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91.
Prashanth Sirigeri Jois 《Biochemical and biophysical research communications》2010,394(4):1036-1041
Bovine BSP5 belongs to the Binder of SPerm (BSP) family. BSP5 plays a role in the bovine sperm capacitation by promoting cholesterol and phospholipid efflux. The variable N-terminal part in the BSP proteins is the uncharacterized region with no known function. Full-length, N-terminal part, and individual fibronectin type II domains of bovine BSP5 were cloned, expressed and purified from Escherichia coli. His-S tagged N-terminal part showed large variation in migration on SDS-PAGE in comparison to other constructs. Using mass spectrometry it was demonstrated that the His-S-N-terminal part has the expected molecular mass (13 kDa). The recombinant N-terminal part was sensitive to E. coli endogenous proteases during purification. Denaturing purification involving boiling lysis of cells was carried out, as the protein was thermostable. The His-S-N-terminal part lacked structure as determined by CD analysis. Bioinformatics analyses confirmed that the N-terminal part of bovine BSP5 is intrinsically disordered. In addition, bioinformatics analysis indicated that rabbit BSP and multiple forms of BSP proteins of bovine and equine species possess partially or completely disordered N-terminus. The conservation of disorder at the N-terminus in BSP members belonging to different species suggests a role in biological process such as sperm capacitation and/or sperm-egg interactions. 相似文献
92.
In Callithrix jacchus the urinary excretion of hydroxypregnanolone (5 alpha-pregnane-3 alpha, 7 alpha-diol-20-one) shows a luteal rise during the ovulatory cycle. This progesterone metabolite can therefore be used as an indication of ovulation, implantation, and subsequently for the persistence of the pregnancy. The excretion can be monitored by high performance thin-layer chromatography (HPTLC) and postchromatographic derivatization after enzymatic hydrolysis of the conjugate. Profiles of urinary hydroxypregnanolone levels are presented and correlated with luteinizing hormone excretion. The method is noninvasive and therefore suited for long-term studies in these monkeys. 相似文献
93.
《Saudi Journal of Biological Sciences》2020,27(6):1573-1579
Supplementation of the growing substrate by nitrogenous additives has been known to improve the production of oyster mushroom (Pleurotus ostreatus (Jacq. ex Fr.) P. Kumm. (1871)). However, the application of nano-additives has not been reported in such cultivation yet. The study investigated the effect of nano-urea added in two different doses (3 g and 5 g per kg substrate), once (at spawning or after first flush) or twice (at spawning and after first flush) to the growing substrate consisting of wheat straw and spent oyster substrate (1:1, w/w). Results showed that the application of nano-urea once has induced the highest number of mushroom flushes (four flushes) despite the dose applied. Contrarily to early findings, where high doses of nitrogen have caused inhibition of mushroom growth and production, nano-urea application has had better effects when applied twice. With 5 g/kg, it induced the shortest period between the first and the third flush (15 days). With 3 g/kg, it resulted in the highest biological and economic yields at the third flush (332.7 g/bag and 283.1 g/bag respectively), in total (973.4 g/bag and 854.0 g/bag respectively), the highest biological efficiency (109.6%), and pileus diameter/stipe length ratio (2.8). Experimental findings of the current study may be potentially applied at commercial scale. 相似文献
94.
Yoshifumi Tanaka 《Ocean Development & International Law》2013,44(2):129-149
Attention is increasingly being given to genetic resources in the deep seabed beyond the limits of national jurisdiction owing to their considerable potential scientific and economic value. At the same time, there are concerns that the increased demand for these genetic resources may result in their unsustainable collection or even in the extinction of species in the deep seabed. At present there is no specific legal framework governing these resources in international law. Thus, this article explores the relevant rules of international law applicable to the conservation and sustainable use of genetic resources in the deep seabed. 相似文献
95.
