Utilizing solvent extraction to separate alkanes and olefins from catalytic light gasoline is an effective method for maximizing the utility of gasoline fractions.This study presents the determination of liquid-liquid...Utilizing solvent extraction to separate alkanes and olefins from catalytic light gasoline is an effective method for maximizing the utility of gasoline fractions.This study presents the determination of liquid-liquid equilibrium data for the ternary system of 1-hexene-n-hexane-3-methylsulfolane at 30℃,40℃,and 50℃under atmospheric pressure.The obtained data facilitated the construction of a ternary phase diagram for the system.The results showed that the extraction selectivity of 1-hexene/n-hexane exceeded 1.5 when using 3-methylsulfolane as the extraction solvent.Furthermore,the thermodynamic consistency of the experimental data was examined using Hand’s equation and the Othmer-Tobias method.The correlation coefficient,R^(2)≥0.9578,indicated the acceptable reliability of the phase equilibrium data.Subsequently,the NRTL(non-random two liquid)model was used to correlate the liquid-liquid phase equilibrium data and derive the binary interaction parameter.Notably,the results demonstrated that the root mean square deviation of the NRTL model correlation values from the experimental values did not exceed 2.5%.展开更多
Synthetic biology efforts have also led to the development of photosynthetic cyanobacteria as"autotrophic cell factories"for biosynthesis of various biofuels directly from CO_(2).However,the low tolerance to...Synthetic biology efforts have also led to the development of photosynthetic cyanobacteria as"autotrophic cell factories"for biosynthesis of various biofuels directly from CO_(2).However,the low tolerance to toxicity of biofuels has restricted the economic application of cyanobacterial hosts.In this study,RNAseq transcriptomics was employed to reveal stress responses to exogenous n-hexane in Synechocystis sp.PCC 6803.Functional enrichment analysis of the transcriptomic data showed that signal transduction systems were induced significantly.To further identify regulatory genes related to n-hexane tolerance,a library of transcriptional regulators(TRs)deletion mutants was then screened for their roles in nhexane tolerance.The results showed that a knockout mutant of slr0724 that encodes an Hta R suppressor protein was more tolerant to n-hexane than the wild type,indicating the involvement of slr0724 in nhexane tolerance.This study provides the foundation for better understanding the cellular responses to n-hexane in Synechocystis sp.PCC 6803,which could contribute to the further engineering of nhexane tolerance in cyanobacteria.展开更多
Objective To investigate the toxic effects of n-hexane on the Ganod of female mice.Methods n-Hexane was administered to four groups of mice by inhalation at doses of 0,3.0,15.1,and 75.8 mL/m3 respectivelyfor five week...Objective To investigate the toxic effects of n-hexane on the Ganod of female mice.Methods n-Hexane was administered to four groups of mice by inhalation at doses of 0,3.0,15.1,and 75.8 mL/m3 respectivelyfor five weeks.Each group consisted of 10 mice,of which half were injected in first with 10 IU of pregnant mare serum gonadotrophin(PMSG) on the 33rd days,and then with 10 IU of human chorionic gonadotrophin(HCG) 48 hrs later.After the treatment,mouse sera were sampled and ovulating hormone(LH),follicle-stimulating hormone(FSH),estradiol(E2),and progesterone(P4) levels were measured by electrochemiluminescence immunoassays(ECLIA).In each group,the right ovaries of the non-super-ovulated mice were stained with hematoxylin and eosin while ovaries on the left side were prepared with the TUNEL method in order to detect apoptotic cells.Results The duration of the diestrus stage decreased significantly(P0.05) in the 75.8 mL/m3 group.All super-ovulated mice in each treatment group produced fewer eggs than those in the control group(P0.05).The number of follicles in ovaries in the 75.8 mL/m3 group was smaller compared with the control group(P0.05).The serum P4 levels in each treatment group were lower than those in the control group(F=6.196,P0.01).The cell apoptotic rate in the 75.8 mL/m3 group was higher(P0.05).Conclusion n-Hexane may have directly mediated via alterations hormone secretion and promoted granulosal cell apoptotic,which may be one of the important mechanisms for n-hexane induced mouse ovary impairment.展开更多
The photolysis of 16 polychlorinated biphenyls (PCBs) (including mono- through deca-chlorinated) in n-hexane was investigated under ultraviolet irradiation using a 500-W high-pressure mercury lamp. Photolysis of P...The photolysis of 16 polychlorinated biphenyls (PCBs) (including mono- through deca-chlorinated) in n-hexane was investigated under ultraviolet irradiation using a 500-W high-pressure mercury lamp. Photolysis of PCBs follows pseudo-first-order reaction kinetics, with photolysis rate constants ranging between 0.0011 s^-1 for PCB-52 and 0.0574 s^-1 for PCB-118. The degradation rates of PCBs by high-pressure mercury lamp irradiation were remarkably independent with respect to the degree of chlorination. Furthermore, partial least squares (PLS) models were developed to provide insight into which aspect of the molecular structure influenced PCB photolysis rate constants. It was found that the photolysis rates of PCBs increased with an increase in the net charge on the carbon atom (qc), (ELUMO-EHOMO)^2, and the Y-axis dipole moment (μy) values, or the decrease in the energy of the second highest occupied molecular orbital (EHOMO-1), energy of the lowest unoccupied molecular orbital (ELUMO), ELUMO + EHOMO, ELUMO - EHOMO, most positive atomic charge (q^+), and the twist angle of the chlorine atom (TA) values.展开更多
Aim: To study the toxic effect of n-hexane on sex hormone levels, including its effect on ovarian sex hormone secretion levels and the underlying mechanism. 1) In vivo experiment: The mice were exposed to n- hexane by...Aim: To study the toxic effect of n-hexane on sex hormone levels, including its effect on ovarian sex hormone secretion levels and the underlying mechanism. 1) In vivo experiment: The mice were exposed to n- hexane by static inhalation of doses of 0, 3.0, 15.1 or 75.8 ml/m3 once a day (4 hours), 7 days a week, for 5 consecutive weeks. After exposure, mouse sera were sampled to measure estradiol (E2) and progesterone (P4) levels by electrochemiluminescence immunoassays (ECLIA). 2) In vitro experiment: mice at different stages of the estrous cycle were sacrificed and their minced tissue pieces were incubated in medium containing hexane-2,5-dione (2,5-HD). Then, the E2 and P4 levels in the media were measured by ECLIA. In vivo assays, the serum P4 levels in each group were lower than the control group, which was statistically significant (F = 6.196, P 2 level of 75.8 mL/m3 dosage group was decreased (96.9522 ± 7.8652)) compared to the control group (119.1600 ± 25.6420), with statistical significance (P 4 levels of 15.1 mL/m3 and 75.8 mL/m3 dosage groups were also decreased (18.5938 ± 12.485pmol/L, 13.5550 ± 5.7789 pmol/L) and were statistically significantly (F = 6.196, P In vitro, the E2 levels at various stages of the estrous cycle were significantly different from the control groups (P In vitro, different concentrations of 2, 5-HD significantly inhibited the P4 level (P 4 levels at various stages of the estrous cycle were also significantly different from controls (P 0.05). The results indicate that n-hexane may inhibit release of ovarian E2 and P4, which may be the main reason for the interference of the reproductive endocrine system by n-hexane.展开更多
