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1.
A new algorithm is proposed to determine the type-II restrictionendonucleases' recognition site knowing the digested DNA sequenceand fragment lengths in an actual case. The algorithm is implementedfor the Commodore 64 microcomputer.
Received on January 6, 1987; accepted on June 19, 1987 相似文献
2.
Adding noise to a visual image makes object recognition more effortful and has a widespread effect on human electrophysiological responses. However, visual cortical processes directly involved in handling the stimulus noise have yet to be identified and dissociated from the modulation of the neural responses due to the deteriorated structural information and increased stimulus uncertainty in the case of noisy images. Here we show that the impairment of face gender categorization performance in the case of noisy images in amblyopic patients correlates with amblyopic deficits measured in the noise-induced modulation of the P1/P2 components of single-trial event-related potentials (ERP). On the other hand, the N170 ERP component is similarly affected by the presence of noise in the two eyes and its modulation does not predict the behavioral deficit. These results have revealed that the efficient processing of noisy images depends on the engagement of additional processing resources both at the early, feature-specific as well as later, object-level stages of visual cortical processing reflected in the P1 and P2 ERP components, respectively. Our findings also suggest that noise-induced modulation of the N170 component might reflect diminished face-selective neuronal responses to face images with deteriorated structural information. 相似文献
3.
Judit Barabás György Barabás István Szabó Marten Veenhuis Wim Harder 《Archives of microbiology》1988,150(2):105-108
Membrane-bound penicillin-binding proteins (PBPs) of two Streptomyces griseus strains that sporulate well in liquid and solid medium have been investigated during the course of their life-cycle. The PBP patterns were analyzed by sodium dodecylsulphate polyacrylamide-gel electrophoresis and fluorography. One strain (No. 45 H) has only a single band (mol wt: 27,000) in early log phase, and two additional PBPs of higher mol wt (69,000 and 80,000) in the late log phase. The other strain (No. 2682) possessed two bands with mol wts 27,000 and 38,000 which did not change during its vegetative phase. In strain No. 2682, a new PBP with a mol wt of 58,000 appeared in spore membranes while one of those (mol wt 38,000) present in mycelial membranes disappeared. Our results suggest that appearance of the new PBP in the spore may be associated with the sporulation process. The major PBP band (mol wt: 27,000) present in all stages of the life cycle of these strains, may be characteristic of S. griseus while the other PBPs reflect certain stages of the life cycle. A new method was developed for the production of spore protoplasts by consecutive enzymatic treatments.Abbreviation PBP
penicillin-binding protein 相似文献
4.
Mária Wollemann Judit Farkas Géza Tóth Sándor Benyhe 《Journal of neurochemistry》1994,63(4):1460-1465
Abstract: A tritiated heptapeptide, [3 H]Tyr-Gly-Gly-Phe-Met-Arg-Phe ([3 H]Met-enkephalin-Arg6 -Phe7 ), with high specific radioactivity has been synthesized in order to characterize its opioid binding activity to frog brain membrane fractions. The apparent K D value of the radioligand calculated from homologous displacement experiments was 3.4 n M , and the maximal number of specific binding sites was 630 fmol/mg of protein. The K D determined from equilibrium saturation binding studies was found to be 3.6 n M . However, the Hill coefficient was far below unity ( n H = 0.43), which suggests the presence of a second, lower affinity binding site. The presence of this binding component is strengthened by the displacement experiments performed with levorphanol and some other ligands. It is assumed that the lower affinity site has no opiate character. The rank order of potency of the applied ligands in competing reversibly with [3 H]Met-enkephalin-Arg6 -Phe7 binding reflects a κ2 - and/or δ-subtype specificity of the heptapeptide. Binding to a κ1 and/or μ site of opioid receptors is excluded, but the existence of a novel endogenous opiate receptor subtype for Met-enkephalin-Arg6 -Phe7 in frogs cannot be ruled out. The [3 H]Met-enkephalin-Arg6 -Phe7 binding was inhibited by both sodium ions and GppNHp, which suggests the opioid agonist character of the heptapeptide. 相似文献
5.
