Root border cells, previously referred to as sloughed root cap cells, is a special cell population which separates in large numbers from the periphery of the root cap and accumulates in the root tip. Recent evidence r...Root border cells, previously referred to as sloughed root cap cells, is a special cell population which separates in large numbers from the periphery of the root cap and accumulates in the root tip. Recent evidence reveals that border cells, whose development is regulated by endogenous and exogenous signals, are biologically viable in the majority of higher plant species. As soon as border cells detach from root cap periphery, their metabolic activity dramatically increases in accordance with a differential gene expression from that in root cap cells. Recently, PsUGT1 and RCPME1, relevant to the early and late stage of border cell development, respectively, have been cloned and functionally identified. Border cells can synthesize specially and export a diverse array of chemicals including anthocyanins, antibiotics, special enzymes and other substances, that either inhibit or promote the growth of other entities in rhizosphere such as bacteria, fungi, viruses, and nematodes, and also antagonize some toxic chemicals around the root tip in soil such as aluminum toxicity. Therefore, there are multiple biological roles played by border cells during plant growth and development.展开更多
Aim To evaluate the bioequivalence of two brands of losartan/hydrochlorothiazide (50 mg/12.5 mg) compound tablets in healthy Chinese male volunteers. Methods An open, randomized, single-dose, two-period cross-over s...Aim To evaluate the bioequivalence of two brands of losartan/hydrochlorothiazide (50 mg/12.5 mg) compound tablets in healthy Chinese male volunteers. Methods An open, randomized, single-dose, two-period cross-over study with a wash-out period of 7 d was conducted. Twenty healthy male volunteers were given a single dose 50 mg losartan/12.5 mg hydrochlorothiazide of either test (T) or reference (R) compound tablets, respectively. Blood samples were collected up to 48 h after oral administration. The concentrations of losartan and hydrochlorothiazide in plasma were determined by a validated HPLC-ESI-MS method. Results In the case of losartan, the 90% confidence intervals of two one-side test for percent ratios with a significant level (α) of 0. 05 were 86% - 112% for AUC0-12 and 89% - 134% for Cmax, respectively, which were within the interval proposed in the Chinese Pharmacopoeia, 80% - 125% of AUC and 70% - 143% of Cmax, respectively. Similarly, the 90% confidence intervals for percent ratios were 85% - 100% and 75% - 102% for hydrochlorothiazide, both of which fell into the accepted interval. Conclusion Two immediate-release compound tablets of losartan/hydrochlorothiazide are bioequivalent from a statistical standpoint in the extent and rate of absorption from the single-dose study in healthy Chinese male volunteers.展开更多
Aim To evaluate the pharmacokinetics and bioequivalence of domestic pantoprazole sodium enteric-coated tablets as compared with imported pantoprazole enteric-coated tablets. Methods This was an open randomized, two pe...Aim To evaluate the pharmacokinetics and bioequivalence of domestic pantoprazole sodium enteric-coated tablets as compared with imported pantoprazole enteric-coated tablets. Methods This was an open randomized, two periods cross over study on twenty healthy male volunteers. The pantoprazole concentrations in plasma after an oral dose of 40 mg pantoprzaole preparations were determined by a HPLC-UV method. Non-compartmental method was used for the calculation of pharmacokinetic parameters. Logarithm-transformed Cmax and A UC were analyzed by the analysis of variance (ANOVA) with 90% confidence intervals. Results The main pharmacokinetics parameters of domestic pantoprazole sodium enteric-coated tablets and imported pantoprazole sodium enteric-coated tablets were as following: Cmax (3610 ± 956), (3466 ± 1209) ng·mL^-1, tmax (3.00 ± 0.40), (3.00 ± 0.46) h, AUC0-t (8140 ± 5065), (8390 ± 5474) ng·h·mL^-1, AUC0-∞ (8293 ± 5094), (8625 ± 5606) ng·h·mL^-1, t1/2 (1.61 ± 0.28), (1.85 ± 0.27) h, respectively. Conclusion Domestic pantoprazole sodium enteric-coated tablets were bioequivalent with the imported pantoprazole sodium enteric-coated tablets.展开更多
