Permeability determination and pharmacokinetic study of nobiletin in rat plasma and brain by validated high-performance liquid chromatography method

In the present study, we are reporting permeability and pharmacokinetics of nobiletin in rat plasma and brain, using a validated reverse phase high performance liquid chromatographic method. Protein precipitation method was used for the extraction of nobiletin and coumarin (IS) from rat plasma and brain tissue. The system was run in isocratic mode with mobile phase consisting of potassium dihydrogen ortho-phosphate (pH 4.5; 0.04 mM) and acetonitrile in ratio of 50:50, v/v. The total chromatographic run time was 9.0 min. The method was proved to be accurate and precise at linearity range of 0.05–10 μg/mL with a correlation coefficient (r) of ≥ 0.994 in rat plasma and ≥ 0.995 in rat brain. The intra- and inter-day precision and accuracy values are found to be within the assay variability limits as per the FDA guidelines. Nobiletin was found stable in the battery of stability studies viz., bench-top, auto-sampler, freeze/thaw cycles and long term storage in a freezer at − 70 ± 10 °C. Maximum concentrations of nobiletin in both plasma and brain were observed at 1 h after single oral dosing (50 mg/kg). The maximum concentration in plasma and brain were 1.78 and 4.20 μg/mL, respectively. The AUC_0–t in plasma and brain were 7.49 and 20.66 μg·h/mL, respectively. The mean elimination half life (t_1/2) in plasma and brain were 1.80 and 11.42 h, respectively. The Parallel Artificial Membrane Permeability Assay (PAMPA) permeability of nobiletin was found to be high at both pH 4.0 and 7.0.     

辽细辛精油对黄瓜灰霉病菌菌丝体细胞膜通透性的影响

以辽细辛精油为材料,以黄瓜灰霉病菌为靶标,采用干菌丝和鲜菌丝两种处理方法,测定了辽细辛精油对黄瓜灰霉病菌菌丝体电导率的影响,结果表明,无论是干菌丝还是鲜菌丝,精油处理后灰霉病菌菌丝体的电导率均随着精油处理浓度的加大而提高、随处理时间的延长而提高.说明辽细辛精油对黄瓜灰霉病菌菌丝体细胞膜的通透性具有一定影响,可引起细胞膜...     

The fractal characterization of pore structure for some numerical rocks and prediction of permeabilities

This paper uses the fractal theory of pore structures for porous media to study the fractal characterization of pore structure for nine numerical rocks. The results show that the fractal dimension of solid phase is usually greater than the pore fractal dimension, and its fractal scaling regions is less than the one of pore phase. This indicates that the numerical rock is an approximate two-phase fractal porous media. The porosities, volume fractions and permeabilities of nine numerical rocks are predicted. The results show that the fractal theory about pore structures of numerical rocks is effective in describing the porosity and permeability. Moreover, it seems to be more effective for solid phase in approximate two-phase fractal porous media. When predicting permeability using the fractal theory, it is very important to accurately determine the maximum pore size and the range of statistical self-similarity. By comparing the two kinds of predicted permeabilities,it is found that the FT method used by this paper is more accurate, more general and less computational cost than the PNEM method which has been worldwide used.     

Mechanism analysis of permeability based on promoting coal matrix shrinkage by water jet

High pressure pulsed water jet (HPWJ) is a new technology of effectively improving coal seam permeability. However, the mechanism of increased permeability is not yet clear, which restricts the application of HPWJ in different coal seams. From the perspective of improving permeability by coal matrix shrinkage, the impelled dynamic equations is established based on analysis of coal dynamic effects by water jet. According to theoretical analysis of the stress state of coal matrix, it is concluded that HPWJ can promote coal matrix shrinkage, and the relationship equation between jet impact-coal matrix is derived. Besides, the gas seepage function in the coal slotted by the HPWJ is gained by using PM model, which provides theoretical support for generalizing the technology in the coal mine.     

