食蚜瘿蚊触角的扫描电镜观察

用扫描电子显微镜对食蚜瘿蚊角角进行了观察.结果显示,雌雄触角都为14节,其中雄性约为2000μm,雌性约为1 050μm.电镜下可观察到食蚜瘿蚊触角有6种类型的感受器,即：刺形感受器、毛形感受器、锥形感受器、腔形感受器、柱形感受器和环丝.刺形感受器较长,约67.5μm,基部有膜状的窝.毛形感受器长约61μm,末端弯曲.锥形感受器呈钉状着生在表皮上,长约4.7μm.腔形感受器呈凹陷状,腔的直径约为1.2μm.柱形感受器着生在雄虫鞭节的第二亚节,长约21μm,直径约为1.5μm.环丝,是瘿蚊类昆虫触角中特殊的结构,它通过着生在一系列腔中的的短梗,连结成环状附着在触角各亚节的表面.刺形和锥形感受器在数量上,雌雄之间差别不大;柱形感受器只在雄虫中发现;雄虫触角上的腔形感受器在数量上要比雌虫多.     

The synergistic ability of some wood-degrading fungi to transform lignins and lignosulfonates on various media

Summary In order to investigate the ligninolytic activity with mixed cultures of wood-degrading fungi, and the influence of various growth conditions on this activity, 50 wood-degrading fungi were tested for ligninolysis in pure culture and in pair-wise combinations according to a simple plate test recently developed in this laboratory. It was found that a synergistic degradation of lignin and of lignosulfonate was common among fungi inoculated pair-wise on lignin or lignosulfonate media; decomposition was enhanced in the zone where the two mycelia interacted. This synergistic effect was noted with pairs of two different white-rot fungi, with pairs of one white-rot and one brown-rot fungus, and with pairs of one white-rot and one soil Deuteromycete.Lignosulfonate was more susceptible to the synergistic action of pairs of fungi than was lignin. The synergistic attack on lignosulfonate was more pronounced on a meager medium than on a carbohydrate-rich one. On the contrary, the ligninolysis with pure cultures of the fungi was more pronounced on the carbohydrate-rich medium, and lignin was decomposed more easily than was lignosulfonate.     

Studies on cell surface fibronectin of transformed Syrian hamster lung cells induced by butyric acid

In this paper, Fn was analysed qualitatively and quantitatively in three Syrian hamster cell lines, ie, nontransformed baby hamster lung fibroblasts cell line (BHL), a transformed cell line (BHLB4) and a butyric acid-induced phenotypically reversed cell line (ButB4) respectively. Fn was visualized on cell surface by means of indirect immunofluorescence technique. Immunofluorescence of Fn on the surface of BHL was bright with a stripe-like distribution, while that on the surface of BHLB4 was very dim or dispersed. On ButB4 cell surface, the intensity and distribution of immunofluorescence was similar to that on BHLB4 cells. Fn was isolated by affinity chromatography from the cell surface of the three cell lines. Its molecular weight was 250 kDa on SDS-polyacrylamide electrophoresis. The quantity of Fn isolated from surface of ButB4 was a bit lower than that from BHL, but was much higher than that from BHLB4. The result offers us a useful criterion for transformation and reverse transformation.     

A homodimeric laccase with unique characteristics from the yellow mushroom Cantharellus cibarius

The aim of the present study was to isolate a laccase from fruiting bodies of the yellow mushroom Cantharellus cibarius. The fruiting body extract was subjected to a purification protocol that involved ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel and Con A-Sepharose, and gel filtration by fast protein liquid chromatography on Superdex 75. The laccase was unadsorbed on DEAE-cellulose and Affi-gel blue gel and adsorbed on Con A-Sepharose. The laccase was composed of two identical subunits each with a molecular mass of 46 kDa. The laccase exhibited a temperature-dependent rise in activity over the temperature range 20-50 degrees C. When the temperature was raised above 60 degrees C there was a fall in enzyme activity. The enzyme manifested maximal activity at pH 4. At and above pH 6 there was a dramatic reduction in activity. The unique features of this fruiting body laccase compared with previously reported mycelial laccases include homodimeric nature, a distinctive N-terminal sequence, a higher optimal pH, and adsorption on only ConA-Sepharose among the various chromatographic media tested.     