Fe3Al alloys with nearly full density were fabricated by plasma activated sintering(PAS) and hot pressing(HP) from mechanical alloyed Fe-28%Al(mole fraction) powders,respectively.It is found that A2-type Fe3Al a...Fe3Al alloys with nearly full density were fabricated by plasma activated sintering(PAS) and hot pressing(HP) from mechanical alloyed Fe-28%Al(mole fraction) powders,respectively.It is found that A2-type Fe3Al alloys were obtained by PAS,and they had a heterogeneous grain size distribution,most areas had a grain size smaller than 500 nm,and other areas had a grain size of about 1 μm.Different to PAS,D03-type Fe3Al alloys with a grain size of of 1-2 μm were obtained by HP.The compression testing results show that yield strength values of Fe3Al alloys fabricated by PAS and HP are almost equal at an elevated temperature,and the compression yield strength was about 100 MPa for all at 800 ℃.The room temperature compression ductility of Fe3Al alloys by PAS was about 20%,which was superior to that of Fe3Al alloys prepared by HP and casting.展开更多
Aim To establish a LC-MS method for determining the concentration of nifedipine in human plasma and to evaluate the pharmacokinetic characteristics of nifedipine sustained-release tablets. Methods A XB-C18 (5 μm, 4....Aim To establish a LC-MS method for determining the concentration of nifedipine in human plasma and to evaluate the pharmacokinetic characteristics of nifedipine sustained-release tablets. Methods A XB-C18 (5 μm, 4.6 mm ×150 mm) column and a mobile phase of methanol: 0.01 mol·L^-1ammonium acetate (60:40, V/V) were used to separate nifedipine, the detections was accuracy under atmosperic pressure electronic spray ionization (AP-ESI) mode and ion mass spectrum (m/z) of 314.9 [M+H]^+ for nifedipine, and 320.8 [M+H]^+ for lorazepam (Internal Standard, IS). Results The linear range of nifedipine was 0.3 - 80 ng·mL^-1 ( r = 0.9997), and the limit of quantitation (LOQ) was 0.3 ng·mL^-1. The nifedipine pharmacokinetic parameters after a single dose of 20 mg nifedipine sustained-release tablets test (T) or reference (R) were as the followings, t1/2 (6.73 ± 2.00) h and (7.04 ± 2.18) h, Tmax (4.28 ± 0.70) h and (4.48 ± 0.70) h, Cmax(39.66 ± 10.58) ng·mL^-1 and (40.19 ± 10.97) ng·mL^-1, AUC0-36 (391.63 ± 108.55) ng·mL^-1·h and (387.57 ± 121.51) ng·mL^-1·h, and AUC0-∞ (408.28 ± 121.16) ng·mL^-1·h and (406.15 ± 133.13) ng·mL^-1·h. The relative bioavailability of nifedipine sustained-release tablets (test) was (103.02 ± 13.93) %. Conclusion LC-MS method for the determination of concentrations of nifedipine in human plasma was sensitive and accurate, and could be used in nifedipine bioavailability and pharmacokinetic studies.展开更多
Aim To develop a rapid, simple, and sensitive high-performance liquid chromatographic (HPLC) method for the determination of cefprozil in human plasma and to study its pharmacokinetics and bioequivalence after 0.5 g o...Aim To develop a rapid, simple, and sensitive high-performance liquid chromatographic (HPLC) method for the determination of cefprozil in human plasma and to study its pharmacokinetics and bioequivalence after 0.5 g oral doses of cefprozil granules and tablets. Methods The blood concentration of cefprozil was analyzed after extracted with 6% trichloroacetic acid, using tinidazole as internal standard (I.S.). A C_ 18 column was used to separate cefprozil with mobile phase of methanol, purified water and glac...展开更多
Since nuclear extrusion was rediscovered in young Allium scale by S.H.WU in the years of 1950's systematic investigations on this phenomenon were carried out with various kinds of microscopic techniques a...Since nuclear extrusion was rediscovered in young Allium scale by S.H.WU in the years of 1950's systematic investigations on this phenomenon were carried out with various kinds of microscopic techniques and plant materials to collect more effective evidence to clarify the debate about whether the nuclear extrusion is an artifact or normal event. In the cooperative research of S. H. WU and C. H. LOU the normality of the occurrence of nuclear extrusion either in growing part of plant or in senescent tissue has been confirmed. This event is intimately associated with the physiological state of the tissues/cells and may play an important role in redistribution and reutilization of cell contents. Based on the results obtained a hypothesis of intercellular movement of protoplasm as a means of translocation of organic material in plants was suggested. Chromatin extrusion was also discovered in the pollen mother cells (cytomixis) of certain angiosperms by G. C. ZHENG and his team. Intercellular migration of chromatin appears most frequently at the stage of synizesis. Cytomixis has been studied in relation to variation and evolution. Chromosome aberration has been considered to be closely associated with chromatin extrusion. By vital microscopic observations of the live tissues of garlic (Allium sativum L.) bud and wheat (Triticum aestivum L.) ovule combined with cinemicroscopy and video recording it has been uncovered that, not only the nuclear material but also the cytoplasm could traverse the intercellular channels by vigorous contraction and expansion, and they may simultaneously extrude out of a cell but often asynchronously migrate from one cell to another. The involvement of cytoplasmic constituents in intercellular migration was also detected in pollen mother cells with electron microscopy. Regarding the mechanism of intercellular movement a series of experiments provide convincing evidence showing that this kind of movement is an active metabolic process closely coupled with energy metabolism, and the motive power for driving the extrusion may be supplied by the contractile proteins in protoplasm.展开更多
