Preparative isolation and purification of 12,13-dihydroxyeuparin from Radix Eupatorii Chinensis by high-speed counter-current chromatography

An efficient method for the isolation and purification of 12,13-dihydroxyeuparin from Radix Eupatorii Chinensis by high speed counter-current chromatography (HSCCC) was established in this paper. The ether extracts of Radix Eupatorii Chinensis were purified by HSCCC with a solvent system of hexyl hydride-ethyl acetate-methanol-water (1:2:1:2, v/v/v/v). The upper phase was used as the stationary phase and the lower phase as the mobile phase. About 8.4 mg of 12, 13-dihydroxyeuparin was obtained from 200 mg of ether extracts from Radix Eupatorii Chinensis in one-step HSCCC separation, with the purity of 96.71%, as determined by HPLC. After methanol- water recrystallization, the purity of 12,13-dihydroxyeuparin reached 99.83%. Such a simple and effective method was fairly useful to prepare pure compound as reference substances for related study on Radix Eupatorii Chinensis.

Counter-Wind Deep Current in the Northern Beibu Gulf in Boreal Winter

The Beibu Gulf is at an important geographical location and rich in gas, oil and biological resources. The observed currents showed that the current in the upper layer was opposite to that in the lower layer in boreal winter in the northern Beibu Gulf and it was northeastward in the lower layer. This northeastward current was reproduced by a 3 D baroclinic model in this study. It's found that the counter-wind deep current(referred to as ‘CWDC' hereinafter) strengthened from September to November but weakened from December to the following February. A closed meridional circulation in vertical direction was found in the northern Beibu Gulf, including CWDC, surface southwestward current, an upwelling, and a downwelling. The temporal variation process of the meridional circulation was similar to that of CWDC, with strength and range stronger in November and December than in other four months. Similar to the variation process of CWDC, the monsoon wind changed from weak easterly wind in September to strong northeasterly wind in November and December, and it was transformed into weak southeasterly wind in February again. The sensitive experiments showed that CWDC and the meridional circulation were controlled by the monsoon wind and were adjusted by heat flux-and tide-induced mixing, respectively. According to the momentum balance equation, it can be revealed the counter-wind deep current is a compensation current which is induced by the surface elevation gradient balanced by the Coriolis force, vertical diffusion and baroclinic pressure gradient.

Experimental investigation of different brines imbibition influences on co-and counter-current oil flows in carbonate reservoirs

Imbibition of water,as wetting phase in oil-wet fractured carbonate reservoirs,plays a key role in fluid flow between matrix and fracture system.The type of injected seawater and its chemistry would profoundly influence the imbibition process.In this study,the impact of smart water(a brine that its ions have been adjusted to facilitate oil recovery)and low salinity water on co-and counter-current imbibition processes for oil-wet carbonate cores has been experimentally investigated.The results show an increase of about 10% in oil recovery for co-and counter-currents for smart seawater imbibition compared to that of low salinity seawater.In addition,as a result of the influence of co-and counter-current on each other,by co-current removal from one core face,the countercurrent in the other face would be intensified by as much as about 75%.A close examination of different lengths(5,7 and 9 cm)of carbonate cores with the same permeability revealed that by decreasing porous medium length,the amount of counter-current producing oil would be decreased so that in the 5 cm core,counter current oil production will not happen.For similar core lengths by increasing permeability,the share of counter current flow would be decreased approximately 18% since the capillary pressure could not overcome non-wetting phase viscous forces.Considering the role of matrix length along with a modified brine(which is designed according to the matrix mixture)strengthen the relevant mechanisms to have more oil production so that the higher thickness of matrix causes the higher amount of co-current oil producing and consequently more total recovery.

An Economical Method for Preparative Purification of Five Alkaloids from Coptis Chinensis Franch by High-Speed Counter-Current Chromatography Using Singled Prepared Solvent System by GC

Coptis chinensis Franch, a widely used Traditional Chinese Medicine, shows various kinds of bioactivity. The major active components of the herb are considered to be alkaloids. Thus, preparative separation of these alkaloids is critical important for further pharmacology and mechanism studies. In the paper, five alkaloids from C. chinensis were purified by HSCCC using the solvent system composed of chloro-form-metha- nol-water (2:1:1, v/v/v) single prepared. The content of each solvent in solvent system were determined by gas chromatography (GC), then according the ratios of solvents in each phase to prepare the mobile and stationary phase respectively. And a comparative study was carried out between together preparation and single preparation of the solvent system. The purities and recoveries of all the products were over 98.5% and 92%. However, 134 mL chloroform, 336 mL methanol and 452 mL water were saved when the two phase were singled by GC. Our research showed an economical method for separating alkaloids from C. chinensis by HSCCC using the solvent system single prepared by GC.

