcus activities of 15 nonalkaloidal compounds from Pterogyne nitens Tulasne(Leguminosae), a South American medicinal plant.Methods: Compounds were submitted to anti...Objective: To evaluate anti-Candida and anti-Cryptococcus activities of 15 nonalkaloidal compounds from Pterogyne nitens Tulasne(Leguminosae), a South American medicinal plant.Methods: Compounds were submitted to antifungal assays, using microdilution method described by Clinical and Laboratory Standards Institute document, with minor modifications. Five species of Candida and two species of Cryptococcus, including clinical isolates were screened. Antifungal activity was expressed by minimum inhibitory concentration(MIC). Amphotericin B and fluconazole were used as standard antifungal drugs.Results: Among tested compounds, six substances presented fungal growth inhibition(MIC < 31.2 mg/m L) [three flavone derivatives(1–3), a glycosylated flavonol derivative(5)and two phenolic acids(10 and 12)]. Sorbifolin(1), exhibited potent antifungal activity,demonstrating MIC value of 3.90 mg/m L against Candida glabrata ATCC 90030, Cryptococcus gattii 118 and fluconazole-resistant clinical isolate of Cryptococcus neoformans var. grubii. Pedalin(2) and nitensoside B(3), two glycosylated flavone derivatives, were active against Cryptococcus neoformans ATCC 90012(MIC = 7.80 mg/m L).Conclusions: Flavone derivatives from Pterogyne nitens can serve as prototypes for the design and development of innovative anti-Candida and anti-Cryptococcus hits.展开更多
For the need to protect the eco-environment and to strengthen environmental management in Lake Baiyangdian, water environment information aimed to get the water quality information more convenient and more intuitionis...For the need to protect the eco-environment and to strengthen environmental management in Lake Baiyangdian, water environment information aimed to get the water quality information more convenient and more intuitionistic was of significance. Based on massive monitoring data of Lake Baiyangdian and the important advantage of spatial analysis functions of GIS （geographical information system）, a system of B-WEIS （Baiyangdian water environment information system） was designed in the work. Component GIS of ArcEngine 9.3 GIS, combined with GIS and component technology, was used to research and develop the proposed system. This system realized different functions of management, data query, statistic analysis and visualization query to the Lake Baiyangdian water monitoring results. It also integrated with professional water quality model to realize evaluation of water quality and calculation of environmental capacity function. The designed system contributed to expand the management on Lake Baiyangdian more professional and available.展开更多
Lipases have important applications in biotechnological processes, motivating us to produce, purify, immobilize and perform a biochemical characterization of the lipase from Rhizomucor pusillus. The fungus was cultiva...Lipases have important applications in biotechnological processes, motivating us to produce, purify, immobilize and perform a biochemical characterization of the lipase from Rhizomucor pusillus. The fungus was cultivated by solid state fermentation producing lipolytic activity of about 0.5 U/mL(4U/g). A partial purification by gel filtration chromatography in Se-phacryl S-100 allowed obtaining a yield of about 85% and a purification factor of 5.7. Our results revealed that the purified enzyme is very stable with some significant differences in its properties when compared to crude extract. The crude enzyme extract has an optimum pH and temperature of 7.5 ° C and 40 ° C, respectively. After purification, a shift of the optimum pH from 7 to 8 was observed, as well as a rise in optimumtemperature to 60 ° C and an increase in stability. The enzyme was immobilized on CNBr-Agarose and Octyl-Agarose supports, having the highest immobilization yield of 94% in the second resin. The major advantage of immobilization in hydrophobic media such as Octyl is in its hyper activation, which in this case was over 200%, a very interesting finding. Another advantage of this type of immobilization is the possibility of using the derivatives in biotechnological applications, such as in oil enriched with omega-3 as the results obtained in this study display the hydrolysis of 40% EPA and 7% DHA from sardine oil, promising results compared to the literature.展开更多
In the H2SO4 medium and in the presence of dodecylbenzene sulfonic acid sodiumsalt (DBS), dimethyl yellow (R) could emit strong and stable solid substrate room temperature phosphorescence (RTP) on filter paper. And Na...In the H2SO4 medium and in the presence of dodecylbenzene sulfonic acid sodiumsalt (DBS), dimethyl yellow (R) could emit strong and stable solid substrate room temperature phosphorescence (RTP) on filter paper. And NaIO4 could oxidize R to cause the RTP quenching. Arsenic(V) could catalyze the reaction of NaIO4 oxidizing R, which caused the RTP sharply quenching. The reducing value of phosphorescence intensity (ΔIp) for the system with DBS is 3.3 times higher than that without DBS. Moreover, the ΔIp is proportional to the concentration of As(V). Based on the facts above, a new RTP quenching method for the determination of trace As(V) has been established.展开更多