Aim To establish a HPLC method for the determination of bicalutamide plasma concentration and to evaluate the bioequivalence of bicalutamide capsules (test) and tablets (reference). Methods A single oral dose of 5...Aim To establish a HPLC method for the determination of bicalutamide plasma concentration and to evaluate the bioequivalence of bicalutamide capsules (test) and tablets (reference). Methods A single oral dose of 50 mg bicalutamide capsules or tablets were given to 48 Chinese healthy volunteers in a one period parallel design test. Bicalutamide in plasma was analyzed using a XB-C18 column with a mobile phase of acetonitrile-water (60:40, V/V) and the dectection wavelength of 272 nm and it is pharmacokinetic parameters were calculated and evaluated using DAS2.0. Results The linear range of bicalutamide was 10 - 1200 ng·mL^-1. The main pharmacokinetic parameters of the test and reference were as the followings, t1/2 (138.36 ± 32.03) and (146.12 ± 27.04) h, Tmax (17.17 ± 4.65) and (16.92 ± 4.85) h, Cmax(910.83 ± 130.49) and (868.71 ± 115.35) ng·mL^-1 AUC0-672(172437.08 ± 3986.07) and (176842.34 ± 35733.85) ng·mL^-1·h, and AUC0-∞ (179456.55 ± 43127.65) and (185270.39 ± 39688.63) ng·mL^-1·h, respectively. The two-one side t-test analysis showed that the confidence intervals of Crux, A UC0-672 and A UC0-∞ were (98.9% - 100.7%), (98.8% - 100.6%) and (99.7% - 101.7%), respectively. Conclusion The relative bioavailability of bicalutamide capsules was 97.51%. The bioequivalence was demonstrated by the two-one side t-test展开更多
The crystal structures,compositions and phase relations of the intermetallics of Mg-Zn-Ce system in the Mg-rich corner at 400 ℃ were identified through equilibrium alloy method.For Mg-Zn-Ce system,there is a linear t...The crystal structures,compositions and phase relations of the intermetallics of Mg-Zn-Ce system in the Mg-rich corner at 400 ℃ were identified through equilibrium alloy method.For Mg-Zn-Ce system,there is a linear ternary compound(T phase),whose chemical formula is(Mg1-xZnx)11Ce.The range of Zn content in T phase is from 9.6% to 43.6%(molar fraction).The crystal structure of T phase is C-centered orthorhombic lattice with lattice parameters of a=0.96-1.029 nm,b=1.115-1.204 nm,c=0.940-1.015 nm.And the lattice parameters of T phase are decreasing a little with increasing Zn content.According to the results of composition and crystal structure,the maximal solubility of Zn in Mg12Ce is about 7.8%(molar fraction),and the chemical formula of the solid solution can be identified as(Mg1-xZnx)12Ce.The isothermal section of Mg-Zn-Ce system in Mg-rich corner at 400 ℃ was constructed.展开更多
Abstract Melatonin (N-acetyi-5-methoxytryptamine) is a well-known animal hormone, which is synthesized and secreted by pineal gland and takes part in the regulation of circadian rhythm in animals. At present it has ...Abstract Melatonin (N-acetyi-5-methoxytryptamine) is a well-known animal hormone, which is synthesized and secreted by pineal gland and takes part in the regulation of circadian rhythm in animals. At present it has been observed that melatonin is widely existed in higher plants while there have no enough studies on functions of melatonin in plants. Researches have already indicated that the possible functions of melatonin in plants include regulating photoperiod, participating in growth regulation, clearing active oxygen, and promoting activity of antioxidase. General reviews upon functions of melatonin in plants are made upon experiments in recent years. We fo-cus on the demonstrated and predicted biological functions of melatonin in plants to bring researchers up to date on this field. The weakness in present studies and the main research directions are also pointed out.展开更多