Separation and Purification of Acetophenones from Cynanchum bengei Decne Root Bark by Combination of Silica Gel and High-speed Counter-current Chromatography

[Objectives] To develop a method for separation and purification of acetophenones from Cynanchum bengei Decne root bark by combination of silica gel and high-speed counter-current chromatography( HSCCC). [Methods]The crude extract of Cynanchum bengei Decne root bark was separated by silica gel column chromatography,and parts A and B containing acetophenones were obtained. Then,parts A and B were separated by HSCCC with a two-phase solvent system composed of petroleum ether-ethyl acetate-methanol-water( 4∶ 6∶ 4. 5∶ 5. 5 and4∶ 6 ∶ 3 ∶ 7, V/V), respectively. [Results] From 260 mg of part A, four compounds with p-dihydroxybenzene 3. 9 mg(Ⅰ),4-hydroxyacetophenone 17. 1 mg( Ⅱ),2,5-di-hydroxyacetophenone 13. 3 mg(Ⅲ) and 2,4-dihydroxyaceto-phenone 21. 0 mg(Ⅳ) were obtained. And from 300 mg of part B,136 mg of Radix Cynanchi Bungei benzophenone(Ⅴ) was obtained. The purity of compounds determined by HPLC was 97. 0%,96. 6%,99. 2%,99. 7%,99. 5%,respectively. [Conclusions] The established method is simple and efficient. It can be used for separation of acetophenones from Cynanchum bengei Decne root bark and has better practical value,which could provide a reference basis for development and utilization of Cynanchum bengei Decne root bark.

Comparison of Co-Current and Counter-Current Flow Fields on Extraction Performance in Micro-Channels

Several applications such as liquid-liquid extraction in micro-fluidic devices are concerned with the flow of two immiscible liquid phases. The commonly observed flow regimes in these systems are slug-flow and stratified flow. The latter regime in micro-channels has the inherent advantage that separation of the two liquids at the exit is efficient. Recently extraction in a stratified counter-current flow has been studied experimentally and it has been shown to be more efficient than co-current flow. An analytical as well as a numerical method to determine the steady-state solution of the corresponding convection-diffusion equation for the two flow-fields is presented. It is shown that the counter-current process is superior to the co-current process for the same set of parameters and operating conditions. A simplified model is proposed to analyse the process when diffusion in the transverse direction is not rate limiting. Different approaches to determining mass transfer coefficient are compared. The concept of log mean temperature difference used in design of heat exchangers is extended to describe mass transfer in the system.

The spatio-temporal variation of wintertime subtidal currents in the western Taiwan Strait

A new data set of observations by six cruises of ship-mounted acoustic doppler current profiler（SADCP） and three 40 d long bottom-mounted ADCPs（BADCPs） is employed to reveal the spatiotemporal variability of tidal and subtidal currents in the western Taiwan Strait（TWS） during winter season. The results confirm the existence of intense cotidal lines for M2 tidal current, which is located north of 25°N. In this case, no existence of an amphidromic point can be identified. It is also revealed that the counter-wind current（CWC） can extend through the whole western TWS and even occupy the entire water column during winter monsoon relaxation. However,this CWC is observed to be thoroughly overwhelmed by the downwind China coastal current（CCC） during the two big monsoon bloom events in the winter of 2007, and the CCC consequently extends southward throughout the western TWS instead. Most importantly, the variation of the spatial extent for the CWC and the CCC in the western TWS is found to be well explained by the first two modes of the vector empirical orthogonal function（VEOF） analysis, that is, it is mainly controlled by a wind-driven quasi barotropic current as the first mode and slightly modulated by a relatively weak background current with a first-order baroclinic structure as the second mode.