Platinum(Pt)supported on Zinc(Zn)modified silicalite-1(S-1)zeolite(denoted as Pt-Zn/S-1)was prepared by using a wetness-impregnation method and applied in the n-hexane aromatization reaction for the first time.Both Le...Platinum(Pt)supported on Zinc(Zn)modified silicalite-1(S-1)zeolite(denoted as Pt-Zn/S-1)was prepared by using a wetness-impregnation method and applied in the n-hexane aromatization reaction for the first time.Both Lewis and Bronsted acid sites were detected in Pt-Zn/S-1 catalyst by means of FT-IR adsorption of NH3 experiment,which were identified as mostly weak and medium ones.Besides,Pt and Zn species showed strong interaction,as revealed by the TPR(Temperature-programmed reduction)and XPS(X-ray photoelectron spectroscopy)experiments.Pt-Zn/S-1 catalyst exhibited excellent aromatization function rather than isomerization and cracking side reactions in the conversion of n-hexane.Pulse experimental study showed that 75.6%of n-hexane conversion and 76.8%of benzene selectivity were obtained over Pt0.1-Zn60/S-l catalyst at 550℃ and under atmospheric pressure.By spectroscopy tests and pulse experimental results,it was concluded that the n-hexane aromatization over Pt-Zn/S-1 catalyst follows a metal-acid bifunctional mechanism.Furthermore,with the assistance of Zn,the electron-deficient Pt species in Pt-Zn/S-1 showed good sulfur tolerance performance.展开更多
Objective This study was aimed to determine the effects of n-hexane on the maturation of mouse oocytes. Methods Cell culture was used to observe the maturation of mouse oocytes and CLSM was employed to determine their...Objective This study was aimed to determine the effects of n-hexane on the maturation of mouse oocytes. Methods Cell culture was used to observe the maturation of mouse oocytes and CLSM was employed to determine their apoptosis. Results Germinal vesicle breakdown (GVBD) and extrusion of the first polar body in mouse oocytes were significantly inhibited by n-hexane. After fertilization, the number of eggs in the mouse was significantly reduced by n-hexane. Mitochondrial membrane potentials (A^Um) were altered in mouse oocytes that were leading to apoptosis of the oocytes. Conclusion N-hexane might have affected the maturation of oocytes, causing alteration of ~qJm and leading to apoptosis which maybe one of the most imn(~rt^nt rnpch^ni^nn~展开更多
With the increasing attention to environmental protection,it is still necessary to strictly control the oil evaporation loss from the IFRT(internal floating-roof tank)to the atmosphere.Upon using n-hexane as a represe...With the increasing attention to environmental protection,it is still necessary to strictly control the oil evaporation loss from the IFRT(internal floating-roof tank)to the atmosphere.Upon using n-hexane as a representative of light oil,the effects of the WDAs(wind deviation angles)on airflow distribution,the wind speed,the n-hexane vapor concentration,and the evaporation loss rate in the IFRT were investigated,and the mass transfer of the vapor-air was analyzed.The results are shown as follows:when the WDA is 0°,the vapor concentration in the gas space above the floating deck is the lowest;when the WDA is 22.5°,the oil evaporation loss rate is the largest;when the WDA is 45°,the vapor concentration is the highest,but the evaporation loss rate is the smallest.It is recommended to arrange the vent to the wind direction with an angle of 45°to reduce the evaporation loss and protect the atmospheric environment.展开更多
The aim of this work was to evaluate the catalytic properties for n-hexane isomerization of bifunctional monometallic (Ni or Pt) and bimetallic catalysts (Pt-Ni), using HMOR zeolite as support. The method used for met...The aim of this work was to evaluate the catalytic properties for n-hexane isomerization of bifunctional monometallic (Ni or Pt) and bimetallic catalysts (Pt-Ni), using HMOR zeolite as support. The method used for metal dispersion in the zeolite was competitive ion exchange using ammine complexes [Ni(NH3)6]Cl2 and [Pt(NH3)4]Cl2 as precursors. The catalysts were characterized by X-Ray diffraction, X-Ray energy dispersion spectroscopy, temperature-programmed reduction and transmission electron microscopy. The n-hexane isomerization reaction using the catalysts was carried out to evaluate the catalyst activity. The reaction was carried out in a fixed bed reactor operating at 250?C, 1 atm, H2/C6 = 9 molar ratio. The profiles obtained from TPR suggest that, for bimetallic catalysts, the presence of platinum facilitates the reduction of Ni2+ cations. The bimetallic catalysts presented a higher activity in the isomerization of n-hexane when compared to the monometallic ones, as well better stability as the Pt content in the solid increases.展开更多
Objective:To investigate the antipyretic and anticonvulsant activities of n-hexane fraction of Viola betonicifolia(V.betonicifolia).Methods:The antipyretic effect was scrutinized using brewer's yeast induced pyrex...Objective:To investigate the antipyretic and anticonvulsant activities of n-hexane fraction of Viola betonicifolia(V.betonicifolia).Methods:The antipyretic effect was scrutinized using brewer's yeast induced pyrexia and anticonvlsion effect was tested using pentylenetetrazol and strychnine induced convulsion in mice.Results:N-hexane fraction of V.betonicifolia demonstrated highly significant antipyretic activity during various assessment times(1-5 h)when challenged in yeast induced pyrexia test.The effect was in a dose dependent manner with maximum attenuation(82.50%)observed at 300 mg/kg i.p.When tested in pentylenetetrazol induced convulsion test,the 1st stage(Ear and facial twitching)and 2nd stage(Convulsive wave through the body)was 100%protected during 24 h at all the test doses(300,400 and 500 mg/kg i.p.),while the latency time of remaining stages was significantly increased.The maximum effect was observed by n-hexane fraction of V.betonicifolia at 400 and 500 mg/kg i.p.,as the latency time for generalized clonic-tonic seizure(5th stage)was increased up to 25.34 min.However,n-hexane fraction of V.betonicifolia had no protection in strychnine induced convulsion test.Conclusions:In conclusion,phytopharmacological studies provide scientific foundation to the folk uses of the plant in the treatment of pyrexia and neurological disorders.展开更多