Physical and mathematical models as well as calculation methods of nitrogen bed on porous media have been introduced to evaluate the structural parameters of mesoporous materials. Kelvin's equation is a link between ...Physical and mathematical models as well as calculation methods of nitrogen bed on porous media have been introduced to evaluate the structural parameters of mesoporous materials. Kelvin's equation is a link between the relative adsorbate pressure, the mean pore radius, and pore capillarity on the basis of macroscopic capillary condensation. However, Kelvin's equation has been identified that it underestimates the calculated pore size of a material especially in the boundary of pore size which is between 2 and 4 nm.Various modifications on Kelvin's equation were mentioned in order to develop a new model to improve the accuracy of pore size calculation. The problems on conventional mathematical models were analyzed and discussed. A number of calculation methods on physisorption and pore size, especially fundamental theories of physisorption, basis of models and their deficiencies are reviewed. It can provide guidance on developing a modified Kelvin's equation for pore size calculation.展开更多
The Mg-Ni hydride was prepared by hydriding combustion synthesis under a high magnetic field. The dehydriding kinetics of the hydrides was measured under the isothermal and non-isothermal conditions. A model was appli...The Mg-Ni hydride was prepared by hydriding combustion synthesis under a high magnetic field. The dehydriding kinetics of the hydrides was measured under the isothermal and non-isothermal conditions. A model was applied to analyzing the kinetics behavior of Mg-Ni hydride. The calculation results show that the theoretical value and the experimental data can reach a good agreement, especially in the case of non-isothermal dehydriding. The rate-controlling step is the diffusion of hydrogen atoms in the solid solution. The sample prepared under magnetic field of 6 T under the isothermal condition can reach the best performance. The similar tendency was observed under the non-isothermal condition and the reason was discussed.展开更多
The phase equilibria and compositions at the Mg-rich corner of the Mg?Zn?Al ternary system at 335 °C were systemically investigated through the equilibrated alloy method by using X-ray diffraction (XRD) and scann...The phase equilibria and compositions at the Mg-rich corner of the Mg?Zn?Al ternary system at 335 °C were systemically investigated through the equilibrated alloy method by using X-ray diffraction (XRD) and scanning electron microscopy (SEM) assisted with energy dispersive spectroscopy of X-ray (EDS). It is experimentally testified that theα-Mg solid solution is not in equilibrium with the Mg32(Al, Zn)49 (τ) ternary intermetallic compound orq quasicrystalline phase, but only in equilibrium with one ternary intermetallic compound Al5Mg11Zn4 (φ). The whole composition range of theφ phase was also obtained at 335 °C, i.e., 52.5%?56.4% Mg, 13.6%?24.0% Al, 19.6%?33.9% Zn (mole fraction). The solubility of Al in the MgZn phase is remarkably more than that in the Mg7Zn3 phase, and the maximum is about 8.6% Al. Aluminum and zinc are simultaneously soluble in theα-Mg solid solution.展开更多
Flower-like tin oxide-supported platinum(Pt/SnOx) with a hierarchical structure was synthesized by a hydrothermal method and characterized by XRD,SEM,TEM,high resolution TEM,XPS and nitrogen adsorption.The flower-li...Flower-like tin oxide-supported platinum(Pt/SnOx) with a hierarchical structure was synthesized by a hydrothermal method and characterized by XRD,SEM,TEM,high resolution TEM,XPS and nitrogen adsorption.The flower-like Pt/SnOx microspheres of 1 μm in diameter were composed of staggered petal-like nanosheets with a thickness of 20 nm.Pt nanoparticles(NPs) of 2-3 nm were well dispersed on the SnOx nanosheets.The catalyst was tested in the catalytic oxidation of gaseous formaldehyde(HCHO) at room temperature,and exhibited enhanced activity compared to Pt NPs supported on commercial SnO and ground SnOx.HCHO removal of 87%was achieved over the hierarchical Pt/SnOx after 1 h of reaction,which was 1.5 times that over the ground SnOx-supported Pt(Pt/g-SnOx),and the high activity was maintained after six recycles,showing the high stability of this catalyst.HCHO decomposition kinetics was modeled as a second order reaction.The reaction rate constant for Pt/SnOx was 5.6 times higher than Pt/g-SnOx.The hierarchical pore structure was beneficial for the diffusion and adsorption of HCHO molecules,and the highly dispersed Pt NPs on the SnOx nanosheets were the active sites for the oxidative decomposition of HCHO into CO2 and H2O.This study provided a promising approach for designing efficient catalysts for indoor HCHO removal at ambient temperature.展开更多
