Omnipaque脊髓造影的初步体会

Omnipaque是新型非离子化水溶性造影剂（1），又名Iohexel,三碘三酰苯，碘酞六醇和通用泛影酰苯，自1982年问世以来，文献报道（1－2），它不仅是各种血管造影的优良造影剂，而且也是脊髓造影的首选造影剂，我院自1986年9月至1988年5月共做了Omnipaque脊髓造影40例，现将初步体会报道于后。

电磁波的危害是否存在?

电磁波到底会不会导致癌症、头痛、失眠和其他疾病?最近的研究结果表明不会,但争论仍在继续。

Efficient and stable Ru(Ⅲ)-choline chloride catalyst system with low Ru content for non-mercury acetylene hydrochlorination

Herein,we report an excellent,supported Ru(III)‐ChCl/AC catalyst with lower Ru content,where the ionic complex ChRuCl4 serves as the active component for acetylene hydrochlorination.The prepared heterogeneous Ru‐10%ChCl/AC catalyst shows excellent activity and long‐term stability.In this system,ChCl provides an environment for the ChRuCl4 to be stabilized as Ru(III),thus suppressing the reduction of the active species and the aggregation of ruthenium species during the reaction.The interaction between reactants and catalyst species was investigated by catalyst characterizations in combination with DFT calculations to disclose the effect of the ChRuCl4 complex and ChCl on the catalytic performance.This inexpensive,efficient,and long‐term catalyst is a competitive candidate for application in the hydrochlorination industry.

Polyethoxylation and polypropoxylation reactions：Kinetics,mass transfer and industrial reactor design

Ethoxylation and propoxylation reactions are performed in the industry to produce mainly non-ionic surfactants and ethylene oxide(EO)–propylene oxide(PO) copolymers.Both the reactions occur in gas–liquid reactors by feeding gaseous EO,PO or both into the reactor containing a solution of an alkaline catalyst(KOH or Na OH).Non-ionic surfactants are produced by using liquid starters like fatty alcohols,fatty acids or alkyl-phenols,while when the scope is to prepare EO–PO copolymers the starter can be a mono-or multi-functional alcohol of low molecular weight.Both reactions are strongly exothermic,and EO and PO,in some conditions,can give place to runaway and also to explosive side reactions.Therefore,the choice of a suitable reactor is a key factor for operating in safe conditions.A correct reactor design requires:(i) the knowledge of the kinetic laws governing the rates of the occurring reactions;(ii) the role of mass and heat transfer in affecting the reaction rate;(iii) the solubility of EO and PO in the reacting mixture with the non-ideality of the reacting solutions considered;(iv) the density of the reacting mixture.All these aspects have been studied by our research group for different starters of industrial interest,and the data collected by using semibatch well stirred laboratory reactors have been employed for the simulation of industrial reactors,in particular Gas–Liquid Spray Tower Loop Reactors.

Relationship Between Iron Oxides and Surface Charge Characteristics in Soils

The relationship between iron oxides and surface charge characteristics in variable charge soils ( latosol and red earth ) was studied in following three ways. ( 1 ) Remove free iron oxides ( Fed ) and amorphous iron oxides ( Feo ) from the soils with sodium dithionite and acid ammonium oxalate solution respectively. ( 2 ) Add 2% glucose ( on the basis of air-dry soil weight ) to soils and incubate under submerged condition to activate iron oxides, and then the mixtures are dehydrated and air-dried to age iron oxides. ( 3 ) Precipitate various crystalline forms of iron oxides onto kaolinite. The results showed that free iron oxides ( Fed ) were the chief carrier of variable positive charges. Of which crystalline iron oxides ( Fed-Feo ) presented mainly as discrete particles in the soils and could only play a role of the carrier of positive charges, and did little influence on negative charges. Whereas the amorphous iron oxides ( Feo ) , which presented mainly as a coating with a large specific surface area, not only had positive charges, but also blocked the negative charge sites in soils. Submerged incubation activated iron oxides in the soils, and increased the amount of amorphous iron oxides and the degree of activation of iron oxide, which resulted in the increase of positive and negative charges of soils. Dehydration and air-dry aged iron oxides in soils and decreased the amount of amorphous iron oxides and the degree of activation of iron oxide, and also led to the decrease of positive and negative charges. Both the submerged incubation and the dehydration and air-dry had no significant influence on net charges. Precipitation of iron oxides onto kaolinite markedly increased positive charges and decreased negative charges. Amorphous iron oxide having a larger surface area contributed more positive charge sites and blocked more negative charge sites in kaolinite than crystalline goethite.