Micropatterned surfaces for the control of endothelial cell behaviour

Micropatterned materials were synthesised by photoimmobilising the sulphated hyaluronic acid, adequately functionalised with a photoreactive moiety, on glass substrates. Four different patterns (10, 25, 50 and 100 microns) were obtained. The spectroscopic and microscopic analysis of the microstructured surfaces revealed that the photoimmobilisation process was successful, demonstrating that the photomask was well reproduced on the sample surface. Analysis of endothelial cell behaviour on these micropatterned materials was performed in terms of adhesion, locomotion and orientation. Decreasing the stripe dimensions a more fusiform shape of the adhered endothelial cells was observed. At the same time the cell locomotion and orientation were increased. Furthermore, a photoimmobilisation of stripes of HyalS (10 and 100 microns) was performed on a continuous HyalS layer, in turn immobilised on glass substrate. Being excluded a different chemistry between the stripe and the substrate, the influence of topography on the behaviour of endothelia cells was thus envisaged.     

Study on orientation of immunoglobulin G on protein G layer

A comparative study of immunoglobulin G (IgG) immobilization was performed, both on a thiolated protein G layer, where this immobilization was due to affinity binding with an Fc fragment of IgG, and on 11-mercaptoundecanoic acid (11-MUA), where the immobilization was due to chemical bonding. The change of IgG layer formation on the two base layers as a function of the IgG concentration was investigated by surface plasmon resonance (SPR), atomic force microscopy (AFM) in a non-contact mode, and spectroscopic ellipsometry (SE). It was observed that the IgG layer was immobilized more evenly on the thiolated protein G layer than on the 11-MUA layer, based on the SPR measurements. The surface topology analysis by AFM indicated that the IgG layer was immobilized on the protein G layer according to the envelope profile of the base layer. Based on the SE analysis, it was determined that the IgG layer thickness on the thiolated protein G layer increased with increasing IgG concentration. Based on the above analyses, the scheme for orientation of IgG immobilized on the thiolated protein G layer was proposed.     

Purification and properties of sulfoacetaldehyde sulfo-lyase, a thiamine pyrophosphate-dependent enzyme forming sulfite and acetate.

Sulfoacetaldehyde sulfo-lyase, which decomposes sulfoacetaldehyde to sulfite and acetate, was extracted from a bacterium grown on taurine, and purified, and characterized. A method for assay of enzyme activity was devised on formation of a bisulfite adduct with benzaldehyde. The enzyme was purified 14-fold from an extract of cells grown on taurine and appeared homogeneous on disc-electrophoresis. The molecular weight of the enzyme was estimated to be 85,000 by gel filtration. The enzyme required thiamine pyrophosphate (TPP) and Mg2+ for activity and preincubation with TPP and Mg2+ was required for maximum activity. The optimum pH for activity was 7.5. The Km value for TPP was determined to be 2.7 muM and that for sulfoacetaldehyde to be 5.0mM. Sulfite was produced only from sulfoacetaldehyde among a variety of sulfonates tested. rho-Chloromercuribenzoate, EDTA, and sulfite, a reaction product, inhibited the enzyme reaction. The enzyme seemed to be inducible, since activity was found in extracts of cells grown on taurine but not on peptone.     

Production of extracellular enzymes by Thermomonospora curvata during growth on protein-extracted lucerne fibres

After extraction of food protein from lucerne, the residual fibre was used as a carbon and energy source by the thermophilic actinomycete, Thermomonospora curvata. Induction of catabolic exoenzymes during growth for 7 d on the fibre at 53°C in a mineral salts minimal medium was compared with that on a variety of other inductive substrates. A fibre concentration of 1.5% (w/v) was optimal for total protein secretion. The fibre was a poor substrate for amylase production due to lack of inducer rather than to catabolite repression by soluble sugars released during degradation. β-Glucosidase release during growth on the fibre was about 10 times that observed in cultures grown on cellobiose or cellulose, but production of other cellulolytic enzymes was about one-half that produced on cellulose. Pectinolytic activity (measured as polygalacturonate lyase) was equal to that produced on pectin. Cells grown on the fibre released about eight times as much proteinase as those grown on cellulose, but proteolytic activity was transient and decreased rapidly during later growth. Xylanase appeared to be co-ordinately induced with cellulolytic enzymes; comparable maximal activities, observed during growth on either the fibre or cellulose, were three times that produced on xylan or xylose.     