活性引导结合高速逆流色谱分离蓝莓活性成分及其与α-葡萄糖苷酶的相互作用

基于活性引导结合高速逆流色谱(HSCCC)技术,分离蓝莓中具有抑制α-葡萄糖苷酶活性的组分。首先,经不同溶剂提取后,活性成分在水中得到富集;其次,通过HSCCC分离水提物,得到6种组分,其中F4对α-葡萄糖苷酶的抑制率显著高于其它几种;再次将F4采用Sephadex LH-20葡聚糖凝胶纯化,得到高纯的组分Ⅰ;最后通过紫外光谱、傅里叶红外光谱、高效液相色谱-质谱联用及核磁技术鉴定组分Ⅰ为矢车菊-3-O-葡萄糖苷(C3G),纯度为95.06%。此外,采用多光谱扫描和分子对接技术对C3G与α-葡萄糖苷酶的相互作用进行表征。研究发现C3G与α-葡萄糖苷酶通过氢键自发结合形成复合物。与C3G复合后,α-葡萄糖苷酶的二级结构发生不同程度的变化,其中α-螺旋和β-转角降低,β-折叠和不规则卷曲增加。分子对接模拟发现C3G与残基Leu 313、Ser 157、Tyr 158、Phe 314、Arg 315和Asp 307以氢键结合,并与周围4个疏水残基存在疏水作用,共同维持复合物结构。本研究结果对开发2型糖尿病功能性食品具有重要意义。

Effects of WIN 55,212-2 on I_K Current in Cultured Trigeminal Ganglion Neurons of Rat

Summary: To investigate the effects of WIN 55,212-2 on I K in cultured rat trigeminal ganglion (TG) neurons, whole-cell patch clamp techniques were used to record the I K before and after WIN 55,212-2 perfusion at different concentrations. 30 μmol/L WIN 55,212-2 markedly (35 7 %± 7 3 %, P<0.01, n=8) inhibited I K currents, and the currents were partially recovered after washing. 30 μmol/L WIN 55,212-2 also induced a significant depolarizing shift in conductance-voltage parameters (control: V 0 5=10 43 ± 4.25 mV, k=16 27±3 86; WIN 55,212-2: V 0.5=24.71±3.91 mV, k =16.69±2.75; n = 8, P<0.01 for V 0.5). 0.01 μmol/L WIN 55,212-2 slightly (27.0 %± 7.9 %, P<0.05, n=7) increased I K currents, but had no significant change in conductance–voltage parameters (control: V 0.5=10.74±5.27 mV, k=17.33±2.96; WIN 55,212-2: V 0.5=11.06±2.05 mV, k=19.69±6.60; n=7, P>0.05 for V 0.5 and k). These results suggested that WIN 55,212-2 has dual action, which might be through different receptors.

A, ■-Ω METHOD FOR 3-D EDDY CURRENT ANALYSIS

After the field equations and the snonumuoo conditions between the interfaces for 3D eddy current problems Under various gauges were discussed, it was pointed cut in this paper that using the magnetic vector potential A. the electric scalar potential and Coulomb gauge △ .A = 0 in eddy current regions and using the magntetic scalar potential Ω in the non-conducting regions are more suitable. All field equations, the boundary conditions, the interface continuity conditions and the corresponding variational principle of this method are also given

EFFECTS OF THE HOE 694 ON TRANSIENT INWARD CURRENT AND NA^+- CA^(2+) EXCHANGE IN GUINEA PIG CARDIOMYOCYTES

To determine the effects of HOE 694, a new and potent Na＋- H＋ exchanger blocker, on transient inward current (Iti) and Na＋- Ca2＋ exchange during hypoxia- reoxygenation in guinea pig cardiomyocytes. Methods. Cardiomyocytes were isolated from adult guinea pig ventricle. Experiment was performed in an experimental chamber that allowed the cells to be exposed to a sufficiently low O2 pressure. The cells were subjected to hypoxia and reoxygenation. The ionic currents were studied with patch clamp technique. Results. In the absence of HOE 694, hypoxia- reoxygenation induced Iti in 12 of 15 experiments; but in cardiomyocytes pretreated with HOE 694 (10～ 50μ mol/L), the incidence of Iti observed during reoxygenation was reduced to 5 of 11 experiments and 3 of 10 experiments, P Conclusions. Blockade of the Na＋- H＋ exchange by HOE 694 could reduce Ca2＋ overload upon hypoxia- reoxygenation, and inhibition of Na＋- H＋ exchange may also indirectly decrease Na＋- Ca2＋ exchange activity during hypoxia.

Rapid and Continuous Extraction of Methyl Red from Wastewater Using Counter Current Chromatography

A new prototype and simple low speed counter current chromatography (LSCCC) has been fabricated and a laboratory work has been carried out for rapid and continuous removal of methyl red from wastewater using xylene as an extractant. The distribution ratio (D) and percentage of recoveries were calculated. The optimum concentration for extraction of methyl red was in the range of 2 × 10-4 to 8 × 10-4 mol·L-1. Maximum extraction achieved at pH range of 2 to 4.5. Various dye concentrations and solvent effects were studied to optimized conditions. It was shown that when the ratio of the organic phase to aqueous phase increased to more than 3:1, the striping efficiency decreased sharply. The experiments were carried out for 5 times and the highest extraction achieved was 99.8 per cent by two-solvent system LSCCC in just 5 minutes. Real wastewater samples were analyzed and the efficiency of the technique was compared with liquid-liquid extraction (LLE). In practice it was shown that although both techniques are rapid, the efficiency of the LSCCC is much better than LLE.