Identification of TRPM7 channels in human intestinal interstitial cells of Cajal

AIM： To investigate the characteristics of slow electrical waves and the presence of transient receptor potential melastatin-type 7 （TRPM7） in the human gastrointestinal （GI） tract. METHODS： Conventional microelectrode techniques were used to record intracellular electrical responses from human GI smooth muscle tissue. Immunohistochemistry was used to identify TRPM7 channels in interstitial cells of Cajat （ICCs）. RESULTS： The human GI tract generated slow electrical waves and had ICCs which functioned as pacemak er cells. Flufenamic acid, a nonselective cation channel blocker, and 2-APB （2-aminoethoxydiphenyl borate） and La3＋, TRPM7 channel blockers, inhibited the slowwaves. Also, TRPM7 channels were expressed in ICCs in human tissue. CONCLUSION： These results suggest that the human GI tract generates slow waves and that TRPM7 channels expressed in the ICCs may be involved in the gen- eration of the slow waves.

Synthesis of 4,4＇-MDC in the Presence of Sulfonic Acid-functionalized Ionic Liquids

The synthesis of methylene diphenyl dimethylcarbamate （4,4＇-MDC） from methyl N-phenyl carbonate （MPC） and formaldehyde （HCHO） was conducted in the presence of sulfonic acid-functionalized ionic liquids （ILs） as dual solvent-catalyst. The influences of the kind of anion in the ionic liquids, reaction conditions and the recycle of the ionic liquid on 4,4＇-MDC synthesis reaction were investigated. In addition, the acid strength of ILs was de-termined by the Hammett method with UV-visible spectroscopy, and the acid strength-catalytic activity relationship was correlated. The activity estimation results showed that [HSO3-bmim]CF3SO3 was the optimal dual solvent-catalyst. Under the suitable reaction conditions of 70℃, 40 min, molar ratio of nMPC/nHCHO= 10/1 and mass ratio of WILs/WMPC = 4.5/1, the yield of 4,4＇-MDC based on HCHO was 89.9 % and the selectivity of 4,4＇-MDC with respect to MPC was 74.9%. Besides, [HSO3-bmim]CF3SO3 was reused four times after being purified and no significant loss in the catalytic activity was observed.

Dust Acoustic Solitary Waves in Saturn F-ring's Region

Effect of hot and cold dust charge on the propagation of dust-acoustic waves （DAWs） in unmagnetized plasma having electrons, singly charged ions, hot and cold dust grains has been investigated. The reductive perturbation method is employed to reduce the basic set of fluid equations to the Kortewege-de Vries （KdV） equation. At the critical hot dusty plasma density Nho, the KdV equation is not appropriate for describing the system. Hence, a set of stretched coordinates is considered to derive the modified KdV equation. It is found that the presence of hot and cold dust charge grains not only significantly modifies the basic properties of solitary structure, but also changes the polarity of the solitary profiles. In the vicinity of the critical hot dusty plasma density Nho, neither KdV nor mKdV equation is appropriate for describing the DAWs. Therefore, a further modified KdV （fmKdV） equation is derived, which admits both soliton and double layer solutions.

Pulsed Corona Discharges and Their Applications in Toxic VOCs Abatement

Plasma processes are among the emerging technologies for volatile organic compounds (VOCs) abatement[1]. Both thermal plasmas and non-equilibrium plasmas (cold plasmas) are being developed for VOCs cleanup[2,3]. Particularly, pulsed corona discharges offer several advantages over conventional VOCs abatement techniques[4-7]. To optimize the existing technology and to develop it further, there is need to understand the mechanisms involved in plasma chemical reactions. Furthermore, it is strongly desirable to be able to predict the behavior of new VOCs in non-equilibrium plasma environment from the data known for a few representative compounds. Pulsed corona discharge technique is introduced here with citation of relevant literature. Fundamental principles, useful for predicting the VOCs' decomposition behavior, have been worked out from the published literature. Latest developments in the area, targeted to minimize the energy losses, improve the VOCs destruction efficiency and reduce the generation of unwanted organic and inorganic by-products, are presented.

