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91.
He Xi Jiang Yifan Chen Sumei Chen Fadi Chen Feng 《Journal of Plant Growth Regulation》2023,42(2):1144-1157
Journal of Plant Growth Regulation - Terpenoids are a class of structurally diverse natural products involved in various plant biological processes. Their primary function is believed to provide... 相似文献
92.
Résumé ChezCalotermes flavicollis, la formation des sexués néoténiques est plus facile, ou plus rapide, dans le sexe femelle que dans le sexe mâle.Les sexués femelles montrent un pouvoir inhibiteur à l'égard des individus femelles; les sexués mâles inhibent les mâles de façon moins complète; la stabilisation complète peut être obtenue dans les élevages unisexués, formés uniquement de mâles ou de femelles.La régulation du nombre des néoténiques ne se fait pas de la même façon dans les élevages et dans les élevages . Dans les premiers, 2 néoténiques subsistent, quelquefois 3; dans les seconds ne persiste qu'un seul néoténique , rarement deux.Ces résultats mettent en lumière le rôle différent joué par les mâles et les femelles dans les sociétés de Termites. 相似文献
93.
C Heiss T Keller U Wehr A Mohr D Lommel Ch Meyer W A Rambeck R Schnettler 《Biomedizinische Technik》2004,49(10):282-289
This study analyzes the qualification of biochemical markers in the diagnosis of osteoporosis and evaluates the potential of a multiparametric classification of premenopausal and non-osteoporotic as well as osteoporotic postmenopausal women, which is based on biochemical marker profiles. For this evaluation data of 29 women in the age between 28-74 years were used. The classification of osteoporosis was done by the trabecular density of the lumbar spine using qCT-measurements. The biochemical markers of formation and resorption AP, bAP, OC, ucOC, PICP, PYD, DPD, NTX, BSP and vitamin K were analyzed on day 1 and 42 in all patients. For vitamin K we found significant distribution differences between non-osteoporotic and osteoporotic women (p<0.005). The crosslinks PYD and DPD showed weakly significant differences. All other parameters exhibited non-significant results. Vitamin K acted with a sensitivity of 64% and a specificity of 82%. The used multiparameter classification process improved sensitivity and specificity considerably. The parameter profiles of OC/PYD, vitamin K/PYD and vitamin K/bAP revealed the highest sensitivities with specificities of more than 82%. 相似文献
94.
The reversible hydrolysis of maltose to glucose by immobilized glucoamylase entrapped in spherical solid particles is studied theoretically. For this purpose a known kinetic model taking into account these reversible reactions and the competitive synthesis of iso-maltose was adopted. The mass transfer limitations in the bulk liquid and in the pores of the particles containing the enzyme are considered, using Fick's law. On the basis of mathematical modelling the optimum conditions for biocatalyst performance are established. An appropriate combination of particle size and initial substrate concentration may lead to reduction of undesirable mass transfer resistance and therefore product inhibition and to an improved selectivity of the biocatalyst with respect of glucose formation.List of Symbols
C
i
kmoles/m3
current concentration ofi-th component along the radius
-
C
oi
kmoles/m3
bulk concentration ofi-th component
-
C
i
*
kmoles/m3
concentrations ofi-th component on the pellet surface
-
D
si
,D
i
m2/s
internal and molecular diffusion coefficient ofi-th component
-
W
M
kmoles/m3·s
reaction rate of maltose hydrolysis
-
W
IM
kmoles/m3·s
reaction rate of iso-maltose formation
-
W
G
kmoles/m3·s
reaction rate of glucose production
-
R
0
m
pellet radius
-
r m
current radius of the pellet
-
t s
time coordinate
-
r
0
ratio of the time step to the square of the radial coordinate
-
Re
Reynolds number =w·R/v
-
Sc
Schmidt number =v/D
-
Bi
Biot number = R/D
-
A
j
,B, C
j
coefficients in the system of linear equations, Eq. (8)
-
X
i
dimensionless degree of transformation
-
NR
number of independent reactions
-
N
number of division sections of the pellet radius
-
G kmoles/m3
concentration of glucose
-
M kmoles/m3
concentration of maltose
-
IM kmoles/m3
concentration of isomaltose
-
K
m
kmoles/m3
Michaelis constant
-
V
max kmoles/m3·s
maximum reaction rate in Eq. (6)
-
K
i
kmoles/m3
inhibition constant
-
K
1eq
,K
2eq
equilibrium constants in Eq. (6)
-
, h
steps along the time and radial coordinate in the pellet
-
m/s
mass transfer coefficient
-
dimensionless radius of the pellet
-
computation accuracy
Indices
i
number of reaction component
-
j
index along the radius of the pellet
-
k
index along the time coordinate
This work was accomplished with thanks to the financial support of the Bulgarian National Fund for Scientific Investigations —Grant No. MU-1-BE/93. 相似文献
95.
