113 resultados para AK37-3821


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抗生素产生菌的自身防卫机制研究李明祺,吴文芳,张成刚(中国科学院沈阳应用生态研究所,110015)抗生素是在微生物初级代谢过程中,由于特定的分支点受到阻碍而产生的物质,即所谓次级代谢物质。自然界中这种次级代谢物在微生物体内含量少,尚不至于对产生菌构成...

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Bagnold-type bed-load equations are widely used for the determination of sediment transport rate in marine environments. The accuracy of these equations depends upon the definition of the coefficient k(1) in the equations, which is a function of particle size. Hardisty (1983) has attempted to establish the relationship between k(1) and particle size, but there is an error in his analytical result. Our reanalysis of the original flume data results in new formulae for the coefficient. Furthermore, we found that the k(1) values should be derived using u(1) and u(1cr) data; the use of the vertical mean velocity in flumes to replace u(1) will lead to considerably higher k(1) values and overestimation of sediment transport rates.

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Timmis J Neal M J and Hunt J. Augmenting an artificial immune network using ordering, self-recognition and histo-compatibility operators. In Proceedings of IEEE international conference of systems, man and cybernetics, pages 3821-3826, San Diego, 1998. IEEE.

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There has been a long history of defining T cell epitopes to track viral immunity and to design rational vaccines, yet few data of this type exist for bacterial infections. Bacillus anthracis, the causative agent of anthrax, is both an endemic pathogen in many regions and a potential biological warfare threat. T cell immunity in naturally infected anthrax patients has not previously been characterized, which is surprising given concern about the ability of anthrax toxins to subvert or ablate adaptive immunity. We investigated CD4 T cell responses in patients from the Kayseri region of Turkey who were previously infected with cutaneous anthrax. Responses to B. anthracis protective Ag and lethal factor (LF) were investigated at the protein, domain, and epitope level. Several years after antibiotic-treated anthrax infection, strong T cell memory was detectable, with no evidence of the expected impairment in specific immunity. Although serological responses to existing anthrax vaccines focus primarily on protective Ag, the major target of T cell immunity in infected individuals and anthrax-vaccinated donors was LF, notably domain IV. Some of these anthrax epitopes showed broad binding to several HLA class alleles, but others were more constrained in their HLA binding patterns. Of specific CD4 T cell epitopes targeted within LF domain IV, one is preferentially seen in the context of bacterial infection, as opposed to vaccination, suggesting that studies of this type will be important in understanding how the human immune system confronts serious bacterial infection.

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An architecture to simultaneously affect both amplitude and phase control from a reflectarray element using an impedance transformation unit is demonstrated. It is shown that a wide range of control is possible from a single element, removing the conventional necessity for variable sized elements across an array in order to form a desired reflectarray far-field pattern. Parallel plate waveguide measurements for a 2.2 GHz prototype element validate the phase and amplitude variation available from the element. It is demonstrated that there is sufficient control of the element's reflection response to allow Dolph-Tschebyscheff weighting coefficients for major-lobe to side-lobe ratios of up to 36 dB to be implemented.

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A set of 57 synthetic peptides encompassing the entire triple-helical domain of human collagen III was used to locate binding sites for the collagen-binding integrin alpha(2)beta(1). The capacity of the peptides to support Mg2+-dependent binding of several integrin preparations was examined. Wild-type integrins (recombinant alpha(2) I-domain, alpha(2)beta(1) purified from platelet membranes, and recombinant soluble alpha(2)beta(1) expressed as an alpha(2)-Fos/beta(1)-Jun heterodimer) bound well to only three peptides, two containing GXX'GER motifs (GROGER and GMOGER, where O is hydroxyproline) and one containing two adjacent GXX'GEN motifs (GLKGEN and GLOGEN). Two mutant alpha(2) I-domains were tested: the inactive T221A mutant, which recognized no peptides, and the constitutively active E318W mutant, which bound a larger subset of peptides. Adhesion of activated human platelets to GER-containing peptides was greater than that of resting platelets, and HT1080 cells bound well to more of the peptides compared with platelets. Binding of cells and recombinant proteins was abolished by anti-alpha(2) monoclonal antibody 6F1 and by chelation of Mg2+. We describe two novel high affinity integrin-binding motifs in human collagen III (GROGER and GLOGEN) and a third motif (GLKGEN) that displays intermediate activity. Each motif was verified using shorter synthetic peptides.

