Prescription for optimizing holograms in LiNbO3 : Fe : Mn

The photorefractive holographic dynamics of grating formation in photochromic doubly doped LiNbO3:Fe:Mn crystal is studied numerically and analytically in terms of the two-center model of Kukhtarev Et al. [Ferroelectrics 22, 949 (1979)]. The relations among the recorded and fixed space-charge fields and the doping densities, the oxidation-reduction states of the fields, and the intensities of UV-sensitizing and red recording beams are studied. Important conditions and effects are feued, and an optimal prescription for material doping and oxidation-reduction processing is suggested in which the crystal can be strongly oxidized and the Mn-doping density is smaller than the Fe-doping density. (C) 2000 Optical Society of America. OCIS codes: 050.7330, 190.5330, 090.2900.

New antibiotic with typical plant anthraquinone structure obtained studying terrestrial and marine Streptomycetes

In our screening for new antibiotics from bacteria, the streptomycete isolate M097 from Jiaozhou Bay in China was found to produce aloesaponarin II (1a) and 1,6-dihydroxy-8-hydroxymethyl-anthraquinone (2). Similarly, a terrestrial streptomycete GW24/1694 produced 1a and its methyl ether, the new compound 1-hydroxy-6-methoxy-8-methyl-anthraquinone (1b). All structures were derived by spectrochemical analysis and by comparison with reference data. The results showed that the marine streptomycete isolate M097 and the terrestrial streptomycete GW24/1694 could be a promising material for studying the biosynthetic pathway of polyketides.

Concurrence of cat and tet genes in multiple antibiotic-resistant bacteria isolated from a sea cucumber and sea urchin mariculture farm in China

A basic understanding of abundance and diversity of antibiotic-resistant microbes and their genetic determinants is necessary for finding a way to prevent and control the spread of antibiotic resistance. For this purpose, chloramphenicol and multiple antibiotic-resistant bacteria were screened from a mariculture farm in northern China. Both sea cucumber and sea urchin rearing ponds were populated with abundant antibiotic-resistant bacteria, especially marine vibrios. Sixty-five percent chloramphenicol-resistant isolates from sea cucumber harbored a cat gene, either cat IV or cat II, whereas 35% sea urchin isolates harbored a cat gene, actually cat II. The predominant resistance determinant cat IV gene mainly occurred in isolates related to Vibrio tasmaniensis or Pseudoalteromonas atlantica, and the cat II gene mainly occurred in Vibrio splendidus-like isolates. All the cat-positive isolates also harbored one or two of the tet genes, tet(D), tet(B), or tet(A). As no chloramphenicol-related antibiotic was ever used, coselection of the cat genes by other antibiotics, especially oxytetracycline, might be the cause of the high incidence of cat genes in the mariculture farm studied.

New method for analysis of Chinese herbal complex prescription and its application

Traditional Chinese medicine (TCM) is a great treasure of China, the analysis of which is an arduous task. The viewpoint that all chemical constituents of Chinese herbal complex prescription should be analyzed as a black box is elucidated for the first time. Intelligent multi-mode multi-column chromatographic system (IMMCC) with its hybrids is the basic method and HPLC Unified Method is the breakthrough for the black box analysis. Dang-Gui-Bu-Xue-Tang was selected as a typical TCM and a systematic separation method from non-aqueous mobile phase to pure water mobile phase was put forward in order to convert unknown sample to known sample. The a, c values and UV spectra of 66 components of Astragalus, 78 components of Angelica and 71 components of Dang-Gui-Bu-Xue-Tang were obtained. Intelligent optimization and peak identification method and software for complex samples were developed and the optimum multi-step multi-binary gradient curve of mobile phase for Astragalus was ascertained. The maximum error and minimum error of predicted retention time for all components of Astragalus are 8.62% and 0.05% respectively. All components of Astragalus were compared with those of Angelica and it is found that many components of Astragalus are the same as those of Angelica, while the contents of these components are different. Many components of Dang-Gui-Bu-Xue-Tang are also the same as those of Astragalus and Angelica with different contents.