A novel 1-D iodoplumbate hybrid, 2（Pb3I9）^3＊·3（C14H18N2）^2＋ 1, has been hydrothermally synthesized and characterized by IR spectra, TGA and single-crystal X-ray diffraction. Complex 1 crystallizes in monocl...A novel 1-D iodoplumbate hybrid, 2（Pb3I9）^3＊·3（C14H18N2）^2＋ 1, has been hydrothermally synthesized and characterized by IR spectra, TGA and single-crystal X-ray diffraction. Complex 1 crystallizes in monoclinic, space group P21/c, with a = 12.057（2）, b = 14.024（3）, c = 24.742（5） A, β = 90.48（3）°, V = 4183.6（14） A^3, Z = 4, R= 0.0477 and wR = 0.0800. The title compound consists of 1-D chains （Pb3I9）n^3n＊ parallel to the [100] direction and stacks of alkylated 4,4＇-bipyridium cations running along the [011] direction. Each anionic chain is surrounded by six arrays of alkylated 4,4＇-bipyridium cations through extensive C-H…I atypical hydrogen-bonding interactions to afford an interesting 3-D supramolecular network. Significant fluorescent property of the compound was observed at room temperature.展开更多
A new highly sensitive method （detection limit： 4.1 ag spofx, sample volume： 0.4 gL spot^·l） for the determination of trace Hg2^2＋ by catalytic solid substrate-room temperature phosphorimetry has been establ...A new highly sensitive method （detection limit： 4.1 ag spofx, sample volume： 0.4 gL spot^·l） for the determination of trace Hg2^2＋ by catalytic solid substrate-room temperature phosphorimetry has been established in this paper. This method has been successfully applied to determine trace Hg6^2＋ in water.展开更多
An initial model of the HBV epsilon RNA was built by the Biopolymer module of Insight II. While its three-dimensional structure was obtained through structure optimization based on molecular dynamics simulation, the t...An initial model of the HBV epsilon RNA was built by the Biopolymer module of Insight II. While its three-dimensional structure was obtained through structure optimization based on molecular dynamics simulation, the two active sites were found. A comparison with the experimental result indicated that the active sites may be the binding sites of the epsilon RNA in the RT-epsilon interaction. The result will be helpful to further discussion about the mechanism of RT-epsilon interaction and the study of HBV genome replication.展开更多
A new method for the determination of trace calcium by solid substrate-room temperature phosphorimetry is established. It is based on the fact that chromeazurols azurol S-phenanthroline-NaCMC (CAS-phen-NaCMC) system c...A new method for the determination of trace calcium by solid substrate-room temperature phosphorimetry is established. It is based on the fact that chromeazurols azurol S-phenanthroline-NaCMC (CAS-phen-NaCMC) system can emit strong and stable room temperature phosphorescence (RTP) on the solid substrate in the filter paper. Ca(2+) and phenanthroline can form complex ion Ca(phen)3(2+), which will form complex [Ca(phen)3(CAS)2] with CAS. In the result, the number of CAS molecules in each spot increased, causing sharp increase of the RTP signal of the CAS-phen-NaCMC system.展开更多
The pyrolysis of 1-hexene can act as a prototype of pyrolytic mechanism in petro- leum processing. Details of C-C bond cleavage in the 1-hexene pyrolysis were investigated at the MP2/6-31 I＋＋G^＊＊ basis set level. ...The pyrolysis of 1-hexene can act as a prototype of pyrolytic mechanism in petro- leum processing. Details of C-C bond cleavage in the 1-hexene pyrolysis were investigated at the MP2/6-31 I＋＋G^＊＊ basis set level. The equilibrium geometries and key thermodynamic parameters such as Gibbs free energies and thermal enthalpies were gained. Our theoretical results show that the entropy effect plays a significant role in dissociative processes. The dissociation of 1-hexene-4-yl radical into C4H6 and C2H5 is not an H-transfer and C-C rupture elementary reaction, but a process involving H-transfer and C-C rupture.展开更多
Solid waste and air pollution are never ending environmental problems that can be partially solved by turning waste into useful bio-products. In this study, enzymatic solutions were developed by formulating enzymatic ...Solid waste and air pollution are never ending environmental problems that can be partially solved by turning waste into useful bio-products. In this study, enzymatic solutions were developed by formulating enzymatic solutions from fish intestines and fruit peels. This aimed to help in biodegradation of organic solid wastes. Organic waste samples were treated with formulated enzymatic solutions for 7 days in aerated set-up for aerobic degradation. Biodegradability and odor of the waste samples were compared with commercial enzymatic solution. Determination of evolved carbon dioxide (CO2) using gravimetric analysis (GA) was used to determine the percent biodegradability, Dt, of organic solid waste and odor-ranking method was used to determine the odor intensity of the organic waste samples. The result showed that the weight loss and percentage biodegradability of organic waste sample treated with formulated enzymatic solution is comparable with that of the commercial enzymatic solution. In terms of odor intensity, waste treated with the product, formulated enzymatic solution (FES) is also comparable to the waste treated with commercial enzymatic solution. Thus, implying that the developed FES is as efficient as that of the commercial enzymatic solution. These significant results will be helpful to future researchers in providing ways on improving the degradation of organic solid waste and mitigating the increasing glitches on our environment. Enzyme kinetics, physical and chemical properties studies of the solution were recommended for future researchers to accurately determine the effectiveness of the formulated enzymatic solution in the degradation of organic solid waste.展开更多