This study evaluated the gait stability, variability, and complexity of healthy young adults on inclined surfaces. A total of 49 individuals walked on a treadmill at their preferred speed for 4 min at inclinations of 6%, 8%, and 10% in upward (UP) and downward (DOWN) conditions, and in horizontal (0%) condition. Gait variability was assessed using average standard deviation trunk acceleration between strides (VAR), gait stability was assessed using margin of stability (MoS) and maximum Lyapunov exponent (λs), and gait complexity was assessed using sample entropy (SEn). Trunk variability (VAR) increased in the medial-lateral (ML), anterior-posterior, and vertical directions for all inclined conditions. The SEn values indicated that movement complexity decreased almost linearly from DOWN to UP conditions, reflecting changes in gait pattern with longer and slower steps as inclination increased. The DOWN conditions were associated with the highest variability and lowest stability in the MoS ML, but not in λs. Stability was lower in UP conditions, which exhibited the largest λs values. The overall results support the hypothesis that inclined surfaces decrease gait stability and alter gait variability, particularly in UP conditions. 相似文献
96.
In soil micromorphology fissures are considered in vertical sections. To get information about the properties of the soil the joint distribution of spatial direction and width of these fissures is of interest. The fissures are mathematically generalized to flat bodies which are defined as stationary weighted surface processes with the weight “thickness”. In a typical point of the surface process suitable, joint parametric distributions of direction and thickness are assumed. The parameters have to be estimated from measurements on vertical sections which are taken from the soil. On these sections only a visible thickness and a visible angle can be observed. The joint distribution of these variables can be expressed by the joint distribution of spatial direction and thickness with the same parameters and in this indirect way the parameters can be estimated. The paper describes how to randomize the vertical section and how to measure the visible variables on the sections. The Chi-Square method is proposed for the parameter estimation. Further it is discussed how to derive good starting values for the numerical procedure. All this is demonstrated in a simulation study using the Bingham-Mardia distribution for the direction and the lognormal distribution for the thickness including a way to correlate the mean thickness and the direction. Finally an application in soil micromorphology is demonstrated for one soil horizon. 相似文献
97.
Detailed palynological studies in two adjoining French Pyrenean valleys, complemented by the study of archives, demonstrate that under similar climatic conditions, the forest history of each valley from the Bronze Age to present time was essentially determined by socio-economical constraints, possibly modified by natural characteristics such as topography. The studies show why the expansion of Fagus (beech) at c. 4000 B.P. was asynchronous on the northern slope of the Pyrenees and emphasize the effects of the human impact on the recent lowering of the tree-line.A contribution to the 8th IPC, Aix-en-Provence, 1992 相似文献
98.
《Journal of biomechanics》2014,47(16):3862-3867
The aim of this study was to test the hypothesis that running at fixed fractions of Froude (Nfr) and Strouhal (Str) dimensionless numbers combinations induce dynamic similarity between humans of different sizes. Nineteen subjects ran in three experimental conditions, (i) constant speed, (ii) similar speed (Nfr) and (iii) similar speed and similar step frequency (Nfr and Str combination). In addition to anthropometric data, temporal, kinematic and kinetic parameters were assessed at each stage to measure dynamic similarity informed by dimensional scale factors and by the decrease of dimensionless mechanical parameter variability. Over a total of 54 dynamic parameters, dynamic similarity from scale factors was met for 16 (mean r=0.51), 32 (mean r=0.49) and 52 (mean r=0.60) parameters in the first, the second and the third experimental conditions, respectively. The variability of the dimensionless preceding parameters was lower in the third condition than in the others. This study shows that the combination of Nfr and Str, computed from the dimensionless energy ratio at the center of gravity (Modela-r) ensures dynamic similarity between different-sized subjects. The relevance of using similar experimental conditions to compare mechanical dimensionless parameters is also proved and will highlight the study of running techniques, or equipment, and will allow the identification of abnormal and pathogenic running patterns. Modela-r may be adapted to study other abilities requiring bounces in human or animal locomotion or to conduct investigations in comparative biomechanics. 相似文献
99.
《Biocatalysis and Biotransformation》2013,31(1-4):1-30
Peptides, and oligosaccharides and glycosides, can be synthesised by making use of the ‘reverse hydrolytic activity’ of proteases and glycosidases respectively. In applying these enzymes to the practical synthesis of these classes of compound, several factors need to be considered, namely the need to shift the rate-determining step through the use of activated substrates, the need to minimise competing hydrolysis of these and the need to minimise hydrolysis of the products. In spite of these problems, the enzymatic methods have many attractive features, not least amongst which is the absolute control of stereochemistry in acyl transfer and glycosyl transfer respectively. 相似文献
100.