Exact Traveling Wave Solutions of Nano-Ionic Solitons and Nano-Ionic Current of MTs Using the exp(-φ (ξ ))-Expansion Method

In this work, the exp(-φ (ξ )) -expansion method is used for the first time to investigate the exact traveling wave solutions involving parameters of nonlinear evolution equations. When these parameters are taken to be special values, the solitary wave solutions are derived from the exact traveling wave solutions. The validity and reliability of the method are tested by its applications to Nano-ionic solitons wave’s propagation along microtubules in living cells and Nano-ionic currents of MTs which play an important role in biology.

Effects of Angiotensin Ⅱ and ACE Inhibitor,Captopril on L-type Calcium Current and Sodium Current of Single Guinea Myocytes

Objectives To investigate effect of Angll, captopril on single guinea myocytes on L - type calcium current and sodium current. Methods Membrane patch clamp whole cell recording technique was used to investigate effect of angll, captopril on L - Ca maximum current density and sodium maximum current density. Resutls Angll increased the maximum current density compared with control after perfused 5 min, 357. 7 ±219. 7 Vs 279. 5± 240. 5 PA/PF, increase rate is 27. 9 %, the shape of current - voltage relationship curve was unchanged, peaked at + 10 mv, indicated that angll increased L - Ca current density in voltage - dependent. After perfused with captopril, captopril + angll 3, 5 min, L - Ca current was recorded, results suggest L - Ca maximum current density decreased significantly compared with control, in captopril group, 128. 4 ± 92. 6Vs286. 2 ± 89. 7, 66. 7±68. 3Vs 286. 2 ± 89. 7, respectively, rate of inhibition is 55. 1 %, 76. 6 %, respectively. L - Ca current further decreased in captopril perfused 5 min compared with 3 min, 66. 7 ± 68. 3 Vs 128. 4 ± 92. 6, in captopril + angll group, L - Ca current decreased greatly in 3, 5 min than control, 143. 4±117. 6Vs 267. 7±141. 4, 96. 4±82. 5 Vs 267. 7±141. 4, respectively, rate of inhibition is 46. 4 % , 63. 9 % respectively. We also investigated effect of captopril on Na current, which decreased significantly in 1 min and 3 min compared with control, 939. 1 ±319. 1 Vs 1398. 0±144. 6 PA/PF, 469. 95 ± 314. 9 Vs 1398. 0 ±144. 6 PA/PF, respectively, rate of inhibition is 32. 8 % , 66. 3 % , respectively. Na current density decreased significantly in 3 min compared with 1 min, 469. 9±314. 9 Vs 939. 1±319. 1PA/PF, rate of inhibition is 49. 9 % . Conclusions Angiotensin Ⅱexerts increased maximum current density of L - Ca in voltage dependent, captopril decreased maximum current density of L - Ca in voltage dependent, decreased sodium maximum current density, which is the prominently antiarrhythmia mechanisms through inhibition of angiotensin Ⅱ evoked calcium dependent transient inward current and calcium overload.

蜘蛛网流道冷板冷却液对向流锂离子电池散热分析

锂离子电池工作温度过高或温差过大将导致其容量降低和寿命缩短。为了降低其工作温度及温差,设计了一款蜘蛛网流道冷板,采用数值方法对其冷却液对向流锂离子电池散热进行了计算。比较了蜘蛛网流道冷板冷却液对向流与同向流锂离子电池的散热情况,分析了冷却液流量以及冷板内流道夹角、槽深、壁厚对电池散热的影响。结果表明:与冷却液同向流电池相比,冷却液对向流电池最高温度、温差都降低,电池温度分布更加均匀。在0.02~0.06 kg/s区间,随着冷却液流量增大,电池最高温度和温差快速降低,而冷却液压降缓慢增大;当冷却液流量大于0.06 kg/s时,随着冷却液流量增大,电池最高温度和温差缓慢降低,而冷却液压降快速增大。增大流道夹角可使流道在冷板内分布更加均匀,提高冷板散热能力。当冷却液质量流量恒定时,增大流道槽深可使冷却液压降显著减小,但会引起电池最高温度和温差略微升高。随着流道壁厚增大,电池最高温度和温差均呈下降趋势。蜘蛛网流道冷板在流道夹角80°、槽深1 mm、壁厚2 mm、冷却液流量0.06 kg/s对向流冷却条件下,可使锂离子电池3C放电最高温度和温差降至31.02℃和4.54℃。