Xe-129-NMR and TEM were used to study the location and dispersion of Pt particles in KL zeolite with lanthanum incorporation. Owing to the interaction between Pt and La, more Pt particles accompanying La3+ were locate...Xe-129-NMR and TEM were used to study the location and dispersion of Pt particles in KL zeolite with lanthanum incorporation. Owing to the interaction between Pt and La, more Pt particles accompanying La3+ were located in the inner channels of KL zeolite, rather than agglomerated in the external surface. The dispersion of Pt particles was therefore improved. Pt/KL zeolite modified by La showed a little lower reactivity for aromatization of n-hexane, but much higher resistance to sulfur-poisoning because of the existence of new acidic sites.展开更多
Loranthus micranthus is the species of mistletoe peculiar to the eastern province of Nigeria.It has been shown to possess anti-diabetic,anumotility,antimicrobial and antihypertensive activities which are host-tree dep...Loranthus micranthus is the species of mistletoe peculiar to the eastern province of Nigeria.It has been shown to possess anti-diabetic,anumotility,antimicrobial and antihypertensive activities which are host-tree dependent. The antimicrobial activity was found to vary with the season during which the plant was harvested.We are of the opinion that this species should possess immunomodulating potentials as have been reported for the European species,Viscum album.In our efforts to establish the bio-activities and active principles in our local mistletoe, the immunomodulatory activity of n-hexane and methanol extracts from Loranthus micranthus parasitic on Persea americana was assessed at three dose levels ranging from 100 to 400 mg/kg body weight using delayed type hypersensitivity reaction(DTHR) and cyclophosphamide-induced myelosuppression models in mice.This was compared with responses from a standard immunostimulatory drug,levamisole.Preliminary phytochemical analysis of the plant showed the presence of tannins,flavonoids,alkaloids,terpenoids,carbohydrates and saponins.Regression analysis indicated a dose-dependent response relationship in the parameters measured with over 170%increase for both extracts at the highest dose level.The one way ANOVA test showed significant variation in the parameters between the controls and the different dose levels.However,at 95%confidence level,(P【0.05),there was no statistically significant difference between the two extracts, an indication that the active immunomodulant(s) could be both in the polar and non-polar crude extract.In conclusion,the present results have established some immune stimulating actions of the Eastern Nigeria mistletoe, Loranthus micranthus thus indicating that this variant of the semi parasitic plant holds a strong promise as an immunostimulatory candidate.There is therefore,a basis for further detailed investigation on the fractions and specific constituents.Thus,these extracts from Loranthus micranthus possess pronounced immune stimulating action comparable to Levamisole in mouse-based models.展开更多
A novel ZIF-8-CMC hybrid material was fabricated from the hybridization of ZIF-8 and carboxymethylcellulose(CMC) by impregnation method for n-hexane/3-methylpentane separation.The surface properties of ZIF-8 were tail...A novel ZIF-8-CMC hybrid material was fabricated from the hybridization of ZIF-8 and carboxymethylcellulose(CMC) by impregnation method for n-hexane/3-methylpentane separation.The surface properties of ZIF-8 were tailored by introducing CMC into ZIF-8 nanoparticles.In this work,adsorption separation of n-hexane(nHEX) and 3-methylpentane(3 MP) on ZIF-8-CMC were investigated by batch vapor-phase adsorption and liquid-phase breakthrough adsorption.The adsorption selectivity of nHEX/3 MP reversed from preferable adsorption of nHEX to preferable adsorption of 3 MP upon the increasing of CMC containing in the hybrid materials.As the temperature increases,the adsorption amounts of nHEX and 3 MP decrease.With the increasing of CMC contents,the nHEX uptake decreased,the uptake capacity of 3 MP increased gradually.For liquid-phase breakthrough adsorption,the dynamic adsorption capacity of nHEX also decreased with the increasing of temperature.展开更多
The biofiltration of n-hexane is studied to optimize determinants factors of hydrophobic VOC filtration efficiency. Four trickle-bed air biofilters (TBABs) were employed;two of which were supplied with nutrients buffe...The biofiltration of n-hexane is studied to optimize determinants factors of hydrophobic VOC filtration efficiency. Four trickle-bed air biofilters (TBABs) were employed;two of which were supplied with nutrients buffered at a neutral pH, while another two at an acidic pH of 4 to induce and enhance fungal growth. The loading rate of n-hexane was kept constant in all TBABs at 13 g/m3/h. At each pH levels studied, the biomass of the TBABs was pre-acclimated using different ratios of n-hexane and methanol. The fungal biomass responsible for the degradation of n-hexane was then examined and quantified. Dichloran Rose Bengal Chloramphenicol agar was used for fungi quantification, and optical microscopy for classification. Effluent biomass was validated by measuring volatile suspended solids. Fungal counts resulting from n-hexane biodegradation were related to nitrate and carbon consumption. It was found that n-hexane elimination capacity closely followed biomass growth, and reached a steady-state at an optimum biomass density of roughly 3000 cfu/ml. Major shifts in fungal species were observed in all TBABs. Dominant fungal species grew slowly to become the most numerous, and were found to provide maximum elimination capacity, although TBABs pre-acclimated to higher methanol concentrations took less time to reach this steady-state. It was concluded, therefore, that steady and monitored growth of TBAB biomass is an essential factor in maximizing fungi’s ability to metabolize VOCs and that a new ecological biofiltration model may be the most effective at VOC purification.展开更多
This project is funded by the China government to develop the industrialization process of pesticide residue grade n-hexane, in which the industrial n-Hexane is used as crude purified by decoloration, distillation and...This project is funded by the China government to develop the industrialization process of pesticide residue grade n-hexane, in which the industrial n-Hexane is used as crude purified by decoloration, distillation and filtration process. The products are validated by National Research Center for Environmental Analysis and Measurement (CNEAC), National Research Center for Geoanalysis, Chinese Academy of Inspection and Quarantine (CAIQ), Chinese Academy of Agricultural Sciences (CAAS) and other government originations for polychlorinated biphenyls, organochlorine pesticide or chiral pesticides analysis and further confirmed that it’s competitive to all others imported n-Hexane currently occupied in China. This patented technique will meet pesticide residue grade n-Hexane market in China and seek for cooperation globally.展开更多