Female choice for male gregariousness in a Stink bug,Megacopta punctissimum (Montandon) (Heteroptera,Plataspidae)

Adults of a stink bug,Megacopta punctissimum, form mating aggregations on their host plants, based on the gregarious habit of males. A female was released on a stem on which there was an aggregation of 2 mating pairs and 1 bachelor male. Next, the bachelor male was released on a stem on which no bugs were present, and the same female was released there. Sequences of courtship behavior were compared between them. This experiement was repeated for 41 pairs of males and females, and about half (20 cases) of these experiments were made in the reverse order. Males were the active sex in courtship, whilst females either accepted the courtship, or escaped from courting males. Females accepted courtship with a higher probability when males courted in aggregations (73%) compared to solitary conditions (22%). This was because the escape behavior of females from the males was reduced if females detected the presence of other bugs near the males. It was concluded that female choice is a selective force for gregariousness in males.     

A monolithic silicon based integrated signal generation and detection system for monitoring DNA hybridisation

The aim of this work was to develop an integrated solution to DNA hybridisation monitoring for diagnostics on a monolithic silicon platform. A fabrication process was developed incorporating a gold initiation electrode patterned directly onto a PIN photodiode detector. Patterned interdigitated type electrodes exhibited the smallest reduction in photodiode sensitivity, therefore these were chosen as the ECL initiator design. A novel DNA hybridisation assay was developed based on the displacement of a partially mismatched complementary strand by a perfectly matched labelled complementary strand. Pre-hybridised thiolated oligonucleotide and unlabelled 25% mismatched oligonucleotide were assembled on the gold initiation electrode. On addition of the labelled perfectly complementary oligonucleotide, the mismatched strands were displaced and a signal was generated. The sensitivity of the photodiode to light emitted at 620 nm, the ruthenium emission wavelength, was determined and subsequently, the diode current response to light generated by flow addition of ruthenium solution was found to be measurable to a concentration of 10 fM. Pre-hybridised duplex DNA, consisting of thiolated oligonucleotide and ruthenium labelled complementary oligonucleotide, was assembled on the gold initiation electrode. The difference between the current measured during flow of buffer and the ECL co-reactant TPA was three orders of magnitude, indicating that DNA assembled on the surface comprised sufficient ruthenium to generate a measurable signal. Finally, the displacement of unlabelled partial mismatch oligonucleotide from the sensor surface was monitored on addition of the ruthenium labelled perfectly complementary oligonucleotide in TPA flow and the measured photodiode current response was up to 50 times greater.     

A Novel Tram Stent Method in the Treatment of Coronary Bifurcation Lesions – Finite Element Study

A novel stent was designed for the treatment of coronary bifurcation lesion, and it was investigated for its performance by finite element analysis. This study was performed in search of a novel method of treatment of bifurcation lesion with provisional stenting. A bifurcation model was created with the proximal vessel of 3.2 mm diameter, and the distal vessel after the side branch (2.3 mm) was 2.7 mm. A novel stent was designed with connection links that had a profile of a tram. Laser cutting and shape setting of the stent was performed, and thereafter it was crimped and deployed over a balloon. The contact pressure, stresses on the arterial wall, stresses on the stent, the maximal principal log strain of the main artery and the side-branch were studied. The study was performed in Abaqus, Simulia. The stresses on the main branch and the distal branch were minimally increased after deployment of this novel stent. The side branch was preserved, and the stresses on the side branch were lesser; and at the confluence of bifurcation on either side of the side branch origin the von-Mises stress was marginally increased. The stresses and strain at the bifurcation were significantly lesser than the stresses and strain of the currently existing techniques used in the treatment of bifurcation lesions though the study was primarily focused only on the utility of the new technology. There is a potential for a novel Tram-stent method in the treatment of coronary bifurcation lesions.     

Diauxic growth of Agrobacterium tumefaciens 15955 on succinate and mannopine.

Diauxic growth was observed upon incubation of Agrobacterium tumefaciens 15955 on a mixture of succinate and mannopine as the carbon source. Diauxic growth was also observed when either fumarate or L-malate was mixed with mannopine. No diauxie was detectable when A. tumefaciens 15955 was grown on a mixture of mannopine and glucose, fructose, sucrose, or L-arabinose. Preferential utilization of succinate was observed in the initial growth phase of diauxie, whereas the final growth phase occurred at the expense of mannopine. Cells harvested during the initial growth phase exhibited a capacity for uptake of [14C]succinate but not of [14C] mannopine. A capacity for [14C]mannopine uptake was expressed during the final growth phase. Extracts from cells grown on a mixture of succinate and mannopine exhibited a low level of mannopine cyclase activity in the initial phase of diauxie. This activity increased substantially in the final phase of growth. Added succinate had no effect on the rate of [14C]mannopine uptake or mannopine cyclase activities of cells previously grown on mannopine. Diauxie was also observed during growth of strain 15955 on a mixture of succinate and octopine.     