Separation of compounds interacting with liposome membrane in combined prescription of traditional Chinese medicines with immobilized liposome chromatography

Immobilized liposome chromatography (ILC), the stationary phase of which has been regarded as a mimic biomembranes system was used to separate and analyze compounds interacting with liposome membrane in Danggui Buxue decoction, a combined prescription of traditional Chinese medicines (CPTCMs), and its compositions Radix Astragli and Radix Angelica Sinensis. More than 10 main peaks in the extract of Danggui Buxue decoction were resolved on the ILC column, suggesting that more than 10 components in the prescription have significant retention on ILC column. Ligustilide, astragaloside, TV and formononetin, three main bioactive ingredients in Danggui Buxue decoction, were found to have relatively significant, while ferulic acid, another bioactive ingredient in the prescription, relatively weak retention on ILC column. Effects of the eluent pH and amount of immobilized phosphatidylcholine (PC) on separation of interactional compounds in the extract of Danggui Buxue decoction were also investigated. It was found that these two factors strongly affected the retention of some interactional compounds. In addition, the fractions partitioned with different solvents from water extract of this combined prescription were evaluated with this ILC column system. (c) 2005 Elsevier B.V. All rights reserved.

Subgrid scale fluid velocity timescales seen by inertial particles in large-eddy simulation of particle-laden turbulence

Large-eddy simulation (LES) has emerged as a promising tool for simulating turbulent flows in general and, in recent years,has also been applied to the particle-laden turbulence with some success (Kassinos et al., 2007). The motion of inertial particles is much more complicated than fluid elements, and therefore, LES of turbulent flow laden with inertial particles encounters new challenges. In the conventional LES, only large-scale eddies are explicitly resolved and the effects of unresolved, small or subgrid scale (SGS) eddies on the large-scale eddies are modeled. The SGS turbulent flow field is not available. The effects of SGS turbulent velocity field on particle motion have been studied by Wang and Squires (1996), Armenio et al. (1999), Yamamoto et al. (2001), Shotorban and Mashayek (2006a,b), Fede and Simonin (2006), Berrouk et al. (2007), Bini and Jones (2008), and Pozorski and Apte (2009), amongst others. One contemporary method to include the effects of SGS eddies on inertial particle motions is to introduce a stochastic differential equation (SDE), that is, a Langevin stochastic equation to model the SGS fluid velocity seen by inertial particles (Fede et al., 2006; Shotorban and Mashayek, 2006a; Shotorban and Mashayek, 2006b; Berrouk et al., 2007; Bini and Jones, 2008; Pozorski and Apte, 2009).However, the accuracy of such a Langevin equation model depends primarily on the prescription of the SGS fluid velocity autocorrelation time seen by an inertial particle or the inertial particle–SGS eddy interaction timescale (denoted by $\delt T_{Lp}$ and a second model constant in the diffusion term which controls the intensity of the random force received by an inertial particle (denoted by C_0, see Eq. (7)). From the theoretical point of view, dTLp differs significantly from the Lagrangian fluid velocity correlation time (Reeks, 1977; Wang and Stock, 1993), and this carries the essential nonlinearity in the statistical modeling of particle motion. dTLp and C0 may depend on the filter width and particle Stokes number even for a given turbulent flow. In previous studies, dTLp is modeled either by the fluid SGS Lagrangian timescale (Fede et al., 2006; Shotorban and Mashayek, 2006b; Pozorski and Apte, 2009; Bini and Jones, 2008) or by a simple extension of the timescale obtained from the full flow field (Berrouk et al., 2007). In this work, we shall study the subtle and on-monotonic dependence of $\delt T_{Lp}$ on the filter width and particle Stokes number using a flow field obtained from Direct Numerical Simulation (DNS). We then propose an empirical closure model for $\delta T_{Lp}$. Finally, the model is validated against LES of particle-laden turbulence in predicting single-particle statistics such as particle kinetic energy. As a first step, we consider the particle motion under the one-way coupling assumption in isotropic turbulent flow and neglect the gravitational settling effect. The one-way coupling assumption is only valid for low particle mass loading.

Nonvolatile photorefractive holograms in LiNbO3 : Cu : Ce crystals

We report experimental and theoretical studies of nonvolatile photorefractive holographic recording in LiNbO3:Cu:Ce crystals with two illumination schemes: (1) UV light for sensitization and a red interfering pattern for recording and (2) blue light for sensitization and a red pattern for recording. The results show that the oxidized LiNbO3:Cu:Ce crystals can provide high, persistent refractive-index modulation with weak lightinduced scattering. The optimal working conditions and the prescription for doping and oxidation-reduction processing that yields the maximum refractive-index modulation are discussed. (C) 2000 Optical Society of America OCIS codes: 050.7330, 190.5330, 090.2900.