A cobalt（11） complex containing mixed-ligands of 1,10-phenathroline（phen） and glycollic acid（GA）.｜Co（GA）_2（phen）｜ was synthesized and its structure was characterized by X-ray diffraction.The interaction of...A cobalt（11） complex containing mixed-ligands of 1,10-phenathroline（phen） and glycollic acid（GA）.｜Co（GA）_2（phen）｜ was synthesized and its structure was characterized by X-ray diffraction.The interaction of the complex with DNA was investigated by electronic absorption spectra and electrochemical methods.Electronic absorption spectrum experiments showed that after interaction with DNA.the characteristic absorption peaks of ｜Co（GA）_2（phen）｜ underwent hypochromic effect as well as redshift. Also,the binding strength of 3.8×10~4L/mol was estimated by titration method.Electrochemical assays revealed that the redox peak currents of the complex decreased obviously accompanied by a positive shift of the formal potential after association with DNA.All these results revealed that the synthesized cobalt complex bound with DNA via an intercalation mode.展开更多
A newfangled direct electrochemistry behavior of Cytochrome c (Cyt c) was found on glassy carbon (GC) electrode modified with the silicon dioxide (SiO2) nanoparticles by physical adsorption. A pair of stable and well-...A newfangled direct electrochemistry behavior of Cytochrome c (Cyt c) was found on glassy carbon (GC) electrode modified with the silicon dioxide (SiO2) nanoparticles by physical adsorption. A pair of stable and well-defined redox peaks of Cyt c′ quasi-reversible electrochemical reaction were obtained with a heterogeneous electron transfer rate constant of 1.66×10-3 cm/s and a formal potential of 0.069 V (vs. Ag/AgCl) (0.263 V versus NHE) in 0.1 mol/L pH 6.8 PBS. Both the size and the amount of SiO2 nanoparticles could influence the electron transfer between Cyt c and the electrode. Electrostatic interaction which is between the negative nanoparticle surface and positively charged amino acid residues on the Cyt c surface is of importance for the stability and reproducibility toward the direct electron transfer of Cyt c. It is suggested that the modification of SiO2 nanoparticles proposes a novel approach to realize the direct electrochemistry of proteins.展开更多
A Triton X-100-4.0G-D （4.0G-D refers to a 4.0-generation dendrimer） was brought forward as a new phosphorescence labeling reagent. Two types of specific affinity adsorption （AA） reactions （direct method and sandw...A Triton X-100-4.0G-D （4.0G-D refers to a 4.0-generation dendrimer） was brought forward as a new phosphorescence labeling reagent. Two types of specific affinity adsorption （AA） reactions （direct method and sandwich method） were carried out between the labeling product of Triton X-100-4：0G-D-Wheat germ agglutinin （WGA） and alkaline phosphatase （ALP）, the product of AA reaction preserved the good characteristics of room temperature phosphorescence （RTP） of 4.0G-D and △Ip of the product was proportional to the content of ALP. According to the fact stated above, a new method for the determination of trace ALP by affinity adsorption solid substrate-room temperature phosphorimetry （AA-SS-RTP） was established on the basis of WGA labeled with the Triton X-100-4.0G-D. The detection limits were 0.20 ag·spot^-1 （corresponding concentration： 5.0×10^-16 g·mL^-1, namely 5.0×10^-18 mol·L^-1） for a direct method and 0.14 ag·spot^-1 （corresponding concentration： 3.5×10^-16 g·mL^-1, namely 3.5×10^-18 mol·L^-1） for a sandwich method, respectively. For their high sensitivity, good repeatability and high accuracy, the direct method and sandwich method have been successfully appfied to determine the content of ALP in human serum, and the results were coincided with the clinical detection results of the enzyme-linked immunosorbent assay method by the Zhangzhou Hospital of Traditional Chinese Medicine. Meanwhile, the mechanism for the determination of trace ALP by AA-SS-RTP was discussed.展开更多
Although Cd is a pollutant of public health relevance,many dietary sources from which it can be absorbed into human tissues remain unknown.While it is well established that the biogeochemical cycle of Cd involves its ...Although Cd is a pollutant of public health relevance,many dietary sources from which it can be absorbed into human tissues remain unknown.While it is well established that the biogeochemical cycle of Cd involves its complexation with environment-derived ligands（e.g.,humic acids,HAs） and anthropogenic ones（e.g.,chelating agents,CAs）,the interaction of Cd with both of these ligands is less well understood.To gain insight,a HA–Cd complex was injected on a size-exclusion chromatography（SEC） column coupled on-line with a flame atomic absorption spectrometer（FAAS） using 10 mmol/L Tris buffer（pH 8.0） as the mobile phase.This approach allowed us to observe the intact HA–Cd complex and the retention behavior of Cd as a function of 2–20 μmol/L concentrations of ethylenediaminetetraacetic acid（EDTA）,diethylenetriaminepentaacetic acid（DTPA） or methylglycinediacetic acid（MGDA） that were added to the mobile phase.An increase of the retention time of Cd was indicative of a partial or complete abstraction of Cd from HA.Our results revealed that all CAs abstracted Cd from the HA–Cd complex at concentrations of 5 μmol/L,while MGDA and DTPA were effective at 2 μmol/L.The bioavailability of some of the on-column formed CA–Cd complexes explains the previously reported increased accumulation of Cd in periphyton in the ecosystem downstream of wastewater treatment plants.In addition,our results imply that the use of effluents which contain CAs and Cd for the irrigation of food crops can introduce Cd into the food supply and compromise food safety.展开更多
