WATER-SOLUBLE AND AMPHIPHILIC POLYMERS .6. A STUDY ON THE SURFACE-COMPOSITION OF CAST FILMS OF PST/PMAA AND PEO-PST-PEO BLOCK POLYMERS BY XPS

Thin films of PSt/PMAA and PEO-PSt-PEO block polymers were deposited on a polystyrene substrate by solution adsorption (with or without solvent treatment), and the film surfaces were characterized by means of XPS. Direct solvent - casting of PEO-PSt-PEO from benzene solutions resulted in PSt-rich surfaces, whereas PMAA richer surfaces were obtained for PSt/PMAA films cast from DMF solutions. Moreover, solvent treatment after casting had profound effect on the film surface composition. Treatment with water markedly increased the surface concentration of polar PEO segments. In the case of PSt-PMAA block polymers, the PSt content on the surface increased in the order of water < ethanol < cyclohexane < petroleum ether, the last-named giving films with almost pure PSt surface. It is well worth noticing that the bulk composition had little to do with the surface composition for both PSt/PMAA and PEO-PSt-PEO block polymers within the composition range investigated when subsequent solvent treatment was applied.

Screening of salt tolerant watercress variants on natural seawater contained medium

The responses of stem segments of watercress (Nasturtium officinale R. Br.) to 6-BA,NAA and 2,4-D were studied. MS medium supplemented with 2.0 mg/L 6-BA, 0.2 mg/L 2,4-D was used for callus initiation and maintenance. MS medium supplemented with 4.0 mg/L 6-BA was suitable for plant regeneration and MS medium without plant hormone supplement was used for rooting and plant propagation. For screening of salt tolerant calli, stem segments of watercress were plated onto callus initiation medium containing 1/3 natural seawater. Seventeen out of the 325 plated explants produced calli. The growth curves demonstrated that the growth rate of salt-tolerant calli on saline medium almost matched that of the control calli on normal medium. Some of the salt-tolerant calli were transferred to the normal regeneration medium or saline regeneration medium to induce plant regeneration. In the first case, buds and shoots were regenerated in the same way as those of control calli on normal regeneration medium. More than 1 000 regenerated shoots were obtained of which 83 regenerated shoots were cut and transferred to saline MS base medium. At first, all shoot growth was inhibited, but 40 days after the transfer, rapid-growing axillary shoots were observed on 16 of the original shoots but none on the control shoots on saline MS base medium. Moreover, green spots appeared on most calli 10 days after they were transferred to saline medium, however buds appeared only on 5 calli from the 30 transferred calli and at the end only 2 rapid-growing shoots were obtained from two calli. In total, 18 variant lines were obtained through. propagation of the salt-tolerant shoots on saline MS base medium. RAPD analysis was performed in 10 of the 18 salt-tolerant variant lines and DNA variation was detected in all the tested variant lines.

Topographic changes in nascent and early mesoderm in amphioxus embryos studied by Dil labeling and by in situ hybridization for a Brachyury gene

In amphioxus embryos, the nascent and early mesoderm (including chorda-mesoderm) was visualized by expression of a Brachyury gene (AmBra-2). A band of mesoderm is first detected encircling the earliest (vegetal plate stage) gastrula sub-equatorially. Soon thereafter, the vegetal plate invaginates. resulting in a cap-shaped gastrula with the mesoderm localized at the blastoporal lip and completely encircling the blastopore. As the gastrula stage progresses, DiI (a vital dye) labeling demonstrates that the entire mesoderm is internalized by a slight involution of the epiblast into the hypoblast all around the perimeter of the blastopore. Subsequently. during the early neurula stage, the internalized mesoderm undergoes anterior extension mid-dorsally (as notochord) and dorsolaterally (in paraxial regions when segments will later form). By the late neurula stage, AmBra-2 is no longer transcribed throughout the mesoderm as a whole; instead. expression is detectable only in the posterior mesoderm and in the notochord, but not in par axial mesoderm where definitive somites have formed.