The hydrogen plasma degradation of transparent conduction oxides (TCO) is studied for hydrogenated microcrystalline Si(μc-Si:H)prepared by plasma enhanced chemical vapor deposition (PECVD). TCO films such as S...The hydrogen plasma degradation of transparent conduction oxides (TCO) is studied for hydrogenated microcrystalline Si(μc-Si:H)prepared by plasma enhanced chemical vapor deposition (PECVD). TCO films such as SnO2 and SnO2/ZnO bi-layer films were exposed to atomic H at various substrate temperatures and for various treatment times. A decrease in the transmittance due to reduction by atomic H was scarcely observed for SnO2 / ZnO bi-layer,while a decrease for SnO2 was found to depend strongly on the substrate temperature. The resistivity of SnO2 films decreases significantly when substrate temperature exceeds 150℃in H-plasma. However, H-plasma treatment has little impact on the resistivity of SnO2/ZnO bi-layer film. The reason for the decrease in the transmittance is the appearance of metallic Sn on the surface, and under this condition no μc-Si: H film is deposited. SnO2/ZnO bi-layer is very effective for the suppression of the reduction of TCO during μc-Si:H deposition. The performance of microcrystalline silicon solar cells fabricated on ZnO/SnO2/glass is also investigated.展开更多
文摘Root border cells, previously referred to as sloughed root cap cells, is a special cell population which separates in large numbers from the periphery of the root cap and accumulates in the root tip. Recent evidence reveals that border cells, whose development is regulated by endogenous and exogenous signals, are biologically viable in the majority of higher plant species. As soon as border cells detach from root cap periphery, their metabolic activity dramatically increases in accordance with a differential gene expression from that in root cap cells. Recently, PsUGT1 and RCPME1, relevant to the early and late stage of border cell development, respectively, have been cloned and functionally identified. Border cells can synthesize specially and export a diverse array of chemicals including anthocyanins, antibiotics, special enzymes and other substances, that either inhibit or promote the growth of other entities in rhizosphere such as bacteria, fungi, viruses, and nematodes, and also antagonize some toxic chemicals around the root tip in soil such as aluminum toxicity. Therefore, there are multiple biological roles played by border cells during plant growth and development.
文摘Aim To evaluate the bioequivalence of two brands of losartan/hydrochlorothiazide (50 mg/12.5 mg) compound tablets in healthy Chinese male volunteers. Methods An open, randomized, single-dose, two-period cross-over study with a wash-out period of 7 d was conducted. Twenty healthy male volunteers were given a single dose 50 mg losartan/12.5 mg hydrochlorothiazide of either test (T) or reference (R) compound tablets, respectively. Blood samples were collected up to 48 h after oral administration. The concentrations of losartan and hydrochlorothiazide in plasma were determined by a validated HPLC-ESI-MS method. Results In the case of losartan, the 90% confidence intervals of two one-side test for percent ratios with a significant level (α) of 0. 05 were 86% - 112% for AUC0-12 and 89% - 134% for Cmax, respectively, which were within the interval proposed in the Chinese Pharmacopoeia, 80% - 125% of AUC and 70% - 143% of Cmax, respectively. Similarly, the 90% confidence intervals for percent ratios were 85% - 100% and 75% - 102% for hydrochlorothiazide, both of which fell into the accepted interval. Conclusion Two immediate-release compound tablets of losartan/hydrochlorothiazide are bioequivalent from a statistical standpoint in the extent and rate of absorption from the single-dose study in healthy Chinese male volunteers.
文摘Aim To evaluate the pharmacokinetics and bioequivalence of domestic pantoprazole sodium enteric-coated tablets as compared with imported pantoprazole enteric-coated tablets. Methods This was an open randomized, two periods cross over study on twenty healthy male volunteers. The pantoprazole concentrations in plasma after an oral dose of 40 mg pantoprzaole preparations were determined by a HPLC-UV method. Non-compartmental method was used for the calculation of pharmacokinetic parameters. Logarithm-transformed Cmax and A UC were analyzed by the analysis of variance (ANOVA) with 90% confidence intervals. Results The main pharmacokinetics parameters of domestic pantoprazole sodium enteric-coated tablets and imported pantoprazole sodium enteric-coated tablets were as following: Cmax (3610 ± 956), (3466 ± 1209) ng·mL^-1, tmax (3.00 ± 0.40), (3.00 ± 0.46) h, AUC0-t (8140 ± 5065), (8390 ± 5474) ng·h·mL^-1, AUC0-∞ (8293 ± 5094), (8625 ± 5606) ng·h·mL^-1, t1/2 (1.61 ± 0.28), (1.85 ± 0.27) h, respectively. Conclusion Domestic pantoprazole sodium enteric-coated tablets were bioequivalent with the imported pantoprazole sodium enteric-coated tablets.