Maintaining healthy watershed is pivotal to ensure sustainability in water resources thereby improving the carrying capacity of the earth.Understanding and identifying the spatial variability of hydrologically sensiti...Maintaining healthy watershed is pivotal to ensure sustainability in water resources thereby improving the carrying capacity of the earth.Understanding and identifying the spatial variability of hydrologically sensitive areas(HSAs)in a watershed is an important step to prioritizing the landscape to maintain water sustainability with limited resources.A spatial technique known as Soil Topographic Index(STI)was used to identify HSAs in the landscape.This study was conducted in Clinton and Tewksbury Townships in New Jersey,United States.Three different scenarios(STI>=9,STI>=10,and STI>=11)were conducted to understand the spatial distribution of HSAs in the watershed.The following conclusions were derived from this study.Firstly,a more detail representation of HSAs in the watershed was observed when applying the STI technique with a fine scale light detection and ranging(LiDAR)digitial elevation model.Secondly,all three scenarios consistently identified perennial stream corridors as HSAs;therefore,it is important to protect perennial stream corridors through implementation of various land use controls.Thirdly,this study analyzes the land use pattern of HSAs under the three scenarios and identifies the HSAs for high intensity land uses such as agriculture and urban to be the high priority locations for implementing best management practices for water quality improvements.The procedures developed in this study can be applied to watersheds in other parts of the world with similar physiographic characteristics.展开更多
As an antibiotic,sulfadiazine has posed a serious threat to humans and ecosystems due to its chronic toxicity.The advanced oxidation processes (AOPs) via heterogeneous catalytic activation of peroxymonosulfate (PMS) h...As an antibiotic,sulfadiazine has posed a serious threat to humans and ecosystems due to its chronic toxicity.The advanced oxidation processes (AOPs) via heterogeneous catalytic activation of peroxymonosulfate (PMS) have significant potential for the degradation of antibiotics.However,there are multiple restrictions including non-specifically binding to target contaminants,which would deplete oxidation capacity,and lacking energy effectiveness due to inefficient utilization of reactive oxygen species (ROS).To overcome these obstacles,we adopted the“bait-hook&destroy”strategy in this study.Herein,we synthesized a novel micrometer-sized Ni OOH hierarchical spheres assembled from nanosheets,which have relatively large specific surface areas and yield specified cavities to“bait-hook”sulfadiazine and PMS onto the surface cavities.This process was further conductive to effective generation of ROS and subsequently“destruction”of sulfadiazine with elevated mass transformation rate.20.4%of sulfadiazine can adsorb to Ni OOH surface in less than 30 min (0.0051 min^(-1)),and then sulfadiazine was completely degraded in 90min intervals in the Ni OOH/PMS system.The degradation rate constant (k=0.0537 min^(-1)) was about5.3,2.5 and 2.2 times higher than that in Ni_(2)O_(3)/PMS,NiO/PMS and Ni(OH)_(2)/PMS system,respectively.This was ascribed to the synergistic catalytic oxidation and adsorption process occurred on the surface of Ni OOH.Appreciably,there were both non-radicals (^(1)O_(2)) and radicals (O_(2)^(·-)and SO_(4)^(·-)) involved in the Ni OOH/PMS system,and^(1)O_(2)was distinguished as the dominated ROS for degradation of sulfadiazine.This study provides a novel strategy via synergistic adsorption and catalytic oxidation,and indicates that the micrometer-sized Ni OOH hierarchical sphere as heterogeneous catalyst is an attractive candidate for potential application of the SR-AOPs technology in water treatment.展开更多
A novel drug agent named norfloxacin biomonomer was developed in order to solve the problem of low drug content,uneven drug distribution,low molecular weight,and wide molecular weight distribution of polymer drug,base...A novel drug agent named norfloxacin biomonomer was developed in order to solve the problem of low drug content,uneven drug distribution,low molecular weight,and wide molecular weight distribution of polymer drug,based on polyurethane,which was used as an antibacterial agent to control the bacterial infection associated with biofilm formation on polymeric materials used in biologic environments.In this research,norfloxacin biomonomer was synthesized by esterifying the compound of norfloxacin.High-performance liquid chromatography system was used to analyze the purity of the final product and intermediate products,and Fourier transform infrared spectrometer and mass spectrum were used to verify the final product and intermediate products.The results showed that the objective product was developed successfully.The final product of norfloxacin biomonomer could be incorporated into the polyurethane as chain extender.展开更多
文摘In this paper, we present the development of flexible zinc–air battery. Multiwalled carbon nanotubes(MWCNTs) were added into electrodes to improve their performance. It was found that MWCNTs were effective conductive additive in anode as they bridged the zinc particles. Poly(3,4-ethylenedioxythiophene)polystyrene sulfonate(PEDOT:PSS) was applied as a co-binder to enhance both the conductivity and flexibility. A poly(acrylic acid)(PAA) and polyvinyl alcohol(PVA) coated paper separator was used to enhance the battery performance where the PVP–PAA layer facilitated electrolyte storage. The batteries remained functional under bending conditions and after bending. Multiple design optimizations were also carried out for storage and performance purposes.