The catalytic dehydrocyclization of n-hexane was studied here for the first time using a number of compounds based on H3PMo12O40. The described catalysts were prepared by either replacing the acidic proton with counte...The catalytic dehydrocyclization of n-hexane was studied here for the first time using a number of compounds based on H3PMo12O40. The described catalysts were prepared by either replacing the acidic proton with counter-ions such as ammonium or transition metal cations (NH4+, Fe3+, K+), or by replacing Mo6+ with (Ni3+, Co3+, Mn3+) in the polyoxometalate framework, as reported earlier. For comparison purposes, the known (TBA)7PW11O39 catalyst system was used. All reactions were conducted at different temperatures in the range 200 - 450. The Keggin structure of these heteropolycompounds was ascertained by XRD, UV and IR measurements. 31P NMR measurements and thermal behaviour of the prepared catalysts were also studied. These modified polyoxometalates exhibited heterogeneous superacidic catalytic activities in dehydrocyclization of n-hexane into benzene, cyclohexane, cyclohexene and cyclohexadiene. The catalysts obtained by substituting the acidic proton or coordination atom exhibited higher selectivity and stability than the parent compound H3PMo12O40. Catalytic activity and selectivity were heavily dependent on the composition of the catalyst and on the reaction conditions. At higher temperatures, the catalyst exhibited higher conversion efficiency at the expense of selectivity. Using higher temperatures (>400) in the presence of hydrogen carrier gas, selectivity towards dehydrocyclization ceased and methane dominated. To explain the results, a plausible mechanism is presented, based on super-acidic nature of the catalyst systems.展开更多
Antibacterial activity of methanol, n-hexane and water extracts of seeds and bark of Moringa oleifera and Moringa ovalifolia was conducted. The causative agents of common bacterial infections that are thought to cause...Antibacterial activity of methanol, n-hexane and water extracts of seeds and bark of Moringa oleifera and Moringa ovalifolia was conducted. The causative agents of common bacterial infections that are thought to cause water-borne diseases, namely, Escherichia coli, Enterococcus faecalis, and Bacillus cereus were chosen for the study. The paper-disc diffusion method was used with treatments arranged in a completely randomized design and replicated four times. The M. oleifera extracts showed more inhibitory effect than those of M. ovolifolia. The conventional antibiotic Ampicilin generally showed higher inhibitory effect than the extracts of both M. oleifera and M. ovalifolia. The inhibitory effect varied depending on the solvent used. The n-hexane extracts of both seeds and bark of M. ovalifolia and M. oleifera had almost the same inhibition activities (6 ± 1 mm mean inhibition zones) on B. cereus, E. coli and E. faecalis. The n-hexane extract generally gave lower antibacterial activities than those of the other solvents for seeds and back. The results of the study showed that M. oleifera and M. ovalifolia had a degree of antibacterial properties against the selected test organisms that cause water borne diseases.展开更多
The chemical composition of n-hexane extractives from lignocellulose residual contained in different agroindustrial wastes was studied. The n-hexane extract, which accounted for 1.6% of total lignocellulose residual w...The chemical composition of n-hexane extractives from lignocellulose residual contained in different agroindustrial wastes was studied. The n-hexane extract, which accounted for 1.6% of total lignocellulose residual weight, was analysed by 1H-NMR and gas chromatography/mass spectrometry. The most predominant compounds identified were aliphatic hydrocarbons (lineal alkanes, branched alkanes, alkenes). Additionally, terpenes, ketones, fatty alcohols, fatty acids and steroids were also found together in minor amounts. The lipophilic compounds in n-hexane extracts in three lignocellulosic wastes, which is highly valuable information for a more complete industrial utilization of these lignocellulosic materials.展开更多
Background Chronic exposure to n-hexane can lead to peripheral neuropathy that no effective treatment regimen could be applied presently. This study investigated whether myelin protein zero (P0) protein and its anti...Background Chronic exposure to n-hexane can lead to peripheral neuropathy that no effective treatment regimen could be applied presently. This study investigated whether myelin protein zero (P0) protein and its antibody could be used to distinguish n-hexane intoxication and protect workers from peripheral neuropathy. Methods We compared P0 protein and its antibody among three levels of n-hexane-exposed groups, which included 18 patients with n-hexane-induced peripheral neuropathy as case group, 120 n-hexane-exposed workers as n-hexane- exposed control group, and 147 non-hexane-exposed participants used as control group. ELISA method was applied to detect P0 protein and its antibody. Results P0 protein in serum was significantly higher in the case group and n-hexane-exposed control group in comparison with the control group (P〈0.01). Compared with the n-hexane-exposed control group, the case group also had significant increase of P0 protein (P〈0.01). After 6 months therapy, P0 protein was observed to decrease significantly in the case group (P〈0.01). The P0 antibody in serum was significantly higher in the n-hexane-exposed control group than in the control group (P〈0.01), but not significantly different between cases and controls. Conclusions P0 antibodies in serum may be a short-term effect biomarker for n-hexane exposure. P0 protein in serum may be an early effective biomarker for peripheral nerve neuropathy and its biological limit value needs investigation in the future study.展开更多
In this work,we used the in ert substances silic one oil a nd n-hexane to modulate the solve nt environ ment,and in so doing tailor the preparation of magnesium ethoxide(Mg(0Et)2)particles.We found the following:(1)no...In this work,we used the in ert substances silic one oil a nd n-hexane to modulate the solve nt environ ment,and in so doing tailor the preparation of magnesium ethoxide(Mg(0Et)2)particles.We found the following:(1)non polar n-hexane mainly modulates the polarity of the solvent to control the precipitation rate and size of the Mg(OEt)2 seeds,thereby triggering accelerated nucleation to form small primary particles;and(2)silicone oil(relatively high polarity and viscosity)facilitates the growth and agglomeration stage,to improve inter-particle dispersion and obtain relatively uniform Mg(OEt)2 particles.We summarized these findings in a comm on mechanism for preparing Mg(OEt)2 particles with uniform morphology,small size,and high bulk density as per the synergistic effect of n-hexane and silicone oil.The ratios of silicone oil end n-hexane are flexible,and afford various regular and well-dispersed Mg(OEt)2 particles that are 5-30μm in size and 0.2-0.7 g/cm^3 in bulk density.The nanoparticles thus have the potential to serve in diverse applications such as catalysis.展开更多
基金The authors wish to acknowledge financial support by the project of SINOPEC(No.223039).