Effects of Ionic Concentrations on Survival and Growth in Polyculture of Litopenaeus vannamei with Oreochromis niloticus in Low Salinity Water

A study comparative of rearing of the Pacific white shrimp （Litopenaeus vannamei） with the Nile tilapia （Oreochromis niloticus） in three earthen ponds （5,600 m^2） with the salinity ranged from 0.5-1.2 ppt and three treatment ponds with salinity of 2-4 ppt by adding brine water into the ponds. Postlarvae 12 （PL12） of L. vannamei were stocked at density of 9 PL/m^2 and after one week the Nile tilapia fingerlings were stocked at density of I fish/m^2. Only pelleted feed were given to the fish during the 196-day rearing period. Shrimps were partially harvested by sieve net at day 80 and 120, and five days later PLI2 were stocked at the rate of 3 PL/m^2. After final harvesting at day 196, the production, body weight and survival from the treatment group were significantly higher （P 〈 0.05） than those of the control group. While the fish production body weight and survival rate from both groups were not significant differences （P 〉 0.051）. The ionic concentration of six major ions （CI, SO42, Ca^2＋, Na^＋, Mg^2＋ and K^＋）, salinity and hardness in the treatment ponds were significantly higher than those of the control ponds （P 〈 0.05）. Moreover, the ionic profiles of the treatment ponds were similar to seawater at the salinity of 2 ppt while only 1 ppt in the control ponds. Results from the study indicated that in order to achieve good growth and survival rate of L. vannamei, brine water should be added into grow-out ponds prior to stocking and during the rearing： period to obtain and maintain the salinity not less than 2 ppt.

The Velocity Measurement of Two-phase Flow Based on Particle Swarm Optimization Algorithm and Nonlinear Blind Source Separation

In order to overcome the disturbance of noise,this paper presented a method to measure two-phase flow velocity using particle swarm optimization algorithm,nonlinear blind source separation and cross correlation method.Because of the nonlinear relationship between the output signals of capacitance sensors and fluid in pipeline,nonlinear blind source separation is applied.In nonlinear blind source separation,the odd polynomials of higher order are used to fit the nonlinear transformation function,and the mutual information of separation signals is used as the evaluation function.Then the parameters of polynomial and linear separation matrix can be estimated by mutual information of separation signals and particle swarm optimization algorithm,thus the source signals can be separated from the mixed signals.The two-phase flow signals with noise which are obtained from upstream and downstream sensors are respectively processed by nonlinear blind source separation method so that the noise can be effectively removed.Therefore,based on these noise-suppressed signals,the distinct curves of cross correlation function and the transit times are obtained,and then the velocities of two-phase flow can be accurately calculated.Finally,the simulation experimental results are given.The results have proved that this method can meet the measurement requirements of two-phase flow velocity.

Research on solubilization used for micellar enhanced ultrafiltration

Micellar enhanced ultrafiltration （MEUF） is a new effective treatment technology for the filtration removal of organic pollutants through solubilization. The present paper is aimed to study the solubilization of organic compounds such as chlorobenzene （CB）, pyrene and phenol by anionic, cationic and mixed anionic-nonionic surfactants such as sodium dodecyl sulfate （SDS）, cetyltrimethylammonium bromide （CTMAB） and Tween-80 （TW80） and the mixed SDS-TW80 with a batch equilibrium method. This study enables us to supply deeper investigation for MEUF. The results showed that solubilization capacity was not obvious below the critical micellar concentration （CMC）. The apparent solubilities of organic compounds were linearly related to surfactant concentrations over their CMCs. Solubilization capacity by single surfactants follow the order of TW80 〉 CTMAB 〉 SDS. The results also proved that the solubilization of the organic contaminants by the mixed surfactants can significantly be enhanced compared with the single anionic surfactant SDS. Whereas the CMC can be decreased, the solubility can be increased as long as the mass ratio of nonionic surfactant increases. The solubility enhancement efficiency of the different organic compounds follow the order of phenol 〉 CB 〉 pyrene. In addition, the solubilization ratio appears to be positively relative to the intrinsic water solubility of the organic contaminants and negatively correlates to octanol-water coefficients （Kow） of organic compounds and the hydrophile-lypophile balance values （HLB） of the surfactants.