基金Project (50871084) supported by the National Natural Science Foundation of ChinaProject (2009AA032601) supported by the National High Technology Research and Development Program of China
文摘Fe3Al alloys with nearly full density were fabricated by plasma activated sintering(PAS) and hot pressing(HP) from mechanical alloyed Fe-28%Al(mole fraction) powders,respectively.It is found that A2-type Fe3Al alloys were obtained by PAS,and they had a heterogeneous grain size distribution,most areas had a grain size smaller than 500 nm,and other areas had a grain size of about 1 μm.Different to PAS,D03-type Fe3Al alloys with a grain size of of 1-2 μm were obtained by HP.The compression testing results show that yield strength values of Fe3Al alloys fabricated by PAS and HP are almost equal at an elevated temperature,and the compression yield strength was about 100 MPa for all at 800 ℃.The room temperature compression ductility of Fe3Al alloys by PAS was about 20%,which was superior to that of Fe3Al alloys prepared by HP and casting.
文摘Aim To establish a LC-MS method for determining the concentration of nifedipine in human plasma and to evaluate the pharmacokinetic characteristics of nifedipine sustained-release tablets. Methods A XB-C18 (5 μm, 4.6 mm ×150 mm) column and a mobile phase of methanol: 0.01 mol·L^-1ammonium acetate (60:40, V/V) were used to separate nifedipine, the detections was accuracy under atmosperic pressure electronic spray ionization (AP-ESI) mode and ion mass spectrum (m/z) of 314.9 [M+H]^+ for nifedipine, and 320.8 [M+H]^+ for lorazepam (Internal Standard, IS). Results The linear range of nifedipine was 0.3 - 80 ng·mL^-1 ( r = 0.9997), and the limit of quantitation (LOQ) was 0.3 ng·mL^-1. The nifedipine pharmacokinetic parameters after a single dose of 20 mg nifedipine sustained-release tablets test (T) or reference (R) were as the followings, t1/2 (6.73 ± 2.00) h and (7.04 ± 2.18) h, Tmax (4.28 ± 0.70) h and (4.48 ± 0.70) h, Cmax(39.66 ± 10.58) ng·mL^-1 and (40.19 ± 10.97) ng·mL^-1, AUC0-36 (391.63 ± 108.55) ng·mL^-1·h and (387.57 ± 121.51) ng·mL^-1·h, and AUC0-∞ (408.28 ± 121.16) ng·mL^-1·h and (406.15 ± 133.13) ng·mL^-1·h. The relative bioavailability of nifedipine sustained-release tablets (test) was (103.02 ± 13.93) %. Conclusion LC-MS method for the determination of concentrations of nifedipine in human plasma was sensitive and accurate, and could be used in nifedipine bioavailability and pharmacokinetic studies.
文摘Aim To develop a rapid, simple, and sensitive high-performance liquid chromatographic (HPLC) method for the determination of cefprozil in human plasma and to study its pharmacokinetics and bioequivalence after 0.5 g oral doses of cefprozil granules and tablets. Methods The blood concentration of cefprozil was analyzed after extracted with 6% trichloroacetic acid, using tinidazole as internal standard (I.S.). A C_ 18 column was used to separate cefprozil with mobile phase of methanol, purified water and glac...
文摘Since nuclear extrusion was rediscovered in young Allium scale by S.H.WU in the years of 1950's systematic investigations on this phenomenon were carried out with various kinds of microscopic techniques and plant materials to collect more effective evidence to clarify the debate about whether the nuclear extrusion is an artifact or normal event. In the cooperative research of S. H. WU and C. H. LOU the normality of the occurrence of nuclear extrusion either in growing part of plant or in senescent tissue has been confirmed. This event is intimately associated with the physiological state of the tissues/cells and may play an important role in redistribution and reutilization of cell contents. Based on the results obtained a hypothesis of intercellular movement of protoplasm as a means of translocation of organic material in plants was suggested. Chromatin extrusion was also discovered in the pollen mother cells (cytomixis) of certain angiosperms by G. C. ZHENG and his team. Intercellular migration of chromatin appears most frequently at the stage of synizesis. Cytomixis has been studied in relation to variation and evolution. Chromosome aberration has been considered to be closely associated with chromatin extrusion. By vital microscopic observations of the live tissues of garlic (Allium sativum L.) bud and wheat (Triticum aestivum L.) ovule combined with cinemicroscopy and video recording it has been uncovered that, not only the nuclear material but also the cytoplasm could traverse the intercellular channels by vigorous contraction and expansion, and they may simultaneously extrude out of a cell but often asynchronously migrate from one cell to another. The involvement of cytoplasmic constituents in intercellular migration was also detected in pollen mother cells with electron microscopy. Regarding the mechanism of intercellular movement a series of experiments provide convincing evidence showing that this kind of movement is an active metabolic process closely coupled with energy metabolism, and the motive power for driving the extrusion may be supplied by the contractile proteins in protoplasm.