Characterizing a monotopic membrane enzyme. Biochemical, enzymatic and crystallization studies on Aquifex aeolicus sulfide:quinone oxidoreductase

Monotopic membrane proteins are membrane proteins that interact with only one leaflet of the lipid bilayer and do not possess transmembrane spanning segments. They are endowed with important physiological functions but until now only few of them have been studied. Here we present a detailed biochemical, enzymatic and crystallographic characterization of the monotopic membrane protein sulfide:quinone oxidoreductase. Sulfide:quinone oxidoreductase is a ubiquitous enzyme involved in sulfide detoxification, in sulfide-dependent respiration and photosynthesis, and in heavy metal tolerance. It may also play a crucial role in mammals, including humans, because sulfide acts as a neurotransmitter in these organisms. We isolated and purified sulfide:quinone oxidoreductase from the native membranes of the hyperthermophilic bacterium Aquifex aeolicus. We studied the pure and solubilized enzyme by denaturing and non-denaturing polyacrylamide electrophoresis, size-exclusion chromatography, cross-linking, analytical ultracentrifugation, visible and ultraviolet spectroscopy, mass spectrometry and electron microscopy. Additionally, we report the characterization of its enzymatic activity before and after crystallization. Finally, we discuss the crystallization of sulfide:quinone oxidoreductase in respect to its membrane topology and we propose a classification of monotopic membrane protein crystal lattices. Our data support and complement an earlier description of the three-dimensional structure of A. aeolicus sulfide:quinone oxidoreductase (M. Marcia, U. Ermler, G. Peng, H. Michel, Proc Natl Acad Sci USA, 106 (2009) 9625-9630) and may serve as a reference for further studies on monotopic membrane proteins. (C) 2010 Elsevier B.V. All rights reserved.

Dissection and localization of the immunostimulating domain of Edwardsiella tarda FliC

Bacterial flagellin is known to induce potent immune response in vertebrate systems via the toll-like receptor (TLR) 5. As a result, flagellin has been studied extensively as a vaccine adjuvant. In a previous study, we examined the vaccine and adjuvant potentials of the flagellin (FliC) of the fish pathogen Edwardsiella tarda. We found that E. tarda FliC induced low protective immunity by itself but could function as a molecular adjuvant and potentiate the specific immune response induced by the E. tarda antigen Eta6. Since FliC is a large protein and organized into distinct structural domains, we wondered whether the immunostimulating effect observed with the full-length protein could be localized to a certain region. To investigate this question, we in the present study dissected the FliC protein into several segments according to its structural features: (i) N163, which consists of the conserved N-terminal 163 residues of FliC; (ii) M160, which consists of the variable middle 160 residues; (iii) C94, which consists of the conserved C-terminal 94 residues; (iv) NC257, which is an artificial fusion of N163 and C94. To examine the adjuvanticity of the FliC fragments, DNA vaccine plasmids expressing FliC fragments in fusion with Eta6 were constructed and used to immunize Japanese flounder. The results showed that N163 produced the best adjuvant effect, which, in respect to improvement in the relative percent survival of the vaccinated fish, was comparable to that of the full-length FliC. None of the other FliC fragments exhibited apparent immunopotentiating effect. Further analysis showed that N163 enhanced the production of serum specific antibodies and, like full-length FliC, significantly upregulated the expression of the genes that are possibly involved in innate and adaptive immunity. These results indicate that N163 is the immunodominant region of FliC and suggest that E. tarda FliC may induce immune responses in Japanese flounder via mechanisms alternative to that involving TLR5. (C) 2010 Elsevier Ltd. All rights reserved.

Predicting protein interaction interfaces from protein sequences: Case studies of subtilisin and phycocyanin

Identification of protein interaction interfaces is very important for understanding the molecular mechanisms underlying biological phenomena. Here, we present a novel method for predicting protein interaction interfaces from sequences by using PAM matrix (PIFPAM). Sequence alignments for interacting proteins were constructed and parsed into segments using sliding windows. By calculating distance matrix for each segment, the correlation coefficients between segments were estimated. The interaction interfaces were predicted by extracting highly correlated segment pairs from the correlation map. The predictions achieved an accuracy 0.41-0.71 for eight intraprotein interaction examples, and 0.07-0.60 for four interprotein interaction examples. Compared with three previously published methods, PIFPAM predicted more contacting site pairs for 11 out of the 12 example proteins, and predicted at least 34% more contacting site pairs for eight proteins of them. The factors affecting the predictions were also analyzed. Since PIFPAM uses only the alignments of the two interacting proteins as input, it is especially useful when no three-dimensional protein structure data are available.