基金supported by the National Natural Science Foundation of China (No. 10674099)
文摘Neutral aluminium alkyls are well known to act as ethylene oligomerization and polymerization catalysts and cocatalysts.On the basis of the full optimization of alkylaluminium compounds with Gaussian 98 program package at the B3LYP/6-31G＊＊ level,the selected structures and bonding energies were investigated extensively.The geometries and bonding energies of AlR3（R = H,CH3,C2H5,C3H7,C4H9） and Al（C2H5）2R＇（R＇ = C2H5,C3H7,C4H9,C5H11,C6H13） were investigated extensively,and we found that,along with the prolongation of carbon chains the terminal C-C bond is shortened gradually until to a constant value of about 0.1532 nm in C4H9;and the bonding energy almost remains constant.The dative bonding of C2H4 to Al（C2H5）3,whose bonding energy is only 15.30 kJ/mol,is very weak.
基金Supported by the National Natural Science Foundation of China(No.21105088)the Program for Science and Technology Projects of the Education Department of Fujian Province,China(No.JA10211)
文摘A new liquid-liquid microextraction method based on the solidification of floating organic drops coupled with gas chromatography was developed for the determination of trace benzene, toluene and xylene（BTX） in water samples. In the microextraction procedure, a microdrop of n-decanol was delivered to the surface of the analytes’ solution, and stirred for a desired time. Following the absolute extraction, the sample vial was cooled in an ice bath for 10 min. The solidified n-decanol was then transferred into a plastic tube and melted naturally; and 1 μL of it was injected into gas chromatography for analysis. Factors relevant to the extraction efficiency were studied and optimized. The optimal experimental conditions were： 15 μL of n-decanol as extractive solvent, 30 mL of solution containing analytes, no salt, the stirring rate 400 r/min, the extraction temperature 30 °C, and the extraction time 30 min. Under those optimized conditions, the detection limit（LOD） of analytes was in a range of 0.05―0.10 ng/mL by the developed method. A good linearity（r0.99） in a calibration range of 0.01―100 μg/mL was obtained. The recoveries of the real samples at different spiked levels of BTX were in the range from 92.2% to 103.4%.
基金Supported by Support Foundation of Sao Paulo Research(FAPESP,Grant No.2014/05445-3)National Council of Technological and Scientific Development(CNPq)Office of Research of the Sao Paulo State University
文摘Objective: To evaluate anti-Candida and anti-Cryptococcus activities of 15 nonalkaloidal compounds from Pterogyne nitens Tulasne(Leguminosae), a South American medicinal plant.Methods: Compounds were submitted to antifungal assays, using microdilution method described by Clinical and Laboratory Standards Institute document, with minor modifications. Five species of Candida and two species of Cryptococcus, including clinical isolates were screened. Antifungal activity was expressed by minimum inhibitory concentration(MIC). Amphotericin B and fluconazole were used as standard antifungal drugs.Results: Among tested compounds, six substances presented fungal growth inhibition(MIC < 31.2 mg/m L) [three flavone derivatives(1–3), a glycosylated flavonol derivative(5)and two phenolic acids(10 and 12)]. Sorbifolin(1), exhibited potent antifungal activity,demonstrating MIC value of 3.90 mg/m L against Candida glabrata ATCC 90030, Cryptococcus gattii 118 and fluconazole-resistant clinical isolate of Cryptococcus neoformans var. grubii. Pedalin(2) and nitensoside B(3), two glycosylated flavone derivatives, were active against Cryptococcus neoformans ATCC 90012(MIC = 7.80 mg/m L).Conclusions: Flavone derivatives from Pterogyne nitens can serve as prototypes for the design and development of innovative anti-Candida and anti-Cryptococcus hits.
文摘For the need to protect the eco-environment and to strengthen environmental management in Lake Baiyangdian, water environment information aimed to get the water quality information more convenient and more intuitionistic was of significance. Based on massive monitoring data of Lake Baiyangdian and the important advantage of spatial analysis functions of GIS （geographical information system）, a system of B-WEIS （Baiyangdian water environment information system） was designed in the work. Component GIS of ArcEngine 9.3 GIS, combined with GIS and component technology, was used to research and develop the proposed system. This system realized different functions of management, data query, statistic analysis and visualization query to the Lake Baiyangdian water monitoring results. It also integrated with professional water quality model to realize evaluation of water quality and calculation of environmental capacity function. The designed system contributed to expand the management on Lake Baiyangdian more professional and available.
基金FAPESP and CNPq(Brazil)for financial supportConsolider INGENIO 2010 CSD2007-00063 FUNC-FOOD(CICYT),the Spanish Ministry of Science and Innovation.
文摘Lipases have important applications in biotechnological processes, motivating us to produce, purify, immobilize and perform a biochemical characterization of the lipase from Rhizomucor pusillus. The fungus was cultivated by solid state fermentation producing lipolytic activity of about 0.5 U/mL(4U/g). A partial purification by gel filtration chromatography in Se-phacryl S-100 allowed obtaining a yield of about 85% and a purification factor of 5.7. Our results revealed that the purified enzyme is very stable with some significant differences in its properties when compared to crude extract. The crude enzyme extract has an optimum pH and temperature of 7.5 ° C and 40 ° C, respectively. After purification, a shift of the optimum pH from 7 to 8 was observed, as well as a rise in optimumtemperature to 60 ° C and an increase in stability. The enzyme was immobilized on CNBr-Agarose and Octyl-Agarose supports, having the highest immobilization yield of 94% in the second resin. The major advantage of immobilization in hydrophobic media such as Octyl is in its hyper activation, which in this case was over 200%, a very interesting finding. Another advantage of this type of immobilization is the possibility of using the derivatives in biotechnological applications, such as in oil enriched with omega-3 as the results obtained in this study display the hydrolysis of 40% EPA and 7% DHA from sardine oil, promising results compared to the literature.