文摘Utilizing solvent extraction to separate alkanes and olefins from catalytic light gasoline is an effective method for maximizing the utility of gasoline fractions.This study presents the determination of liquid-liquid equilibrium data for the ternary system of 1-hexene-n-hexane-3-methylsulfolane at 30℃,40℃,and 50℃under atmospheric pressure.The obtained data facilitated the construction of a ternary phase diagram for the system.The results showed that the extraction selectivity of 1-hexene/n-hexane exceeded 1.5 when using 3-methylsulfolane as the extraction solvent.Furthermore,the thermodynamic consistency of the experimental data was examined using Hand’s equation and the Othmer-Tobias method.The correlation coefficient,R^(2)≥0.9578,indicated the acceptable reliability of the phase equilibrium data.Subsequently,the NRTL(non-random two liquid)model was used to correlate the liquid-liquid phase equilibrium data and derive the binary interaction parameter.Notably,the results demonstrated that the root mean square deviation of the NRTL model correlation values from the experimental values did not exceed 2.5%.
基金supported by grants from the National Key Research and Development Program of China(2020YFA0906800,2021YFA0909700,2018YFA0903600 and 2019YFA0904600)。
文摘Synthetic biology efforts have also led to the development of photosynthetic cyanobacteria as"autotrophic cell factories"for biosynthesis of various biofuels directly from CO_(2).However,the low tolerance to toxicity of biofuels has restricted the economic application of cyanobacterial hosts.In this study,RNAseq transcriptomics was employed to reveal stress responses to exogenous n-hexane in Synechocystis sp.PCC 6803.Functional enrichment analysis of the transcriptomic data showed that signal transduction systems were induced significantly.To further identify regulatory genes related to n-hexane tolerance,a library of transcriptional regulators(TRs)deletion mutants was then screened for their roles in nhexane tolerance.The results showed that a knockout mutant of slr0724 that encodes an Hta R suppressor protein was more tolerant to n-hexane than the wild type,indicating the involvement of slr0724 in nhexane tolerance.This study provides the foundation for better understanding the cellular responses to n-hexane in Synechocystis sp.PCC 6803,which could contribute to the further engineering of nhexane tolerance in cyanobacteria.
基金supported by the Research Fund from National Nature Science Foundation of China,30972514
文摘Objective To investigate the toxic effects of n-hexane on the Ganod of female mice.Methods n-Hexane was administered to four groups of mice by inhalation at doses of 0,3.0,15.1,and 75.8 mL/m3 respectivelyfor five weeks.Each group consisted of 10 mice,of which half were injected in first with 10 IU of pregnant mare serum gonadotrophin(PMSG) on the 33rd days,and then with 10 IU of human chorionic gonadotrophin(HCG) 48 hrs later.After the treatment,mouse sera were sampled and ovulating hormone(LH),follicle-stimulating hormone(FSH),estradiol(E2),and progesterone(P4) levels were measured by electrochemiluminescence immunoassays(ECLIA).In each group,the right ovaries of the non-super-ovulated mice were stained with hematoxylin and eosin while ovaries on the left side were prepared with the TUNEL method in order to detect apoptotic cells.Results The duration of the diestrus stage decreased significantly(P0.05) in the 75.8 mL/m3 group.All super-ovulated mice in each treatment group produced fewer eggs than those in the control group(P0.05).The number of follicles in ovaries in the 75.8 mL/m3 group was smaller compared with the control group(P0.05).The serum P4 levels in each treatment group were lower than those in the control group(F=6.196,P0.01).The cell apoptotic rate in the 75.8 mL/m3 group was higher(P0.05).Conclusion n-Hexane may have directly mediated via alterations hormone secretion and promoted granulosal cell apoptotic,which may be one of the important mechanisms for n-hexane induced mouse ovary impairment.
基金This work was supported by the National Natural Science Foundation of China(No.20507010)the Excellent Young Scientist Fund of China(No.50625823).
文摘The photolysis of 16 polychlorinated biphenyls (PCBs) (including mono- through deca-chlorinated) in n-hexane was investigated under ultraviolet irradiation using a 500-W high-pressure mercury lamp. Photolysis of PCBs follows pseudo-first-order reaction kinetics, with photolysis rate constants ranging between 0.0011 s^-1 for PCB-52 and 0.0574 s^-1 for PCB-118. The degradation rates of PCBs by high-pressure mercury lamp irradiation were remarkably independent with respect to the degree of chlorination. Furthermore, partial least squares (PLS) models were developed to provide insight into which aspect of the molecular structure influenced PCB photolysis rate constants. It was found that the photolysis rates of PCBs increased with an increase in the net charge on the carbon atom (qc), (ELUMO-EHOMO)^2, and the Y-axis dipole moment (μy) values, or the decrease in the energy of the second highest occupied molecular orbital (EHOMO-1), energy of the lowest unoccupied molecular orbital (ELUMO), ELUMO + EHOMO, ELUMO - EHOMO, most positive atomic charge (q^+), and the twist angle of the chlorine atom (TA) values.