文摘Aim To establish a HPLC method for the determination of bicalutamide plasma concentration and to evaluate the bioequivalence of bicalutamide capsules (test) and tablets (reference). Methods A single oral dose of 50 mg bicalutamide capsules or tablets were given to 48 Chinese healthy volunteers in a one period parallel design test. Bicalutamide in plasma was analyzed using a XB-C18 column with a mobile phase of acetonitrile-water (60:40, V/V) and the dectection wavelength of 272 nm and it is pharmacokinetic parameters were calculated and evaluated using DAS2.0. Results The linear range of bicalutamide was 10 - 1200 ng·mL^-1. The main pharmacokinetic parameters of the test and reference were as the followings, t1/2 (138.36 ± 32.03) and (146.12 ± 27.04) h, Tmax (17.17 ± 4.65) and (16.92 ± 4.85) h, Cmax(910.83 ± 130.49) and (868.71 ± 115.35) ng·mL^-1 AUC0-672(172437.08 ± 3986.07) and (176842.34 ± 35733.85) ng·mL^-1·h, and AUC0-∞ (179456.55 ± 43127.65) and (185270.39 ± 39688.63) ng·mL^-1·h, respectively. The two-one side t-test analysis showed that the confidence intervals of Crux, A UC0-672 and A UC0-∞ were (98.9% - 100.7%), (98.8% - 100.6%) and (99.7% - 101.7%), respectively. Conclusion The relative bioavailability of bicalutamide capsules was 97.51%. The bioequivalence was demonstrated by the two-one side t-test
基金Project(N110323017) supported by the Fundamental Research Funds for the Central Universities,ChinaProject(E2010001390) supported by the Natural Science Foundation of Hebei Province,China
文摘The crystal structures,compositions and phase relations of the intermetallics of Mg-Zn-Ce system in the Mg-rich corner at 400 ℃ were identified through equilibrium alloy method.For Mg-Zn-Ce system,there is a linear ternary compound(T phase),whose chemical formula is(Mg1-xZnx)11Ce.The range of Zn content in T phase is from 9.6% to 43.6%(molar fraction).The crystal structure of T phase is C-centered orthorhombic lattice with lattice parameters of a=0.96-1.029 nm,b=1.115-1.204 nm,c=0.940-1.015 nm.And the lattice parameters of T phase are decreasing a little with increasing Zn content.According to the results of composition and crystal structure,the maximal solubility of Zn in Mg12Ce is about 7.8%(molar fraction),and the chemical formula of the solid solution can be identified as(Mg1-xZnx)12Ce.The isothermal section of Mg-Zn-Ce system in Mg-rich corner at 400 ℃ was constructed.
基金Supported by National 863 Project of China(2012AA101801)"Twelfth Five-Year"Plan for Science&Technology Project(2011BAD17B01)Chinese Universities Scientific Fund(2009-2-06)~~
文摘Abstract Melatonin (N-acetyi-5-methoxytryptamine) is a well-known animal hormone, which is synthesized and secreted by pineal gland and takes part in the regulation of circadian rhythm in animals. At present it has been observed that melatonin is widely existed in higher plants while there have no enough studies on functions of melatonin in plants. Researches have already indicated that the possible functions of melatonin in plants include regulating photoperiod, participating in growth regulation, clearing active oxygen, and promoting activity of antioxidase. General reviews upon functions of melatonin in plants are made upon experiments in recent years. We fo-cus on the demonstrated and predicted biological functions of melatonin in plants to bring researchers up to date on this field. The weakness in present studies and the main research directions are also pointed out.
文摘Physical and mathematical models as well as calculation methods of nitrogen bed on porous media have been introduced to evaluate the structural parameters of mesoporous materials. Kelvin's equation is a link between the relative adsorbate pressure, the mean pore radius, and pore capillarity on the basis of macroscopic capillary condensation. However, Kelvin's equation has been identified that it underestimates the calculated pore size of a material especially in the boundary of pore size which is between 2 and 4 nm.Various modifications on Kelvin's equation were mentioned in order to develop a new model to improve the accuracy of pore size calculation. The problems on conventional mathematical models were analyzed and discussed. A number of calculation methods on physisorption and pore size, especially fundamental theories of physisorption, basis of models and their deficiencies are reviewed. It can provide guidance on developing a modified Kelvin's equation for pore size calculation.