Tectonics of the southern tip of the Parece Vela Basin, Philippine Sea Plate

We report new geophysical and petrological data collected at the southern tip of the Parece Vela Basin in the Philippine Sea. The Parece Vela Basin, which was formed as a backarc basin behind proto Mariana arc-trench system from late Oligocene to middle Miocene, provides us a good opportunity to study the nature of successive backarc basin formations in the Philippine Sea and the relationship between are and backarc magmatisms. Regional bathymetric map derived from satellite altimetry shows that the southern tip of the basin, now located just west of the Yap arc-trench system, has unique morphological and tectonic features which include: 1) the absence of spreading center or its trace, 2) shallow average depth, and 3) enigmatic curved structures. Our newly collected high-resolution bathymetric data reveal that the spreading fabric similar to the central Parece Vela Basin exists to the north of 9 degrees 20'N. Thus it appears that the present-day Yap arc and backarc region represent the western half of the seafloor that was produced by the early E-W and the following NE-SW spreading in the northern and central Parece Vela Basin, and that the eastern counterpart now lies west of the West Mariana Ridge. Unlike the northern Parece Vela Basin, there appears to be no evidence for a systematic propagation of spreading center in the southern part. Instead two rift segments, one which extends from the central Parece Vela Basin and the other which lies within the western remnant arc (Kyushu-Palau Ridge), overlap at the southern tip of the basin, producing a complex seafloor that includes curvilinear deeps and deformed topographic highs. (c) 2007 Elsevier B.V. All rights reserved.

Geomorphology, sedimentary processes and development of the Zenisu deep-sea channel, northern Philippine Sea

The Zenisu deep-sea channel originates on the Izu-Ogasawara island arc, and disappears in the Shikoku Basin of the Philippine Sea. The geomorphology, sedimentary processes, and the development of the Zenisu deep-sea channel were investigated on the basis of swath bathymetry, side-scan sonar imagery, submersible observations, and seismic data. The deep-sea channel can be divided into three segments according to the downslope gradient and channel orientation. They are the Zenisu Canyon, the E-W fan channel, and the trough-axis channel. The sediment fill is characterized by turbidite and debrite deposition and blocky-hummocky avalanche deposits on the flanks of the Zenisu Ridge. In the Zenisu Canyon and the Zenisu deep-sea channel, sediment transport by turbidity currents generates sediment waves (dunes) observed during the Shinkai 6500 dive 371. The development of the Zenisu Canyon is controlled by a N-S shear fault, whereas the trough-axis channel is controlled by basin subsidence associated with the Zenisu Ridge. The E-W fan channel was probably affected by the E-W fault and the basement morphology.

Sedimentary processes and development of the Zenisu deep-sea channel, Philippine Sea

Zenisu deep-sea channel originated from a volcanic arc region, Izu-Ogasawara Island Arc, and vanished in the Shikoku Basin of the Philippine Sea. According to the swath bathymetry, the deep-sea channel can be divided into three,segments. They are Zenisu canyon, E-W fan channel and trough-axis channel. A lot of volcanic detritus were deposited in the Zenisu Trough via the deep-sea channel because it originated from volcanic arc settings. On the basis of the swath bathymetry, submersible and seismic reflection data, the deposits are characterized by turbidite and debrite deposits as those in the other major deep-sea channels. Erosion or few sediments were observed in the Zenisu canyon, whereas a lot of turbidites and debrites occurred in the E-W channel and trough axis channel. Cold seep communities, active fault and fluid flow were discovered along the lower slope of the Zenisu Ridge. Vertical sedimentary sequences in the Zenisu Trough consist of the four post-rift sequence units of the Shikoku Basin, among which Units A and B are two turbidite units. The development of Zenisu canyon is controlled by the N-S shear fault, the E-W fan channel is related to the E-W shear fault, and the trough-axis channel is related to the subsidence of central basin.