文摘In the H2SO4 medium and in the presence of dodecylbenzene sulfonic acid sodiumsalt (DBS), dimethyl yellow (R) could emit strong and stable solid substrate room temperature phosphorescence (RTP) on filter paper. And NaIO4 could oxidize R to cause the RTP quenching. Arsenic(V) could catalyze the reaction of NaIO4 oxidizing R, which caused the RTP sharply quenching. The reducing value of phosphorescence intensity (ΔIp) for the system with DBS is 3.3 times higher than that without DBS. Moreover, the ΔIp is proportional to the concentration of As(V). Based on the facts above, a new RTP quenching method for the determination of trace As(V) has been established.
基金supported by the Natural Science Foundation of Fujian Province (008 J0172)Innovation Project of Fujian Province (2007F3107)National Natural Science Foundation of China (20705031)
文摘A novel 1-D iodoplumbate hybrid, 2（Pb3I9）^3＊·3（C14H18N2）^2＋ 1, has been hydrothermally synthesized and characterized by IR spectra, TGA and single-crystal X-ray diffraction. Complex 1 crystallizes in monoclinic, space group P21/c, with a = 12.057（2）, b = 14.024（3）, c = 24.742（5） A, β = 90.48（3）°, V = 4183.6（14） A^3, Z = 4, R= 0.0477 and wR = 0.0800. The title compound consists of 1-D chains （Pb3I9）n^3n＊ parallel to the [100] direction and stacks of alkylated 4,4＇-bipyridium cations running along the [011] direction. Each anionic chain is surrounded by six arrays of alkylated 4,4＇-bipyridium cations through extensive C-H…I atypical hydrogen-bonding interactions to afford an interesting 3-D supramolecular network. Significant fluorescent property of the compound was observed at room temperature.
基金supported by Fujian Province Natural Science Foundation(No.C 0510028,D 0510027).
文摘A new highly sensitive method （detection limit： 4.1 ag spofx, sample volume： 0.4 gL spot^·l） for the determination of trace Hg2^2＋ by catalytic solid substrate-room temperature phosphorimetry has been established in this paper. This method has been successfully applied to determine trace Hg6^2＋ in water.
基金supported by a grant from YNZY(No.2007JC02) to H.C.
文摘An initial model of the HBV epsilon RNA was built by the Biopolymer module of Insight II. While its three-dimensional structure was obtained through structure optimization based on molecular dynamics simulation, the two active sites were found. A comparison with the experimental result indicated that the active sites may be the binding sites of the epsilon RNA in the RT-epsilon interaction. The result will be helpful to further discussion about the mechanism of RT-epsilon interaction and the study of HBV genome replication.
文摘A new method for the determination of trace calcium by solid substrate-room temperature phosphorimetry is established. It is based on the fact that chromeazurols azurol S-phenanthroline-NaCMC (CAS-phen-NaCMC) system can emit strong and stable room temperature phosphorescence (RTP) on the solid substrate in the filter paper. Ca(2+) and phenanthroline can form complex ion Ca(phen)3(2+), which will form complex [Ca(phen)3(CAS)2] with CAS. In the result, the number of CAS molecules in each spot increased, causing sharp increase of the RTP signal of the CAS-phen-NaCMC system.
基金financially supported by the National Natural Science Foundation of China (No. 11174215)the Foundation of Shandong Province (ZR2012BL10)
文摘The pyrolysis of 1-hexene can act as a prototype of pyrolytic mechanism in petro- leum processing. Details of C-C bond cleavage in the 1-hexene pyrolysis were investigated at the MP2/6-31 I＋＋G^＊＊ basis set level. The equilibrium geometries and key thermodynamic parameters such as Gibbs free energies and thermal enthalpies were gained. Our theoretical results show that the entropy effect plays a significant role in dissociative processes. The dissociation of 1-hexene-4-yl radical into C4H6 and C2H5 is not an H-transfer and C-C rupture elementary reaction, but a process involving H-transfer and C-C rupture.
文摘Solid waste and air pollution are never ending environmental problems that can be partially solved by turning waste into useful bio-products. In this study, enzymatic solutions were developed by formulating enzymatic solutions from fish intestines and fruit peels. This aimed to help in biodegradation of organic solid wastes. Organic waste samples were treated with formulated enzymatic solutions for 7 days in aerated set-up for aerobic degradation. Biodegradability and odor of the waste samples were compared with commercial enzymatic solution. Determination of evolved carbon dioxide (CO2) using gravimetric analysis (GA) was used to determine the percent biodegradability, Dt, of organic solid waste and odor-ranking method was used to determine the odor intensity of the organic waste samples. The result showed that the weight loss and percentage biodegradability of organic waste sample treated with formulated enzymatic solution is comparable with that of the commercial enzymatic solution. In terms of odor intensity, waste treated with the product, formulated enzymatic solution (FES) is also comparable to the waste treated with commercial enzymatic solution. Thus, implying that the developed FES is as efficient as that of the commercial enzymatic solution. These significant results will be helpful to future researchers in providing ways on improving the degradation of organic solid waste and mitigating the increasing glitches on our environment. Enzyme kinetics, physical and chemical properties studies of the solution were recommended for future researchers to accurately determine the effectiveness of the formulated enzymatic solution in the degradation of organic solid waste.