Optimal recording wavelength for nonvolatile photorefractive holograms in Ce : Cu : LiNbO

Three wavelengths of red, green and blue of recording beams are systemically tested for the UV-assistant recording and optical fixing of holograms in a strongly oxidized Ce:Cu:LiNbO3 crystal. Three different photorefractive phenomena are observed. It is shown that the green beams will optimally generate a critical strong nonvolatile hologram with quick sensitivity and the optimal switching technique could be jointly used to obtain a nearly 100% high diffraction. Theoretical verification is given, and a prescription on the doping densities and on the oxidation/reduction states of the material to match a defined recording wavelength for high diffraction is suggested.

Maximins S, a novel group of antimicrobial peptides from toad Bombina maxima

Amphibian skin secretions are rich in antimicrobial peptides acting as important components of innate defense system against invading microorganisms. A novel type of peptide, designated as maximin S, was deduced by random sequencing of 793 clones from a constructed Bombina maxima skin cDNA library. The putative primary structures of maximin S peptides can be grouped into five species, in which maximin S I has 14 amino acid residues and the rest of maximin S peptides (S2-S5) all have 18 amino acid residues. Unlike most of the amphibian antimicrobial peptides so far identified, the newly characterized four maximin S precursors are composed of maximin S I and different combinations of tandem repeated maximin S2-S5 linked by internal peptides. Except maximin S I, the predicted secondary structures of maximin S2-S5 show a similar amphipathic alpha-helical structure. MALDI-TOF mass spectrometry analysis of partially isolated skin secretions of the toad indicates that most of the deduced maximin S peptides are expressed. Two deduced maximin S peptides (S1, S4) were synthesized and their antimicrobial activities were tested. Maximin S4 only had an antibiotic activity against mycoplasma and had no antibacterial or antifungal activity toward tested strains. Maximin S1 had no activity under the same conditions. (C) 2004 Elsevier Inc. All rights reserved.

Effect of antibiotics on development in vitro of hamster pronucleate ova

Antibiotics are commonly added to embryo culture media, but effects on embryo development have not been examined thoroughly. Hamster ova were used to investigate whether penicillin, streptomycin or gentamicin affect embryo development in vitro. Ova were collected 10 h post activation by spermatozoa in vivo and cultured in five treatments: 1) Control: chemically-defined medium HECM-9 with no antibiotics; 2) HECM-9 with 100 IU/mL, penicillin; 3) HECM-9 with 50 mug/mL streptomycin; 4) HECM-9 with 10 mug/mL,gentamicin and 5) HECM-9 with both 100 IU/mL penicillin and 50 mug/mL streptomycin. Individually, penicillin, streptomycin and gentamicin did not affect embryo development to the 8-cell stage at 58 h post oocyte activation, or morula/blastocyst stages, or blastocysts alone at 82 h post activation. However, when penicillin and streptomycin were both present in the culture medium the percentages of 8-cell embryos at 58 h and blastocysts at 82 h were significantly lower than the control. No antibiotic treatment improved hamster embryo development in vitro. We caution against the use of penicillin and streptomycin together for hamster embryo culture, and show that it is not necessary to include any antibiotics in embryo culture media for up to 72 h if proper sterile technique is used with an oil overlay. (C) 2000 by Elsevier Science Inc.

A TPR-family membrane protein gene is required for light-activated heterotrophic growth of the cyanobacterium Synechocystis sp PCC 6803

The unicellular cyanobacterium Synechocystis sp. PCC6803 can grow heterotrophically in complete darkness, given that a brief period of illumination is supplemented every day (light-activated heterotrophic growth, LAHG), or under very weak ( < 0.5 mumol m(-2) s(-1)) but continuous light. By random insertion of the genome with an antibiotic resistance cassette, mutants defective in LAHG were generated. In two identical mutants, sll0886, a tetratricopeptide repeat (TPR)-family membrane protein gene, was disrupted. Targeted insertion of sll0886 and three downstream genes showed that the phenotype was not due to a polar effect. The sll0886 mutant shows normal photoheterotrophic growth when the light intensity is at 2.5 mumol m(-2) s(-1) or above, but no growth at 0.5 mumol m(-2) s(-1). Homologs to sll0886 are also present in cyanobacteria that are not known of LAHG. sll0886 and homologs may be involved in controlling different physiological processes that respond to light of low fluence. (C) 2003 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.