Detection of transgenic DNA in tilapias (Oreochromis niloticus, GIFT strain) fed genetically modified soybeans (Roundup Ready)

We used nested-polymerase chain reaction (PCR) to detect Roundup Ready soybean in aquatic feeds and feeding tilapias. A template concentration of 10(-10) g mu L-1 DNA solution could be detected with a dilute degree of 0.01%. Most (90.6%) of the aquatic feeds containing soybean byproduct included exogenous DNA segments. We also compared genetically modified (GM) soybean with non-GM soybean diets in feeding tilapias (Oreochromis niloticus, GIFT strain) and examined the residual fragments (254 bp) of GM soybeans. Tilapias receiving GM soybean diets had DNA fragments in different tissues and organs, indicating that exogenous GM genes were absorbed systemically and not completely degraded by the tilapia's alimentary canal.

冗余度机器人作业区域轨迹的自动规划

机器人化是提高工程机械施工控制自动化的关键问题。对于工程机械机器人 ,特别是具有空间冗余度的工程机械机器人 ,其执行机构末端的轨迹规划的自动实现研究对提高其自动化程度有着重要意义。本文以泵车为例 ,提出了一种泵车布料机构的浇筑过程的自动轨迹规划算法 ,该算法通过将其所浇筑区域离散成浇筑点集 ,对两浇筑点的轨迹利用冗余度机器人学的最小关节范数法 ,并通过在关节速度和加速度非连续之处采用平滑或连续处理 ,从而实现了泵车布料机构浇筑过程的自动轨迹规划。

混凝土泵车布料机构自动浇筑及过程仿真

机器人化是提高工程机械施工控制自动化的关键问题·通过将泵车布料机构的浇筑区域离散为浇筑点集 ,对两浇筑点内轨迹利用冗余度机器人学的最小关节范数法的轨迹规划 ,并将两相临浇筑段自动连接和自动协调 ,从而实现了混凝土泵车布料机构浇筑过程自动轨迹规划·

关于参数规划在自治智能移动式机器人中实际应用的探讨

机器人行走空间的复杂性决定了导航监控系统不仅为机器人提供行走路线,还要依据预先得到的先验数据与知识告诉机器人不同行走段的障碍分布、环境边界走向及约束程度,按照载体的几何形状,运动特性选择合适的速度、加速度,保证在安全的前提下最快完成行走.本文讨论了提取影响机器人当前行走的障碍、环境边界算法和不同行走速度段的划分与关键点抽取方法,讨论了各种速度段的分离、合并、高速行走段的插补和过短行走段的平滑滤除等等.

鄂尔多斯盆地环县地区长6-长8沉积相及储层研究

The exploration in recent years shows that the Yanchang Formation in the southwest of Ordos Basin is of great resource potential and good exploration and exploitation prospect. In the thesis ，sedimentary source analysis，sedimentary system，sedimentary microfacies，sandstones distribution and reservoir characteristic are studied and favorable oil area are forecasted in Chang6-Chang8 of Yanchang formation in HuanXian region， by mainly study on the data of field section observation ，core observation, well logging explaination and routine microscope slice identification，scanning Electron Microscope and reservoir analysis of lithology and physical property , Under the guidance of such advanced theories and methods as sedimentology，reservoir sedimentology，lithological oil pool and so on. The stratum of Chang6-Chang8 of Yanchang formation could be divided into pieces of member following the principles that firstly contrasting the big segments, then contrasting the small segments, being controlled by cycle and consulting the thickness etc.And the characteristic of stratum are detailed discussed , respectively. Based on the source direction of the central basin, heavy and light minerals are used to analyse source direction of Chang6 and Chang8 member, in HuanXian area. Research result shows that the source of Chang6 and Chang8 member is mixed provenance,including west-south,west and east-north. By the study of rock types、 sedimentary conformation、lithology and electromotive curve combination and palaeo-biology,lake、delta and braided delta mianly developed in study area are recognized, Subaqueous distributary channels in delta front and in braided delta front, and sand body in deep-lake turbidite, are the main reservoir.forthermore,the characteristic of depositional system and sandy body in space are discussed. Applied with routine microscope slice identification, Scanning Electron Microscope, reservoir lithology and physical property analysis and other analytic machinery, Feldspar-lithic fine-sandstone and feldspar fine-sandstone are mainly sandstone of Y Chang6-Chang8 in Huanxian area, small pore and tiny pore are the main pore types, tiny throat type and micro-fine throat type are widely developed , secondary dissolution porosity, intercrystal porosity, tiny pore and micro-crack are main pore types.Intergranular porosity and dissolution porosity secondary is the main pore secondary. The dominant diagenesis types in the area are compaction, cementation, replacement and dissolution. Chlorite films cementation facies, carbonate cementation facies ,mud cementation compaction facie, compaction 、pressure solution facies are the main diagenetic facies,in which Chlorite films cementation facies is the best diagenetic facies in study area. Reservoir influence factor analysis ,rock types are the main factor forming this low-pore and low-permeability of Chang6-Chang8 member in study area,and relatively higher permeability area are cortrolled by sedimentary facies distribution, diagenesis improved reservoir physical property. According to the distributing of sedimentary micro-facies and sandy body , and the test oil, favorable region in Chang6-Chang8 are forecasted.