文摘Aim: To study the toxic effect of n-hexane on sex hormone levels, including its effect on ovarian sex hormone secretion levels and the underlying mechanism. 1) In vivo experiment: The mice were exposed to n- hexane by static inhalation of doses of 0, 3.0, 15.1 or 75.8 ml/m3 once a day (4 hours), 7 days a week, for 5 consecutive weeks. After exposure, mouse sera were sampled to measure estradiol (E2) and progesterone (P4) levels by electrochemiluminescence immunoassays (ECLIA). 2) In vitro experiment: mice at different stages of the estrous cycle were sacrificed and their minced tissue pieces were incubated in medium containing hexane-2,5-dione (2,5-HD). Then, the E2 and P4 levels in the media were measured by ECLIA. In vivo assays, the serum P4 levels in each group were lower than the control group, which was statistically significant (F = 6.196, P 2 level of 75.8 mL/m3 dosage group was decreased (96.9522 ± 7.8652)) compared to the control group (119.1600 ± 25.6420), with statistical significance (P 4 levels of 15.1 mL/m3 and 75.8 mL/m3 dosage groups were also decreased (18.5938 ± 12.485pmol/L, 13.5550 ± 5.7789 pmol/L) and were statistically significantly (F = 6.196, P In vitro, the E2 levels at various stages of the estrous cycle were significantly different from the control groups (P In vitro, different concentrations of 2, 5-HD significantly inhibited the P4 level (P 4 levels at various stages of the estrous cycle were also significantly different from controls (P 0.05). The results indicate that n-hexane may inhibit release of ovarian E2 and P4, which may be the main reason for the interference of the reproductive endocrine system by n-hexane.
基金financially supported by the National Natural Science Foundation of China (21603023)
文摘Platinum(Pt)supported on Zinc(Zn)modified silicalite-1(S-1)zeolite(denoted as Pt-Zn/S-1)was prepared by using a wetness-impregnation method and applied in the n-hexane aromatization reaction for the first time.Both Lewis and Bronsted acid sites were detected in Pt-Zn/S-1 catalyst by means of FT-IR adsorption of NH3 experiment,which were identified as mostly weak and medium ones.Besides,Pt and Zn species showed strong interaction,as revealed by the TPR(Temperature-programmed reduction)and XPS(X-ray photoelectron spectroscopy)experiments.Pt-Zn/S-1 catalyst exhibited excellent aromatization function rather than isomerization and cracking side reactions in the conversion of n-hexane.Pulse experimental study showed that 75.6%of n-hexane conversion and 76.8%of benzene selectivity were obtained over Pt0.1-Zn60/S-l catalyst at 550℃ and under atmospheric pressure.By spectroscopy tests and pulse experimental results,it was concluded that the n-hexane aromatization over Pt-Zn/S-1 catalyst follows a metal-acid bifunctional mechanism.Furthermore,with the assistance of Zn,the electron-deficient Pt species in Pt-Zn/S-1 showed good sulfur tolerance performance.
基金supported by the National Nature Science Foundation of China,30972514
文摘Objective This study was aimed to determine the effects of n-hexane on the maturation of mouse oocytes. Methods Cell culture was used to observe the maturation of mouse oocytes and CLSM was employed to determine their apoptosis. Results Germinal vesicle breakdown (GVBD) and extrusion of the first polar body in mouse oocytes were significantly inhibited by n-hexane. After fertilization, the number of eggs in the mouse was significantly reduced by n-hexane. Mitochondrial membrane potentials (A^Um) were altered in mouse oocytes that were leading to apoptosis of the oocytes. Conclusion N-hexane might have affected the maturation of oocytes, causing alteration of ~qJm and leading to apoptosis which maybe one of the most imn(~rt^nt rnpch^ni^nn~
基金the National Natural Science Foundation of China(No.51574044)the Key Research and Development Program of Jiangsu Province(Industry Foresight and Common Key Technology)(No.BE2018065)+1 种基金the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX182630)the Nature Science Foundation of Jiangsu Province(No.BK20150269)。
文摘With the increasing attention to environmental protection,it is still necessary to strictly control the oil evaporation loss from the IFRT(internal floating-roof tank)to the atmosphere.Upon using n-hexane as a representative of light oil,the effects of the WDAs(wind deviation angles)on airflow distribution,the wind speed,the n-hexane vapor concentration,and the evaporation loss rate in the IFRT were investigated,and the mass transfer of the vapor-air was analyzed.The results are shown as follows:when the WDA is 0°,the vapor concentration in the gas space above the floating deck is the lowest;when the WDA is 22.5°,the oil evaporation loss rate is the largest;when the WDA is 45°,the vapor concentration is the highest,but the evaporation loss rate is the smallest.It is recommended to arrange the vent to the wind direction with an angle of 45°to reduce the evaporation loss and protect the atmospheric environment.
基金the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico(CNPq.Brazil)and Petrobras for their financial support to this research.
文摘The aim of this work was to evaluate the catalytic properties for n-hexane isomerization of bifunctional monometallic (Ni or Pt) and bimetallic catalysts (Pt-Ni), using HMOR zeolite as support. The method used for metal dispersion in the zeolite was competitive ion exchange using ammine complexes [Ni(NH3)6]Cl2 and [Pt(NH3)4]Cl2 as precursors. The catalysts were characterized by X-Ray diffraction, X-Ray energy dispersion spectroscopy, temperature-programmed reduction and transmission electron microscopy. The n-hexane isomerization reaction using the catalysts was carried out to evaluate the catalyst activity. The reaction was carried out in a fixed bed reactor operating at 250?C, 1 atm, H2/C6 = 9 molar ratio. The profiles obtained from TPR suggest that, for bimetallic catalysts, the presence of platinum facilitates the reduction of Ni2+ cations. The bimetallic catalysts presented a higher activity in the isomerization of n-hexane when compared to the monometallic ones, as well better stability as the Pt content in the solid increases.