基金supported by the National Natural Science Foundation of China(No.20805041)Training Programme Foundation for Excellent Youth Researching Talents of Fujian's Universities(No.JA10201)+1 种基金Key Provincial University Project of Fujian(No.2008F5064)Research Foundation of Fujian Education Department (No.JA09170)
文摘A cobalt（11） complex containing mixed-ligands of 1,10-phenathroline（phen） and glycollic acid（GA）.｜Co（GA）_2（phen）｜ was synthesized and its structure was characterized by X-ray diffraction.The interaction of the complex with DNA was investigated by electronic absorption spectra and electrochemical methods.Electronic absorption spectrum experiments showed that after interaction with DNA.the characteristic absorption peaks of ｜Co（GA）_2（phen）｜ underwent hypochromic effect as well as redshift. Also,the binding strength of 3.8×10~4L/mol was estimated by titration method.Electrochemical assays revealed that the redox peak currents of the complex decreased obviously accompanied by a positive shift of the formal potential after association with DNA.All these results revealed that the synthesized cobalt complex bound with DNA via an intercalation mode.
基金Supported by the Fundamental Research Program 973 Program (Grant No. G2000026408)High Technology Research Program of Science and Technology Ministry of China 863 Program (Grant Nos. 2001AA323060, 2003AA517062)+2 种基金the National Natural Science Foundation of China (Grant No. 20373062)Key Pro-ject (Grant No.20433060)Research Foundation of State Key Laboratory of Physical Chemistry of Solid Surface (Grant No. 200407)
文摘A newfangled direct electrochemistry behavior of Cytochrome c (Cyt c) was found on glassy carbon (GC) electrode modified with the silicon dioxide (SiO2) nanoparticles by physical adsorption. A pair of stable and well-defined redox peaks of Cyt c′ quasi-reversible electrochemical reaction were obtained with a heterogeneous electron transfer rate constant of 1.66×10-3 cm/s and a formal potential of 0.069 V (vs. Ag/AgCl) (0.263 V versus NHE) in 0.1 mol/L pH 6.8 PBS. Both the size and the amount of SiO2 nanoparticles could influence the electron transfer between Cyt c and the electrode. Electrostatic interaction which is between the negative nanoparticle surface and positively charged amino acid residues on the Cyt c surface is of importance for the stability and reproducibility toward the direct electron transfer of Cyt c. It is suggested that the modification of SiO2 nanoparticles proposes a novel approach to realize the direct electrochemistry of proteins.
基金Project supported by Fujian Province Natural Science Foundation （Nos. C0510028, D0510027, 2006J0386）.
文摘A Triton X-100-4.0G-D （4.0G-D refers to a 4.0-generation dendrimer） was brought forward as a new phosphorescence labeling reagent. Two types of specific affinity adsorption （AA） reactions （direct method and sandwich method） were carried out between the labeling product of Triton X-100-4：0G-D-Wheat germ agglutinin （WGA） and alkaline phosphatase （ALP）, the product of AA reaction preserved the good characteristics of room temperature phosphorescence （RTP） of 4.0G-D and △Ip of the product was proportional to the content of ALP. According to the fact stated above, a new method for the determination of trace ALP by affinity adsorption solid substrate-room temperature phosphorimetry （AA-SS-RTP） was established on the basis of WGA labeled with the Triton X-100-4.0G-D. The detection limits were 0.20 ag·spot^-1 （corresponding concentration： 5.0×10^-16 g·mL^-1, namely 5.0×10^-18 mol·L^-1） for a direct method and 0.14 ag·spot^-1 （corresponding concentration： 3.5×10^-16 g·mL^-1, namely 3.5×10^-18 mol·L^-1） for a sandwich method, respectively. For their high sensitivity, good repeatability and high accuracy, the direct method and sandwich method have been successfully appfied to determine the content of ALP in human serum, and the results were coincided with the clinical detection results of the enzyme-linked immunosorbent assay method by the Zhangzhou Hospital of Traditional Chinese Medicine. Meanwhile, the mechanism for the determination of trace ALP by AA-SS-RTP was discussed.
基金funded by the Natural Sciences and Engineering Research Council(NSERC)of Canada
文摘Although Cd is a pollutant of public health relevance,many dietary sources from which it can be absorbed into human tissues remain unknown.While it is well established that the biogeochemical cycle of Cd involves its complexation with environment-derived ligands（e.g.,humic acids,HAs） and anthropogenic ones（e.g.,chelating agents,CAs）,the interaction of Cd with both of these ligands is less well understood.To gain insight,a HA–Cd complex was injected on a size-exclusion chromatography（SEC） column coupled on-line with a flame atomic absorption spectrometer（FAAS） using 10 mmol/L Tris buffer（pH 8.0） as the mobile phase.This approach allowed us to observe the intact HA–Cd complex and the retention behavior of Cd as a function of 2–20 μmol/L concentrations of ethylenediaminetetraacetic acid（EDTA）,diethylenetriaminepentaacetic acid（DTPA） or methylglycinediacetic acid（MGDA） that were added to the mobile phase.An increase of the retention time of Cd was indicative of a partial or complete abstraction of Cd from HA.Our results revealed that all CAs abstracted Cd from the HA–Cd complex at concentrations of 5 μmol/L,while MGDA and DTPA were effective at 2 μmol/L.The bioavailability of some of the on-column formed CA–Cd complexes explains the previously reported increased accumulation of Cd in periphyton in the ecosystem downstream of wastewater treatment plants.In addition,our results imply that the use of effluents which contain CAs and Cd for the irrigation of food crops can introduce Cd into the food supply and compromise food safety.