盐逆境下甘蔗叶片膜脂过氧化与保护酶的活性

２个耐盐力不同的甘蔗品种桂糖１１（耐盐）和粤糖５７４２３（不耐盐），经过不同质量分数的ＮａＣｌ溶液处理后．甘蔗叶片质膜透性和膜脂过氧化产物丙二醛（ＭＤＡ）的含量均有不同程度的增加，其中又以不耐盐品种的粤糖５７４２３增加明显．与此同时，叶组织内过氧化物酶和超氧物歧化酶活性下降，过氧化氢酶活性除在较低质量分数的ＮａＣｌ下表现增强外，随ＮａＣｌ质量分数的提高也表现出活性下降的趋势．随着ＮａＣｌ质量分数的提高，叶片的叶绿素含量下降．以上变化的幅度均以不耐盐的品种粤糖５７４２３更加明显．     

喷施多效唑对盐胁迫下紫羊茅脯氨酸含量和膜透性的影响

本文采用50 mg·L^-1、100 mg·L^-1和200 mg·L^-1等3种浓度的多效唑喷施1%盐胁迫下的冷季型草坪草紫羊茅（Featua fubraL.）,以电导法测定叶片膜透性、茚三酮比色法测定叶片脯氨酸含量,探讨多效唑提高紫羊茅耐盐胁迫能力的效果。结果表明：只有50 mg·L^1浓度的多效唑可以使紫羊茅的脯氨酸含量极显著增高,但对膜透性的影响表现出随多效唑浓度增高膜透性也增高。     

过路黄对低温胁迫的生理反应

为探明过路黄低温致伤的生理特性，为其引种北移、栽培推广提供理论依据，研究了在低温（10，5，0，-5℃）胁迫下过路黄叶片内部生理生化反应的变化情况．结果表明，在低温胁迫下，过路黄叶片的质膜透性、保护酶活性和渗透调节物质均有明显的变化．在试验处理范围内，随着低温胁迫程度的加深和时间的延长，过路黄叶片的质膜透性上升；超氧化物歧化酶（SOD）活性先上升，后下降；游离脯氨酸（Pro）含量有明显增加；丙二醛（MDA）含量呈逐渐上升趋势．     

牛精液中药复方稀释液配方筛选研究

在种公牛精液商业稀释液的基础上,按6%、12%、24%和48%的4个水平向稀释液中分别添加4种中药复方提取液,制作0.25 ml细管冻精,解冻(40 ℃,10 s)后比较分析精子活率、顶体完整率、质膜完整性3个指标,以确定较优的中药稀释液配方.结果表明:添加了中药复方提取液的稀释液能更有效的冷冻保存牛精子细胞.其中,复方一和复方二的冷冻效果最佳.复方一在添加量为12%时精子活率、顶体完整率及质膜完整率分别为41.50%、40.14%和38.16%(P＜0.05),分别比对照组提高了10.67%、3.92%和5.50%;复方二在添加量为6%时,精子活率、顶体完整率、质膜完整率3项指标分别达到41.33%、41.59%和40.00%(P＜0.05),分别比对照组提高了10.50%、5.37%和7.34%.     

茄子黄萎病菌毒素对茄子叶片及愈伤组织细胞膜透性的影响

本文研究了不同抗病性品种的茄子幼苗在茄子黄萎病菌毒素处理后，其叶片及愈伤组织细胞膜透性的变化与抗病性的关系。结果表明：毒素处理后，茄子叶片及愈伤组织的细胞膜透性变化趋势基本一致，即随处理时间延长和毒素浓度增加，细胞膜透性增大，且感病品种蒙茄4号电导率值高于抗病品种粘毛茄。品种抗病性与细胞膜透性变化呈负相关。     

延边地区梨品种的抗寒性测定

采用以生物膜学说为依据的电导法，对延边地区常见梨品种的花芽及枝条组织进行了抗寒性测定．结果表明，不同梨品种的相对电导率和伤害率与温度呈线性相关，相关系数均达极显著水平．