A Theoretic Model for the Shock Observed in Geo-space

An electrostatic model for the shock observed in the earth's polar region is established by deriving the 'Sagdeev potential' from the magnetohydrodynamic equations in a cylindrical coordinate system. The results show that the shock can develop from the ion acoustic wave or ion cyclotron wave in the polar region, and can exist when the Mach number M and the initial electric field E-0 satisfy the condition of vertical bar(a/M-2-1)E(0)vertical bar = 1. Also, some features of the shock wave are discussed. The result can interpret the electrostatic shock observed in the earth's polar region.

Effect of Polynomial Expressed Distribution Dust Particles for Unmagnetized Two-Ion-Temperature Dusty Plasma

Linear dispersion relation for linear wave and a Kadomtsev-Petviashvili (KP) equation for nonlinearwave are given for the unmagnetized two-ion-temperature cold dusty plasma with many different dust grain species.The numerical results of variations of linear dispersion with respect to the different dust size distribution are given.Moreover,how the amplitude,width,and propagation velocity of solitary wave vary vs different dust size distribution isalso studied numerically in this paper.

A Simple Determination of Polyethylene Oxide-type Non-ionic Surfactant by Adhesion Method

A simple and rapid method for the determination of polyethylene oxide-type non-ionic surfactants is reported herein. This method is based on the adhesion of calcium/non-ionic surfactant complexes with tetra phenyl porphine sulfonic acid （TPPS） to the wall of reaction vessel upon vigorous shaking. The ion-associate adhering to the inner wall of the vessel was dissolved with water after discarding the solution and spectrophotometrically assayed at 412 nm. From the standard curve for Triton X-100, the order of the sensitivity for different ions was as follows： Ca^2＋〉 K^＋〉 NH4^＋〉 Ba^2＋. The proposed method does not involve extraction of the ion-associated with harmful solvents and can be simply performed by combining a procedure based on hand shaking and the use of a spectrophotometer.

The Effect of the Under-dense Magnetized Plasma on Electron Density Distribution and Field Profile

Propagation of a high frequency electromagnetic wave in under-dence plasma in presence of an external magnetic field is investigated. When a constant magnetic field perpendicular to the motion of electrons is applied, then the electrons rotate around the magnetic field lines and generate electromagnetic part in the wake with a nonzero group velocity. Using of the Maxwell equations and nonlinear differential equation for the electric field a direct one dimensional （ID） procedure for calculating wake equations are developed and the electric and magnetic field profile in the plasma are investigated.

磁共振成像造影剂的研究进展

磁共振成像是20世纪80年代发展起来的一项先进医学影像诊断技术, 目前已广泛用于临床诊断, 其中30%以上的成像诊断须用磁共振成像造影剂. 介绍了磁共振成像造影剂的定义和分类, 以及顺磁性造影剂的一些研究进展. 详细讨论了水溶性顺磁性造影剂的非离子化、靶向性和大分子化3个发展方向, 提出了磁共振成像造影剂今后研究与开发中应注意的一些问题和发展趋势.

整形美容外科基本知识试题及解答

1局部麻醉药中为什么有时加入碳酸氢钠？答：局部麻醉液是离子化和非离子化形式的平衡液。非离子化形式能更快地进入神经组织。使溶液碱化并改变非离子化形式的浓度，从而增加局部麻醉药的起效速度和效力。合理的剂量为10ml利多卡因加入1mEq的碳酸氢钠，20ml布比卡因加入0．1mEq的碳酸氢钠。

产后抑郁,如何安全用药?

“有的年轻妈妈被诊断为产后抑郁症后，因为病情原因需要服药，但又担心会影响吃母乳的宝宝，所以内心非常纠结。”问题1：服药能够哺乳吗？尽管有充足的依据支持母乳喂养的益处，然而母亲血浆中的抗抑郁剂是否会通过母乳而殃及婴儿，目前还没有足够依据加以排除。经研究，分子量〈200、非离子化程度高、脂溶性高及弱碱性药物较易扩散到母乳中。由于缺乏安全性资料，许多母亲不愿在抗抑郁剂治疗时同时哺乳。