基金Financially Supported by Higher Education Commission (HEC) Pakistan (Grant No.bm6-071/hec/pak.)
文摘Objective:To investigate the antipyretic and anticonvulsant activities of n-hexane fraction of Viola betonicifolia(V.betonicifolia).Methods:The antipyretic effect was scrutinized using brewer's yeast induced pyrexia and anticonvlsion effect was tested using pentylenetetrazol and strychnine induced convulsion in mice.Results:N-hexane fraction of V.betonicifolia demonstrated highly significant antipyretic activity during various assessment times(1-5 h)when challenged in yeast induced pyrexia test.The effect was in a dose dependent manner with maximum attenuation(82.50%)observed at 300 mg/kg i.p.When tested in pentylenetetrazol induced convulsion test,the 1st stage(Ear and facial twitching)and 2nd stage(Convulsive wave through the body)was 100%protected during 24 h at all the test doses(300,400 and 500 mg/kg i.p.),while the latency time of remaining stages was significantly increased.The maximum effect was observed by n-hexane fraction of V.betonicifolia at 400 and 500 mg/kg i.p.,as the latency time for generalized clonic-tonic seizure(5th stage)was increased up to 25.34 min.However,n-hexane fraction of V.betonicifolia had no protection in strychnine induced convulsion test.Conclusions:In conclusion,phytopharmacological studies provide scientific foundation to the folk uses of the plant in the treatment of pyrexia and neurological disorders.
文摘Xe-129-NMR and TEM were used to study the location and dispersion of Pt particles in KL zeolite with lanthanum incorporation. Owing to the interaction between Pt and La, more Pt particles accompanying La3+ were located in the inner channels of KL zeolite, rather than agglomerated in the external surface. The dispersion of Pt particles was therefore improved. Pt/KL zeolite modified by La showed a little lower reactivity for aromatization of n-hexane, but much higher resistance to sulfur-poisoning because of the existence of new acidic sites.
文摘Loranthus micranthus is the species of mistletoe peculiar to the eastern province of Nigeria.It has been shown to possess anti-diabetic,anumotility,antimicrobial and antihypertensive activities which are host-tree dependent. The antimicrobial activity was found to vary with the season during which the plant was harvested.We are of the opinion that this species should possess immunomodulating potentials as have been reported for the European species,Viscum album.In our efforts to establish the bio-activities and active principles in our local mistletoe, the immunomodulatory activity of n-hexane and methanol extracts from Loranthus micranthus parasitic on Persea americana was assessed at three dose levels ranging from 100 to 400 mg/kg body weight using delayed type hypersensitivity reaction(DTHR) and cyclophosphamide-induced myelosuppression models in mice.This was compared with responses from a standard immunostimulatory drug,levamisole.Preliminary phytochemical analysis of the plant showed the presence of tannins,flavonoids,alkaloids,terpenoids,carbohydrates and saponins.Regression analysis indicated a dose-dependent response relationship in the parameters measured with over 170%increase for both extracts at the highest dose level.The one way ANOVA test showed significant variation in the parameters between the controls and the different dose levels.However,at 95%confidence level,(P【0.05),there was no statistically significant difference between the two extracts, an indication that the active immunomodulant(s) could be both in the polar and non-polar crude extract.In conclusion,the present results have established some immune stimulating actions of the Eastern Nigeria mistletoe, Loranthus micranthus thus indicating that this variant of the semi parasitic plant holds a strong promise as an immunostimulatory candidate.There is therefore,a basis for further detailed investigation on the fractions and specific constituents.Thus,these extracts from Loranthus micranthus possess pronounced immune stimulating action comparable to Levamisole in mouse-based models.
基金supported by the National Natural Science Foundation of China (Nos. 11775037 and 21676030)the Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology (BM212110)The Postgraduate Innovation Project of Changzhou University (KYCX19_1782)。
文摘A novel ZIF-8-CMC hybrid material was fabricated from the hybridization of ZIF-8 and carboxymethylcellulose(CMC) by impregnation method for n-hexane/3-methylpentane separation.The surface properties of ZIF-8 were tailored by introducing CMC into ZIF-8 nanoparticles.In this work,adsorption separation of n-hexane(nHEX) and 3-methylpentane(3 MP) on ZIF-8-CMC were investigated by batch vapor-phase adsorption and liquid-phase breakthrough adsorption.The adsorption selectivity of nHEX/3 MP reversed from preferable adsorption of nHEX to preferable adsorption of 3 MP upon the increasing of CMC containing in the hybrid materials.As the temperature increases,the adsorption amounts of nHEX and 3 MP decrease.With the increasing of CMC contents,the nHEX uptake decreased,the uptake capacity of 3 MP increased gradually.For liquid-phase breakthrough adsorption,the dynamic adsorption capacity of nHEX also decreased with the increasing of temperature.
文摘The biofiltration of n-hexane is studied to optimize determinants factors of hydrophobic VOC filtration efficiency. Four trickle-bed air biofilters (TBABs) were employed;two of which were supplied with nutrients buffered at a neutral pH, while another two at an acidic pH of 4 to induce and enhance fungal growth. The loading rate of n-hexane was kept constant in all TBABs at 13 g/m3/h. At each pH levels studied, the biomass of the TBABs was pre-acclimated using different ratios of n-hexane and methanol. The fungal biomass responsible for the degradation of n-hexane was then examined and quantified. Dichloran Rose Bengal Chloramphenicol agar was used for fungi quantification, and optical microscopy for classification. Effluent biomass was validated by measuring volatile suspended solids. Fungal counts resulting from n-hexane biodegradation were related to nitrate and carbon consumption. It was found that n-hexane elimination capacity closely followed biomass growth, and reached a steady-state at an optimum biomass density of roughly 3000 cfu/ml. Major shifts in fungal species were observed in all TBABs. Dominant fungal species grew slowly to become the most numerous, and were found to provide maximum elimination capacity, although TBABs pre-acclimated to higher methanol concentrations took less time to reach this steady-state. It was concluded, therefore, that steady and monitored growth of TBAB biomass is an essential factor in maximizing fungi’s ability to metabolize VOCs and that a new ecological biofiltration model may be the most effective at VOC purification.