陕北地区石家湾-李家岔探区三叠系延长组石油成藏条件分析

Shijiawan –Lijiacha area, lying on the northeastern part of the Shanbei Slope of Ordos Basin, was selected as studying area. The previous explorations proved that the 2nd segment and 6th segment of the Yanchang Formation are the most important oil-bearing formations. It is indicated that the sedimentary facies and reservoir characteristics restricted the hydrocarbon accumulation regularity. Therefore, with petrology methodologies, such as outcrop observation, core description, geophysical logging interpretation, thin section determination, scanning electron microscope, as well as rock property analysis, the reservoirs was were systematically studied and characterized. The sedimentary micro-facies, seals, reservoir-seal combines, migration pathways and entrapping modes were taken into account. The author tempted to establish a base for further studies on reservoirs and on petroleum geology, and to provide some reliably geological evidences for later prospect activities. It was found that the sediments in the 2nd and 3rd segments of the Yanchang Formation in Shijiawan –Lijiacha area were deposited in braided rivers, and most sandy-bodies were identified as channel sandbars. The 4+5th and 6th segments were principally deposited in deltaic-plain environment, consisting of corresponding sub-facies such as distributary channels, natural levee, crevasse-splay and marsh. The skeleton sandy-bodies were identified as sandy sediments of distributary channels. The sand grains in reservoir in studied area possess generally low mineralogical maturity and moderate structural maturity, and the form of pores may be classified into intergranular types and dissolved types. Most reservoirs of Yanchang Formation in Shijiawan –Lijiacha area belong to extreme low-porosity low-permeability ones (type III), and the 2nd sediments belongs to low permeability one (type II) and the 6th segment belong to super low-permeability one(type Ⅳ). The reservoirs in the 2nd segment behave more heterogeneous than those in the 6th segment. The statistic analysis results show that, for 6th and 4+5th segments, the high quality reservoir-seal combines may be found everywhere in the studied area except in the northwest and the southwest parts; and for 1st and 2nd segments, in the northeast, central and southwest parts Petroleum migration happened in the duration of the Early Cretaceous period in both lateral and vertical directions. The migration paths were mainly constructed by permeable sandy-bodies. The superimposed channel sandy-bodies consist of the principal part of the system of carriers. the vertical fractures, that may travel through the seals between reservoirs, offered the vertical paths for migrating oil. It may be synthesized that oil coming from south kitchens migrated first laterally in carriers in the 6th segment. When arrived at the studied area, oil will migration laterally or/and vertical within both the sandy-bodies and fractures, in a climbing-stair way. The results demonstrate that the oil was entrapped in traps structure-lithology and/or lithology traps. In some cases, the hydrodynamic force may help to trap oil. Accumulation of oil in the area was mainly controlled by sedimentary facies, seals, structure, and heterogeneity of reservoir in the 2nd, 4+5th and 6th segments. Especially, the oil distributions in both the 2nd and 6th segments were obviously influenced by seals in the 4+5th segment. The existence of seals in 1st segment seems important for accumulation in the 2nd segment.