基金Project(51464008) supported by the National Natural Science Foundation of ChinaProject(KY[2012]004) supported by the Key Laboratory Item of Education Office in Guizhou Province,China
文摘The Mg-Ni hydride was prepared by hydriding combustion synthesis under a high magnetic field. The dehydriding kinetics of the hydrides was measured under the isothermal and non-isothermal conditions. A model was applied to analyzing the kinetics behavior of Mg-Ni hydride. The calculation results show that the theoretical value and the experimental data can reach a good agreement, especially in the case of non-isothermal dehydriding. The rate-controlling step is the diffusion of hydrogen atoms in the solid solution. The sample prepared under magnetic field of 6 T under the isothermal condition can reach the best performance. The similar tendency was observed under the non-isothermal condition and the reason was discussed.
基金Projects(50901017,51171043,51271053)supported by the National Natural Science Foundation of ChinaProject(20090042120008)supported by the Doctoral Program Foundation of Institutions of Higher Education of ChinaProject(2011BAE22B04-2)supported by National Key Technology R&D Program of China during the Twelfth Five-Year Plan Period
文摘The phase equilibria and compositions at the Mg-rich corner of the Mg?Zn?Al ternary system at 335 °C were systemically investigated through the equilibrated alloy method by using X-ray diffraction (XRD) and scanning electron microscopy (SEM) assisted with energy dispersive spectroscopy of X-ray (EDS). It is experimentally testified that theα-Mg solid solution is not in equilibrium with the Mg32(Al, Zn)49 (τ) ternary intermetallic compound orq quasicrystalline phase, but only in equilibrium with one ternary intermetallic compound Al5Mg11Zn4 (φ). The whole composition range of theφ phase was also obtained at 335 °C, i.e., 52.5%?56.4% Mg, 13.6%?24.0% Al, 19.6%?33.9% Zn (mole fraction). The solubility of Al in the MgZn phase is remarkably more than that in the Mg7Zn3 phase, and the maximum is about 8.6% Al. Aluminum and zinc are simultaneously soluble in theα-Mg solid solution.
基金supported by the National Natural Science Foundation of China (51320105001, 51372190, 21573170, 51272199, 21433007)the National Basic Research Program of China (973 program, 2013CB632402)+2 种基金the Natural Science Foundation of Hubei Province (2015CFA001)the Fundamental Research Funds for the Central Universities (WUT: 2015-Ⅲ-034)Innovative Research Funds of SKLWUT (2015-ZD-1)~~
文摘Flower-like tin oxide-supported platinum(Pt/SnOx) with a hierarchical structure was synthesized by a hydrothermal method and characterized by XRD,SEM,TEM,high resolution TEM,XPS and nitrogen adsorption.The flower-like Pt/SnOx microspheres of 1 μm in diameter were composed of staggered petal-like nanosheets with a thickness of 20 nm.Pt nanoparticles(NPs) of 2-3 nm were well dispersed on the SnOx nanosheets.The catalyst was tested in the catalytic oxidation of gaseous formaldehyde(HCHO) at room temperature,and exhibited enhanced activity compared to Pt NPs supported on commercial SnO and ground SnOx.HCHO removal of 87%was achieved over the hierarchical Pt/SnOx after 1 h of reaction,which was 1.5 times that over the ground SnOx-supported Pt(Pt/g-SnOx),and the high activity was maintained after six recycles,showing the high stability of this catalyst.HCHO decomposition kinetics was modeled as a second order reaction.The reaction rate constant for Pt/SnOx was 5.6 times higher than Pt/g-SnOx.The hierarchical pore structure was beneficial for the diffusion and adsorption of HCHO molecules,and the highly dispersed Pt NPs on the SnOx nanosheets were the active sites for the oxidative decomposition of HCHO into CO2 and H2O.This study provided a promising approach for designing efficient catalysts for indoor HCHO removal at ambient temperature.
文摘The hydrogen plasma degradation of transparent conduction oxides (TCO) is studied for hydrogenated microcrystalline Si(μc-Si:H)prepared by plasma enhanced chemical vapor deposition (PECVD). TCO films such as SnO2 and SnO2/ZnO bi-layer films were exposed to atomic H at various substrate temperatures and for various treatment times. A decrease in the transmittance due to reduction by atomic H was scarcely observed for SnO2 / ZnO bi-layer,while a decrease for SnO2 was found to depend strongly on the substrate temperature. The resistivity of SnO2 films decreases significantly when substrate temperature exceeds 150℃in H-plasma. However, H-plasma treatment has little impact on the resistivity of SnO2/ZnO bi-layer film. The reason for the decrease in the transmittance is the appearance of metallic Sn on the surface, and under this condition no μc-Si: H film is deposited. SnO2/ZnO bi-layer is very effective for the suppression of the reduction of TCO during μc-Si:H deposition. The performance of microcrystalline silicon solar cells fabricated on ZnO/SnO2/glass is also investigated.