基金the funding support to New Jersey Institute of Technology by the USDA National Institute of Food and Agriculture(Grant number NJW-2012-67019-19348).
文摘Maintaining healthy watershed is pivotal to ensure sustainability in water resources thereby improving the carrying capacity of the earth.Understanding and identifying the spatial variability of hydrologically sensitive areas(HSAs)in a watershed is an important step to prioritizing the landscape to maintain water sustainability with limited resources.A spatial technique known as Soil Topographic Index(STI)was used to identify HSAs in the landscape.This study was conducted in Clinton and Tewksbury Townships in New Jersey,United States.Three different scenarios(STI>=9,STI>=10,and STI>=11)were conducted to understand the spatial distribution of HSAs in the watershed.The following conclusions were derived from this study.Firstly,a more detail representation of HSAs in the watershed was observed when applying the STI technique with a fine scale light detection and ranging(LiDAR)digitial elevation model.Secondly,all three scenarios consistently identified perennial stream corridors as HSAs;therefore,it is important to protect perennial stream corridors through implementation of various land use controls.Thirdly,this study analyzes the land use pattern of HSAs under the three scenarios and identifies the HSAs for high intensity land uses such as agriculture and urban to be the high priority locations for implementing best management practices for water quality improvements.The procedures developed in this study can be applied to watersheds in other parts of the world with similar physiographic characteristics.
基金funded by the National Key R&D Program of China (No.2018YFC0406503)the National Natural Science Foundation of China (No.52070086)+1 种基金the Natural Science Foundation of Jilin Provincial Science & Technology Department (No.20200403034SF)the Open Project Program of Engineering Research Center of Groundwater Pollution Control and Remediation,Ministry of Education。
文摘As an antibiotic,sulfadiazine has posed a serious threat to humans and ecosystems due to its chronic toxicity.The advanced oxidation processes (AOPs) via heterogeneous catalytic activation of peroxymonosulfate (PMS) have significant potential for the degradation of antibiotics.However,there are multiple restrictions including non-specifically binding to target contaminants,which would deplete oxidation capacity,and lacking energy effectiveness due to inefficient utilization of reactive oxygen species (ROS).To overcome these obstacles,we adopted the“bait-hook&destroy”strategy in this study.Herein,we synthesized a novel micrometer-sized Ni OOH hierarchical spheres assembled from nanosheets,which have relatively large specific surface areas and yield specified cavities to“bait-hook”sulfadiazine and PMS onto the surface cavities.This process was further conductive to effective generation of ROS and subsequently“destruction”of sulfadiazine with elevated mass transformation rate.20.4%of sulfadiazine can adsorb to Ni OOH surface in less than 30 min (0.0051 min^(-1)),and then sulfadiazine was completely degraded in 90min intervals in the Ni OOH/PMS system.The degradation rate constant (k=0.0537 min^(-1)) was about5.3,2.5 and 2.2 times higher than that in Ni_(2)O_(3)/PMS,NiO/PMS and Ni(OH)_(2)/PMS system,respectively.This was ascribed to the synergistic catalytic oxidation and adsorption process occurred on the surface of Ni OOH.Appreciably,there were both non-radicals (^(1)O_(2)) and radicals (O_(2)^(·-)and SO_(4)^(·-)) involved in the Ni OOH/PMS system,and^(1)O_(2)was distinguished as the dominated ROS for degradation of sulfadiazine.This study provides a novel strategy via synergistic adsorption and catalytic oxidation,and indicates that the micrometer-sized Ni OOH hierarchical sphere as heterogeneous catalyst is an attractive candidate for potential application of the SR-AOPs technology in water treatment.
基金supported by the program of the Fujian Provincial Department of Science&Technology(No.2006I0019)supported by the Science and Technology Department of Fujian Province Subsidization Provincial University Projects(2008F50502)the Fujian Provincial Key Laboratory of Polymer Materials.
文摘A novel drug agent named norfloxacin biomonomer was developed in order to solve the problem of low drug content,uneven drug distribution,low molecular weight,and wide molecular weight distribution of polymer drug,based on polyurethane,which was used as an antibacterial agent to control the bacterial infection associated with biofilm formation on polymeric materials used in biologic environments.In this research,norfloxacin biomonomer was synthesized by esterifying the compound of norfloxacin.High-performance liquid chromatography system was used to analyze the purity of the final product and intermediate products,and Fourier transform infrared spectrometer and mass spectrum were used to verify the final product and intermediate products.The results showed that the objective product was developed successfully.The final product of norfloxacin biomonomer could be incorporated into the polyurethane as chain extender.