96.
97.
Rosemarie Weikard T. Goldammer Ch. Kühn W. Barendse M. Schwerin 《Mammalian genome》1997,8(11):836-840
A methodical strategy for the isolation of microsatellite markers specific for targeted regions of bovine chromosomes is
presented. The procedure involves directed microdissection of one defined subchromosomal area, its DOP-PCR-amplification and
cloning. With this approach, a library specific to the BTA 6q21-31 chromosomal region was constructed. Eleven unique microsatellite-containing
sequences were isolated, converted into sequence-tagged microsatellite sites, and characterized concerning their species-specific
origin. Seven primer pairs generated bovine-specific PCR products and provided a set of microsatellite markers that generally
revealed high informativity in the HF breed. Linkage analysis assigned six of them to their predefined subchromosomal origin
on BTA 6 corresponding to the specific rehybridization signal of the DOP-PCR product generated from the microdissected chromosome
area 6q21-31. The results underline the usefulness of the BTA 6q21-31 library for targeted isolation of unique sequences that
are specific for the dissected chromosomal region as demonstrated here by the isolation of microsatellite markers.
Received: 27 March 1997 / Accepted: 14 July 1997 相似文献
98.
Host-cell cyclophilin is important for the intracellular replication of Leishmania major 总被引:1,自引:0,他引:1
A. Hoerauf Ch. Rascher R. Bang A. Pahl W. Solbach K. Brune M. Röllinghoff & H. Bang 《Molecular microbiology》1997,24(2):421-429
The antiparasitic effects of cyclosporin A were examined in leishmanial infection by analysing the role of CsA-binding proteins (cyclophilins) in the host–parasite interaction. We hypothesized that the leishmanicidal effects of CsA on Leishmania major infected macrophages might be mediated through a cyclophilin of either the parasite or the host cell. Two cyclophilins (20 and 22 kDa) were purified from L. major parasites and N-terminally sequenced. Although enzyme activity of these cyclophilins was inhibited by CsA, pretreatment of L. major parasites with CsA did not result in reduction of a subsequent macrophage infection, arguing against a role of L. major cyclophilins as infectivity potentiators. However, host-cell cyclophilin A (CypA) was found to be critically involved in the intracellular replication of L. major parasites in murine macrophages. An antisense oligonucleotide to murine CypA was constructed and added to cultures of peritoneal macrophages prior to infection with L. major parasites. This treatment strongly reduced the expression of CypA in macrophages and resulted in the inhibition of the intracellular replication of L. major amastigotes. These data indicate that interaction of amastigotes with host-cell cyclophilin is an important part of the intracellular replication machinery of L. major and define, for the first time, a direct involvement of a cyclophilin in the survival strategies of an intracellular parasite. 相似文献
99.
The Prisoner''s Dilemma has become a paradigm for the evolution of altruistic behaviour. Here we present results of numerical simulations of the infinitely iterated stochastic simultaneous Prisoner''s Dilemma considering players with longer memory, encounters of more than two players as well as different pay-off values. This provides us with a better foundation to compare theoretical results to experimental data. We show that the success of the strategy Pavlov, regardless of its simplicity, is far more general by having an outstanding role in the iterated N-player N-memory Prisoner''s Dilemma. Besides, we study influences of increased memory sizes in the iterated two-player Prisoner''s Dilemma, and present comparisons to results of experiments with first-year students. 相似文献
100.
囊萼紫草属与滇紫草属花粉形态比较研究 总被引:3,自引:1,他引:2
本文借助光学显微镜和扫描电镜研究了囊萼紫草属3种和滇紫草属12种植物的花粉形态。囊萼紫草属的花粉为哑铃形或茧形,中等大小,P/E比为1.6一1.67,三孔沟,内孔横长;具小刺状纹饰。滇紫草属的花粉为近长球形或近卵球形,P/E为l—1.23;三孔沟或三合沟孔,内孔一般纵长,具皱波状纹饰,在皱波上具密集的小瘤或微颗粒。从花粉形态的角度,本文支持把囊萼紫草属从滇紫草属(广义)中分离出来的观点。值得注意的是,在滇紫草属的花粉中首次观察到了一种比较少见且特化的花粉即单极三合沟孔的花粉。 相似文献