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The oxidation of trimethoxymethane (TMM) (trimethyl orthoformate) in a direct oxidation PBI fuel cell was examined by on-line mass spectroscopy and on-line FTIR spectroscopy. The results show that TMM was almost completely hydrolyzed in a direct oxidation fuel cell which employs an acid doped polymer electrolyte to form a mixture of methylformate, methanol and formic acid. It also found that TMM was hydrolyzed in the presence of water at 120°C even without acidic catalyst. The anode performance improves in the sequence of methanol, TMM, formic acid/methanol, and methylformate solutions. Since formic acid is electrochemically more active than methanol, these results suggest that formic acid is probably a key factor for the improvement of the anode performance by using TMM instead of methanol under these conditions. © 1998 Elsevier Science Ltd. All rights reserved.

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Valtatien 13 osuus Lappeenrannasta Nuijamaalle kuuluu Euroopan komission päättämään Suomen kattavaan liikenneverkkoon TEN-T. Tieosuus on maan toiseksi tärkein kansainvälisen liikenteen yhteys kuljetuksille ja henkilöliikenteelle. Valtatie 13 kulkee maan poikki länsirannikolta Kokkolasta Lappeenrantaan ja siitä edelleen Nuijamaan rajanylityspaikan kautta Venäjän puolelle Viipuriin. Valtatie 13 palvelee osaltaan myös paikallista liikkumista Nuijamaan kylätaajaman ja Lappeenrannan välillä. Erityisesti Mustolan alueelle ja myös osittain Nuijamaan raja-aseman läheisyyteen suunnitellut ja jo osittain toteutuneet maankäytön kaupalliset palvelut lisäävät voimakkaasti kasvaessaan myös seudullista liikennettä suunnitteluosuudella. Nuijamaan raja-asema on ollut Suomen itärajan toiseksi vilkkain tieliikenteen rajanylityspaikka. Rajanylityspaikan kautta kulki vuonna 2015 noin miljoona ajoneuvoa ja 2,4 miljoonaa matkustajaa. Venäjän ja Suomen valtioiden välisen liikenteen kasvu on ollut voimakkainta Kaakkois-Suomessa ja sille on edelleen perusteltuja kasvuodotuksia, vaikka viime aikoina liikenne on merkittävästi vähentynyt. Myös tavaraliikenteellä on potentiaalia lisääntyä viimeaikaisesta. Suunnittelualueeseen kuuluu valtatien 13 (16,6 km) lisäksi valtatien 6 länsipuolinen valtatien 13 jatke Karjalantie (mt 3821) (1,2 km). Yleissuunnitelmassa on selvitetty valtatien 13 puutteet ja ongelmat, palvelutasotavoitteet, valtatien 13 ja muiden väylien periaateratkaisut tilantarpeineen, suhde ympäröivään maankäyttöön, vaikutukset sekä mahdollisuudet vaiheittain toteuttamiseksi. Päätavoitteena on ollut selvittää valtatien 13 ja muiden väylien kehittämisen periaatteet niin, että palvelutasopuutteet saadaan poistettua ja valtatie 13 vastaa sille asetettuja vaatimuksia liikenteen sujuvuuden ja turvallisuuden kannalta. Osana suunnitelmaa on esitetty toimenpiteet meluhaittojen torjumiseksi ja ympäristövaikutusten lieventämiseksi. Valtatie 13 parannetaan nykyisellä paikallaan korkealuokkaiseksi nelikaistaiseksi valtatieksi tarvittavine tie-, katu- ja liittymäjärjestelyineen. Vastakkaiset ajosuunnat on erotettu toisistaan rakenteellisesti ja kaikki valtatien liittymät ovat eritasoliittymiä.

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1894/11/12 (Numéro 3821).

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[Mazarinade. 1650]

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Doctrina