AN EXPERIMENT IN RABBIT CONTROL

A successful experiment in rabbit control was carried out over one year on a 300-acre farm in Pembrokeshire. The control measures adopted were trapping, gassing and ferreting, in that order. Information on rabbit density was based primarily on counts of rabbit holes and on the number of animals caught. Observations were made on the breeding state and sex ratio of the population. Successful control was attributed to the persistent application of a variety of methods, and not to any one method in particular. Gassing was equally efficient on high and low rabbit populations; the three methods of application, namely pumping, spooning and a combination of both, were found to be equally effective. Re-infestation occurred, but was checked to some extent by trapping around the boundary.
The breeding season appeared to extend from January to June, inclusive. The sex ratio was biased in favour of females throughout the experiment. An almost even sex ratio was observed in embryos.     

河流两侧坡面非对称采伐森林对流域暴雨-径流过程的影响

通过模拟实验比较了河流两侧坡面采伐与非采伐森林对流域暴雨径流的影响 ,并建立了模型 .结果表明 ,森林坡面地表径流的出流时间和峰现时间均比采伐坡面迟缓 ,径流历时延长 ,峰值流量和地表径流总量较低 .坡度越大 ,影响越显著 .当雨强 1.98mm·min-1,降雨量 10 8.8mm时 ,15°两侧森林坡面比其采伐坡面峰值流量削减 5 % ,径流总量降低 4% .     

Polar distribution dynamics of Con A binding sites in embryo sacs is temporally coupled by the fertilization process

The binding site distribution of concanavalin agglutinin (Con A) and wheat germ agglutinin (WGA) on embryo sacs at various developmental stages of Torenia fournieri L was studied by using a cooled Charge Coupled Device (CCD) and fluorescent Con A and WGA probes. The distribution patterns of Con A and WGA binding sites on embryo sacs changed during the fertilization process. The fluorescent signal indicating Con A binding sites was distributed evenly on the surface of the embryo sac wall before anthesis, was much denser on the micropylar end of the embryo sac wall and looked like a corona on the day of anthesis. After pollination, stronger fluorescence was present on the micropylar end of the embryo sac wall and the filiform apparatus (FA), showing an obvious polar distribution. When the pollen tube entered the embryo sac and reached a synergid, the fluorescence was still concentrated on the micropylar end and FA, and started to appear on the synergid. After fertilization, the polar distribution of the fluorescence gradually disappeared and an even distribution pattern was observed again on the embryo sac wall. These results revealed that the dynamic distribution of Con A binding sites was temporally coupled with the process of fertilization. WGA binding site distribution on the embryo sac was also investigated and showed a simple pattern but also regularly changed during the process of fertilization. The variation of these lectin binding sites during the fertilization process suggests that lectin binding site interactions may play a role in the process.     

Development of fluorescence change-based, reagent-less optic immunosensor

A reagent-less, regenerable and portable optic immunosensor was developed. A model sample, immunoglobulin G (IgG), was detected with this system based on changes in fluorescent intensity of fluorescent labeled protein A with specific reactivity to IgG depending on a reaction between the proteins. A glass plate immobilized with Qdot-labeled protein A was placed on the top of optic fibers designed for both excitation and fluorescence emission. The optic fibers with the Qdot-labeled protein A-immobilized glass plate were inserted into a solution of pH 7.4 phosphate buffered saline. After stabilization of the fluorescence intensity, IgG was added and the time-course of the fluorescence intensity was measured on a fluorometer connected with the optic fibers. Furthermore, the fluorescence response of a transient state was evaluated with the same system. When the Qdot-labeled protein A bound to IgG, fluorescence intensity decreased because of the inhibition by IgG. The degree of fluorescence decrease depends on the IgG concentration at a steady state and also in a transient state.     