中药处方配伍监控系统的设计与实现

医院信息系统(hospital information system,HIS)作为医院信息化建设的重要组成部分越来越受到社会的重视,已经进入一个高速发展的阶段。但是作为诊疗过程的一个重要组成部分-药物处方治疗,在HIS中却缺少必要的监控与指导。在HIS标准化推进的同时,更应该对其深度和广度进行研究,结合软件工程的设计思想,基于面向对象的开发方法,设计开发了“中药处方配伍”监控系统,提供了临床用药指导功能,使其作为HIS的一个子系统能够实时的对医生处方进行监控,使临床医药人员记得更多、更准、更细,以降低药源性疾病,提高用药质量,加强用药管理,避免医疗纠纷。

天然产物及相关复方配伍的质谱及液相色谱研究

质谱技术以其灵敏度高、样品需求量少、快速准确的特点在生物大分子体系和天然产物的化学成分研究中起着极为重要的作用。特别是软电离质谱技术的发展，大大简化了化合物的测定过程，提高了分析研究速度，为分析植物及食物中的结构信息提供了快速便捷的方法。HPLC-ESI-MSn是90年代发展成熟的分析技术，它集液相色谱的高分离能力与质谱的高灵敏度和高专属性于一体，已成为包括药物微量杂质、药物降解产物、药代代谢动力学研究、组合化学合成产物高通量分析以及天然产物的化学筛选在内的现代药学研究领域最强有力的分析工具之一。本文首先采用电喷雾多级串联质谱技术，系统地研究了负离子条件下黄酮普元、黄酮醇普元以及二氢黄酮普元等化合物的特征质谱行为，并对中药黄芬中三种黄酮昔化合物进行了研究。利用这些特征碎片离子，可以简便快捷的区分结构类似的黄酮类化合物及其同分异构体。通过对黄酮C一昔类化合物的电喷雾串联质谱（ESI-MSn）研究，提出黄酮C-苷类化合物的特征碎裂规律，证明〔M-H-60］-，〔M-H-90］-，〔M-H-120〕-为黄酮C-苷类化合物的特征离子。为鉴定植物粗提物中黄酮类化合物奠定了基础。之后我们进一步采用高效液相色谱与电喷雾质谱联用技术，在线区分混合物中的黄酮类化合物的同分异构体。根据黄酮类化合物的电喷雾质谱规律以及化合物的色谱保留时间分析鉴定了黄答中的七种黄酮类化合物。建立了一种有效检测黄芩（Scutellariabaicalensis Georgi）中黄酮类化合物的快速灵敏的分析方法，为建立黄答药材的质量控制标准提供了借鉴。对于黄酮类化合物灵敏、快速和准确的分析方法的建立，不仅为黄酮类化合物的结构的快速鉴定提供了一定的依据，而且对生药的鉴别和制剂的质控起到重要的作用。利用电喷雾多级串联质谱技术，对化学结构相似的黄酮营、二氢黄酮营和黄酮醇昔类化合物进行了对比研究。并且首次利用高分辨质谱FTICR-MS及SORI-CID技术对naringin进行了质谱研究。利用其超高分辩率、准确质量确证了中性碎片丢失，进一步证明了我们对其碎裂机理的推断。之后，我们通过金属离子与黄酮昔溶液混合后，采用电喷雾串联质潜法进行测定。实验表明通过人为加入某些金属离子如Li+，Na+和K+，特别是Li＋可以提高黄酮昔类化合物分析灵敏度，从而提供较多结构信息。并且在串联质谱中表现不同的碎裂行为，为黄酮类化合物结构分析提供补充信息。研究表明结合〔M-H］-，〔M＋Na〕+，〔M＋Li〕+离子串联质潜提供的信息，能够有效的鉴定黄酮普的结构。本文通过电喷雾串联质谱（ESI-MSn）和液质联机技术（HPLC-ESI-MS／MS）研究了原小聚碱型生物碱。首次利用高分辨质谱FTICR-MS和SORI-CTD技术对原小桨碱型生物碱进行了高分辨质谱研究，提出了各种碎片离子的碎裂途径，并总结了原小聚碱型生物碱的质谱碎裂规律，为鉴定此类型的生物碱提供了依据。之后通过电喷雾串联质谱研究了四种生物碱化合物质谱行为。最后我们利用液质联机技术（HPLC-ESI-MSn），通过与标准品的液相保留时间对照及原小聚碱型生物碱的质谱碎裂规律，建立了分析鉴定常用中药中原小聚碱型生物碱的快捷方法。并通过选择离子监控技术（SIM）提高了对于同分异构体的分离鉴定。通过色谱UV吸收峰定量研究了这四种药用植物中小璧碱和巴马汀的含量，为临床应用提供一定的化学基础，为建立中药质量控制标准及植物分类学提供一定的依据。采用HPLC法考察了常见的黄连药对组合煎煮对黄连中小聚碱、巴马丁煎出量的影响。为制药工艺的优化奠定了基础。之后我们以中药理论为指导，按药物性味对改良半夏泻心汤中各药进行分组，利用高效液相色谱分析了不同配伍条件下小璧碱、巴马丁煎出量的变化。为组方的合理性和科学性提供了一定的化学物质基础依据。