文摘This project is funded by the China government to develop the industrialization process of pesticide residue grade n-hexane, in which the industrial n-Hexane is used as crude purified by decoloration, distillation and filtration process. The products are validated by National Research Center for Environmental Analysis and Measurement (CNEAC), National Research Center for Geoanalysis, Chinese Academy of Inspection and Quarantine (CAIQ), Chinese Academy of Agricultural Sciences (CAAS) and other government originations for polychlorinated biphenyls, organochlorine pesticide or chiral pesticides analysis and further confirmed that it’s competitive to all others imported n-Hexane currently occupied in China. This patented technique will meet pesticide residue grade n-Hexane market in China and seek for cooperation globally.
文摘The catalytic dehydrocyclization of n-hexane was studied here for the first time using a number of compounds based on H3PMo12O40. The described catalysts were prepared by either replacing the acidic proton with counter-ions such as ammonium or transition metal cations (NH4+, Fe3+, K+), or by replacing Mo6+ with (Ni3+, Co3+, Mn3+) in the polyoxometalate framework, as reported earlier. For comparison purposes, the known (TBA)7PW11O39 catalyst system was used. All reactions were conducted at different temperatures in the range 200 - 450. The Keggin structure of these heteropolycompounds was ascertained by XRD, UV and IR measurements. 31P NMR measurements and thermal behaviour of the prepared catalysts were also studied. These modified polyoxometalates exhibited heterogeneous superacidic catalytic activities in dehydrocyclization of n-hexane into benzene, cyclohexane, cyclohexene and cyclohexadiene. The catalysts obtained by substituting the acidic proton or coordination atom exhibited higher selectivity and stability than the parent compound H3PMo12O40. Catalytic activity and selectivity were heavily dependent on the composition of the catalyst and on the reaction conditions. At higher temperatures, the catalyst exhibited higher conversion efficiency at the expense of selectivity. Using higher temperatures (>400) in the presence of hydrogen carrier gas, selectivity towards dehydrocyclization ceased and methane dominated. To explain the results, a plausible mechanism is presented, based on super-acidic nature of the catalyst systems.
文摘Antibacterial activity of methanol, n-hexane and water extracts of seeds and bark of Moringa oleifera and Moringa ovalifolia was conducted. The causative agents of common bacterial infections that are thought to cause water-borne diseases, namely, Escherichia coli, Enterococcus faecalis, and Bacillus cereus were chosen for the study. The paper-disc diffusion method was used with treatments arranged in a completely randomized design and replicated four times. The M. oleifera extracts showed more inhibitory effect than those of M. ovolifolia. The conventional antibiotic Ampicilin generally showed higher inhibitory effect than the extracts of both M. oleifera and M. ovalifolia. The inhibitory effect varied depending on the solvent used. The n-hexane extracts of both seeds and bark of M. ovalifolia and M. oleifera had almost the same inhibition activities (6 ± 1 mm mean inhibition zones) on B. cereus, E. coli and E. faecalis. The n-hexane extract generally gave lower antibacterial activities than those of the other solvents for seeds and back. The results of the study showed that M. oleifera and M. ovalifolia had a degree of antibacterial properties against the selected test organisms that cause water borne diseases.
基金To the National Council of Science and Technology(Conacyt)for the financing of the project.
文摘The chemical composition of n-hexane extractives from lignocellulose residual contained in different agroindustrial wastes was studied. The n-hexane extract, which accounted for 1.6% of total lignocellulose residual weight, was analysed by 1H-NMR and gas chromatography/mass spectrometry. The most predominant compounds identified were aliphatic hydrocarbons (lineal alkanes, branched alkanes, alkenes). Additionally, terpenes, ketones, fatty alcohols, fatty acids and steroids were also found together in minor amounts. The lipophilic compounds in n-hexane extracts in three lignocellulosic wastes, which is highly valuable information for a more complete industrial utilization of these lignocellulosic materials.
文摘Background Chronic exposure to n-hexane can lead to peripheral neuropathy that no effective treatment regimen could be applied presently. This study investigated whether myelin protein zero (P0) protein and its antibody could be used to distinguish n-hexane intoxication and protect workers from peripheral neuropathy. Methods We compared P0 protein and its antibody among three levels of n-hexane-exposed groups, which included 18 patients with n-hexane-induced peripheral neuropathy as case group, 120 n-hexane-exposed workers as n-hexane- exposed control group, and 147 non-hexane-exposed participants used as control group. ELISA method was applied to detect P0 protein and its antibody. Results P0 protein in serum was significantly higher in the case group and n-hexane-exposed control group in comparison with the control group (P〈0.01). Compared with the n-hexane-exposed control group, the case group also had significant increase of P0 protein (P〈0.01). After 6 months therapy, P0 protein was observed to decrease significantly in the case group (P〈0.01). The P0 antibody in serum was significantly higher in the n-hexane-exposed control group than in the control group (P〈0.01), but not significantly different between cases and controls. Conclusions P0 antibodies in serum may be a short-term effect biomarker for n-hexane exposure. P0 protein in serum may be an early effective biomarker for peripheral nerve neuropathy and its biological limit value needs investigation in the future study.
基金the National Natural Science Foundation of China(grant numbers 21422603,U1662120,and 21978152).
文摘In this work,we used the in ert substances silic one oil a nd n-hexane to modulate the solve nt environ ment,and in so doing tailor the preparation of magnesium ethoxide(Mg(0Et)2)particles.We found the following:(1)non polar n-hexane mainly modulates the polarity of the solvent to control the precipitation rate and size of the Mg(OEt)2 seeds,thereby triggering accelerated nucleation to form small primary particles;and(2)silicone oil(relatively high polarity and viscosity)facilitates the growth and agglomeration stage,to improve inter-particle dispersion and obtain relatively uniform Mg(OEt)2 particles.We summarized these findings in a comm on mechanism for preparing Mg(OEt)2 particles with uniform morphology,small size,and high bulk density as per the synergistic effect of n-hexane and silicone oil.The ratios of silicone oil end n-hexane are flexible,and afford various regular and well-dispersed Mg(OEt)2 particles that are 5-30μm in size and 0.2-0.7 g/cm^3 in bulk density.The nanoparticles thus have the potential to serve in diverse applications such as catalysis.