As previously reported, mitochondrial malate dehydrogenase (MDH) binds to purified complex I of the electron transport system. With conditions used in previous reports, MDH binds even more extensively, but probably predominantly non-specifically, to the matrix side of the inner mitochondrial membrane of submitochodrial particles (SMP). Herein we report experimental conditions for highly specific binding of malate dehydrogenase to complex I within SMP. These conditions permit us to demonstrate NADH channelling from malate dehydrogenase to complex I using the completing reaction test. This test, though not ideal for all situations, has several advantages over the enzyme buffering test previously used. These advantages should facilitate further studies elucidating NADH channeling to complex I from MDH and other dehydrogenases. Independent evidence of NADH channelling to the electron transport chain and the potential advantages of substrate channelling in general are also discussed. Substrate channelling from MDH in particular may be especially beneficial because of the unfavourable equilibrium and kinetics of this enzyme reaction. 相似文献
6.
Miklós Fári István Nagy Márta Csányi Judit Mitykó András Andrásfalvy 《Plant cell reports》1995,15(1-2):82-86
Summary Novel and efficient protocols for plant regeneration and genetic transformation from longitudinally-halved cotyledons ofin vitro raised seedlings in eggplant (Solanum melongena L.) are described. After co-cultivation withAgrobacterium vectors harboring neomycin phosphotransferase (nptll) as selectable marker, transgenic plantlets were regenerated on selective media containing 100 mg/l kanamycin. Transformants were recovered from embryogenic calli induced by 4 mg/l-naphthaleneacetic acid (NAA), and from organogenic calli induced by the addition of 2 mg/l zeatin plus 0.01 mg/l NAA. Nineteen independent transgenic lines were grown to maturity. The structural integrity, expression and sexual transmission of the introduced genes for neomycin phosphotransferase and ß-glucuronidase (gus) were investigated. 相似文献
7.
Imre Mezö János Seprödi Judit Érchegyi István Teplán Magdolna Kovacs Bela Flerkó 《Peptides》1983,4(2):149-151
Inhibitory analogues of luteinizing hormone-releasing hormone (LH-RH) were prepared with formyl-D-Trp1, acetyl-D-Trp1, valeryl-D-Trp1, tartaryl-D-Trp1, diacetyl-tartaryl-D-Trp1, acetyl-Gly1, and acetyl-Sar1 successively replacing the position one in the analogue [D-Trp1, D-p-Cl-Phe2, D-Trp3, D-Phe6, D-Ala10]-LH-RH. The formyl-D-Trp1 and acetyl-D-Trp1 analogues yielded 100% blockade of ovulation at the 10 μg dose; the others were less potent and inhibited ovulation at the 50 μg dose. The inhibitory potency seems to correlate with the polarity of the acyl group. 相似文献
8.
Microstratification of phytoplankton in the large shallow Lake Balaton (Hungary) was studied during a 24 h period. Dissolved O2 showed biological stratification; flagellates exhibited a definite circadian rhythm. In the middle of the investigation a heavy storm broke out which was followed by the disappearance of differences between different layers of water. Storm-induced destratification is described by cluster-analysis. Abundances of dominant species changed differently in connection with the storm. Numbers of Nitzschia sp. increased due to stirring up from the sediment surface. Numbers of single-celled or colony-forming species (Cyclotella comta, Crucigenia quadrata, Coelosphaerium kuetzingianum) practically did not change. Numbers of all the three dominant filamentous species (Aphanizomenon fos-aquae f. klebahnii, Lyngbya limnetica, Planctonema lauterbornii) significantly decreased, which might be attributed to an unknown loss process and was followed by a competitive displacement by algae of small cell size. 相似文献
9.
Videodensitometry based on television technique has been shown to be suitable for recording gel electrophoretic patterns. Its speed of operation is about 60 times as fast as that of conventional densitometers, whereas the patterns recorded are practically the same. 相似文献
10.