高速逆流色谱分离纯化防风中升麻素苷和5-O-甲基维斯阿米醇苷

建立了高速逆流色谱分离制备防风中有效成分升麻素苷和5-O-甲基维斯阿米醇苷的方法。防风根的粉末经甲醇浸泡提取和减压蒸馏,得粗提浸膏。以V(乙酸乙酯)∶V(正丁醇)∶V(水)=2∶7∶9为溶剂,上相为固定相,下相为流动相,流速2.0mL/min。从316mg防风粗提物中一步分离得到13.9mg升麻素苷和25mg5-O-甲基维斯阿米醇苷,纯度分别为98.1%和99.2%。采用ESI-MS,1H NMR和13C NMR对目标化合物的结构进行了鉴定。

薄层色谱-荧光法测定黄连生物碱分配系数

建立了薄层色谱和荧光分析法测定黄连生物碱在高速逆流色谱溶剂体系中分配系数的方法。样品在溶剂体系中分配平衡后,取等量的上下相,经点板、展开、刮板,提取后用荧光分光光度法检测样品的荧光值（激发波长365 nm,发射波长409 nm）,并计算样品在溶剂体系中的分配系数。在一定的浓度范围内,4种生物碱的含量与荧光强度呈良好的线性关系,加样回收率为94.7%~104.1%;相对标准偏差为1.9%~3.8%。本方法测定的分配系数与HPLC法无显著性差异。本方法准确度高,耗时少,应用范围广。

微涡旋絮凝-逆流气浮-纳滤集成工艺去除水中腐殖酸的研究之二——以聚合氯化铁(PFC)为絮凝剂

试验研究了微涡旋絮凝-逆流气浮-纳滤集成工艺去除水中腐殖酸的工艺特征和效果.试验结果表明,微涡旋絮凝-逆流气浮工艺去除水中腐殖酸时,在聚合氯化铁（PFC）的最佳投药点0.62 mmol·L^-1（Fe^3＋）下,出水水质符合纳滤膜系统预处理单元的要求,而且该工艺需要PFC絮凝剂的量较低.该预处理系统与纳滤系统组合的集成工艺可以使水中的腐殖酸有机物浓度大大降低,且含TQ56-36FC型纳滤膜的流程1比含M-N1812A型纳滤膜的流程2效果好.前者出水的TOC值可达0.48 mg·L^-1,CODMn值为0.64～0.69mg·L^-1,UV254值为0,且有95%以上的脱盐率.后者出水的TOC值为0.61～1.00mg·L^-1,CODMn值为0.72～0.97mg·L^-1,UV254值为0～0.0109,脱盐率很低.另外,尽管保安过滤/活性炭预处理有利于纳滤膜出水水质的提高,但活性炭柱的存在也降低了纳滤膜对有机物的去除率.动态实验结果表明,该集成工艺在本试验中运行周期为72h.水中颗粒物粒度分布表明,原水、絮凝后和气浮出水中颗粒物粒度分布的中位直径（d50）分别为2～5 μm、21 μm和16μm;经过保安过滤器或保安过滤器/活性炭柱,水样中的颗粒物的d50为0到几个μm;经过纳滤膜后,出水基本无颗粒物.初步研究表明,微涡旋絮凝过程中投药量对絮体的分形维数有着显著影响.

钾长石-石膏-碳酸钙热分解烧成物中硫酸钾的浸取过程

采用多级逆流浸取操作方式以提高钾长石热分解烧成物浸取液中硫酸钾的浓度和浸出率，在对浸取过程进行分析和合理假设的基础上对过程进行了数学描述，建立了浸取过程相应参数的计算式。实验表明浸取液中硫酸钾浓度、液相量、固相量等的测量值与计算值相符合，说明浸取过程的数学描述合理，能以此设计浸取过程和预测相应的过程参数。

超临界CO_2萃取-高速逆流色谱分离纯化丹皮中丹皮酚

采用超临界CO2提取中药丹皮中总丹皮酚,选择萃取温度、萃取压力、物料粒度为因素进行正交实验优选出超临界CO2萃取的最佳工艺条件:即物料粒度40～60目,萃取温度40℃,萃取压力20MPa,提取率可达90%以上。将萃取后的总丹皮酚应用高速逆流色谱进行分离纯化,两相溶剂系统为石油醚-乙酸乙酯-甲醇-水(1:0.4:1:0.4),进样量为330mg,得180mg纯度为99.0%的丹皮酚。