D2-4放线菌的筛选及其抗生物质研究

利用有益微生物及其代谢产物来防治植物病害，已成为一个十分活跃并具有巨大应用前景的领域。本论文采用土壤预处理等特殊方法，从长白山不同高度的土壤中筛选出1068株放线菌。通过对峙培养法和杯碟法，筛选出D1-1等10株对蔬菜病害菌具有抑制作用的菌株。离体叶片实验中发现D2-4发酵液对黄瓜、辣椒、番茄等蔬菜真菌病害具有一定的防治效果。以水和常用化学农药作为空白和药物对照，对D2-4发酵液进行了盆栽实验，结果对番茄灰霉、辣椒根腐和黄瓜枯萎病的防治效果分别为70.65％、63.27％、65.04％，初步显示出良好的防治效果。通过单因素和均匀设计实验，优化了DZ-4菌发酵培养基的组成，考察了培养时间、接种量、菌龄等对抑菌活性的影响。确定了最佳发酵培养基成分：黄豆饼粉1.10％、葡萄糖2.71％、蔗糖1.00％、NaCl0.10％、酵母膏0.10％、发酵培养基初始pH为6.61。最佳发酵时间为96h左右，培养20～24h的种子液以7％的接种量转接有利于提高抑菌活性。经发酵培养基和发酵条件的优化，发酵液抑菌活性达到了6588 u／ml，比原始发酵培养基（3678 u／ml）活性提高了79.12％。经发酵液的预处理、离子交换层析、吸附柱层析、高效液相色谱纯化等步骤，对D2-4抗生素进行了分离纯化研究。通过纸层析、纸电泳等试验最后确定该农用抗生素为弱碱性水溶性抗生素。对D2-4抗生素纯品进行了红外吸收光谱、紫外吸收光谱等理化性质的研究。

繁茂膜海绵中放线菌的鉴定及S19抗菌素主要特性的研究

近年的研究表明，海绵微生物是某些海绵天然产物的真正产生者。因此，人们将海绵微生物作为开发海绵天然产物的重要来源之一。采用琼脂块法和液体扩散法，从分离自中国黄渤海大连海域的海绵优势种—繁茂膜海绵的28株放线菌中筛选到4株具有抗菌活性的放线菌，并对它们进行生物学鉴定。采用经典和现代分类鉴定方法，对4株具有抗菌活性的繁茂膜海绵放线菌的形态特征、培养特征、生理生化特征、细胞壁化学组分和16SrRNA序列进行了研究，得出种水平的鉴定结果：Hmp-S14为西唐氏链霉菌Streptomycessetonii；Hmp-S19为灰色链霉菌Streptomyces griseus；Hmp-S24为桔橙小单抱菌Micromonospora aurantiaca；Hmp-S26为生二素链霉菌Streptomyces ambifaciens。在四株具有抗菌活性的繁茂膜海绵放线菌中，菌株Hmp-S19的抗菌活性优于其它三株，并且与已报道的20多种灰色链霉菌菌株有不同的生理生化特性，故进一步优化其发酵条件并初步研究了S19抗菌素的理化性质。通过单因子和均匀设计实验，优化菌株Hmp-S19摇瓶发酵条件。确定最佳发酵培养基：玉米粉0.6％，葡萄糖0.1％，豆饼粉0.5％，NaCl 0.3％，KH2PO40.08％，CaCO30.08％，MgSO40.02％；最佳发酵条件：接种龄30h，接种量5％，初始pH7．0，发酵时间96h，装液量100ml／50ml，培养温度28 ℃。应用二剂量法测定519一抗菌素的相对效价，为5154μ/ml，较原始发酵培养基和发酵条件（3364μ/ml）提高了53％。通过pH纸层析和捷克八溶剂系统纸层析试验，初步判定519抗菌素为两性、非水溶性I型抗菌素。Hmp-S19发酵液经预处理、萃取、硅胶柱层析、制备薄层层析等步骤，对S19抗菌素进行分离纯化得粗制品，并进行了液 相色谱一质谱检测。