Immunolocalization of angiotensin 1 converting enzyme in the human male genital tract by the avidin-biotin-complex method

Summary Immunoreactivity for Angiotensin 1 Converting Enzyme was investigated in a series of 12 fixed and paraffinembedded normal human genital tract specimens. The Avidin-Biotin-Complex immunoperoxidase method was used with overnight (12 h) incubation with a polyclonal antihuman kidney Angiotensin 1 Converting Enzyme antiserum. All tissues, including testis, different parts of epididymis, ductus deferens, prostate and seminal vesicles, demonstrated a staining pattern. Immunoreactivity was observed on the luminal surface of these epithelia especially on nonmotile stereocilia. An intracellular positivity was only observed in spermatids on the acrosomal cap. Besides, an immunologic identity of Angiotensin 1 Converting Enzyme located on the different epithelia of the human male genital tract, on the endothelial cells of vessels and on the proximal tubule brush border of the kidney was observed.     

Immunolocalization of angiotensin 1 converting enzyme in the human male genital tract by the avidin-biotin-complex method

Immunoreactivity for Angiotensin 1 Converting Enzyme was investigated in a series of 12 fixed and paraffin-embedded normal human genital tract specimens. The Avidin-Biotin-Complex immunoperoxidase method was used with overnight (12 h) incubation with a polyclonal antihuman kidney Angiotensin 1 Converting Enzyme antiserum. All tissues, including testis, different parts of epididymis, ductus deferens, prostate and seminal vesicles, demonstrated a staining pattern. Immunoreactivity was observed on the luminal surface of these epithelia especially on non-motile stereocilia. An intracellular positivity was only observed in spermatids on the acrosomal cap. Besides, an immunologic identity of Angiotensin 1 Converting Enzyme located on the different epithelia of the human male genital tract, on the endothelial cells of vessels and on the proximal tubule brush border of the kidney was observed.     

Characterization of an antiserum to guinea pig antithrombin III (AT III). I. Reactivity with guinea pig T lymphocytes

In the course of studies investigating the effects of antisera prepared against a variety of guinea pig proteins on lymphocyte function, a goat antiserum prepared against a guinea pig gamma-globulin preparation was found to react with guinea pig T lymphocytes. This antiserum, serum 592, contained a significant titer of antibodies that were cytotoxic for a subpopulation of lymph node cells and thymocytes, and mitogenic for lymph node T cells. Immunoelectrophoretic analysis and selective absorptions of the antiserum demonstrated that the antigen recognized on thymocytes was also present on an alpha 2 globulin in guinea pig plasma, which, on the basis of physiochemical characteristics and heparin-binding affinity, appeared to be guinea pig antithrombin III (AT III). Although the antiserum was shown to contain antibodies to both protein and carbohydrate determinants on the AT III molecule, studies comparing the effects of 7 M guanidine and periodate oxidation on the antigenicity of the AT III determinant also recognized on the thymocytes indicated that this shared antigenic determinant was carbohydrate in nature. The thymocyte membrane molecule bearing this determinant was also isolated and was found to be a 210,000-dalton macromolecule that was very sensitive to proteolytic and/or autolytic degradation. These data raise the interesting possibility that guinea pig lymphoid cells may have a membrane-associated protease inhibitor related to plasma AT III.     

Characterization of the naphthalene-degrading bacterium, Rhodococcus opacus M213

Bacterial strain M213 was isolated from a fuel oil-contaminated soil in Idaho, USA, by growth on naphthalene as a sole source of carbon, and was identified as Rhodococcus opacus M213 by 16S rDNA sequence analysis and growth on substrates characteristic of this species. M213 was screened for growth on a variety of aromatic hydrocarbons, and growth was observed only on simple 1 and 2 ring compounds. No growth or poor growth was observed with chlorinated aromatic compounds such as 2,4-dichlorophenol and chlorobenzoates. No growth was observed by M213 on salicylate, and M213 resting cells grown on naphthalene did not attack salicylate. In addition, no salicylate hydroxylase activity was detected in cell free lysates, suggesting a pathway for naphthalene catabolism that does not pass through salicylate. Enzyme assays indicated induction of catechol 1,2-dioxygenase and catechol 2,3-dioxygenase on different substrates. Total DNA from M213 was screened for hybridization with a variety of genes encoding catechol dioxygenases, but hybridization was observed only with catA (encoding catechol 1,2-dioxygenase) from R. opacus 1CP and edoD (encoding catechol 2,3-dioxygenase) from Rhodococcus sp. I1. Plasmid analysis indicated the presence of two plasmids (pNUO1 and pNUO2). edoD hybridized to pNUO1, a very large (approximately 750 kb) linear plasmid.