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1.
In this study, the aim has been to characterize the profiles of progesterone, estradiol and follicular changes during postpartum period from parturition to first postpartum ovulation. Jugular venous blood was taken daily for progesterone and estradiol assay until first postpartum ovulation. The diameters of the follicles of the ovaries were recorded. The mean progesterone and estrogen concentrations markedly decreased (p<0.05) during the 48h after parturition. No correlation was observed between estradiol concentrations and the diameter of the largest follicle whereas a negative correlation was present between the number of follicles smaller than 20mm and the number of follicles larger than 20mm on the third and fourth days after postpartum.  相似文献   
2.
We describe a modification and post‐functionalization technique for a donor–acceptor–donor type monomer; 6‐(4,7‐bis(2,3‐dihydrothieno[3,4‐b][1,4]dioxin‐5‐yl)‐2H‐benzo[d][1,2, 3]triazol‐2‐yl)hexan‐1‐amine. Folic acid was attached to the fluorescent structure. The conjugation was confirmed via NMR and Fourier transform infrared analyses. Cytotoxicity was investigated and the comparison of association of targeted monomeric structures in tumor cells was monitored via fluorescence microscopy. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:952–959, 2014  相似文献   
3.
Zinc deficiency as a critical problem in wheat production in Central Anatolia   总被引:19,自引:0,他引:19  
In a soil and plant survey, and in field and greenhouse experiments the nutritional status of wheat plants was evaluated for Zn, Fe, Mn and Cu in Central Anatolia, a semi-arid region and the major wheat growing area of Turkey.All 76 soils sampled in Central Anatolia were highly alkaline with an average pH of 7. 9. More than 90% of soils contained less than 0.5 mg kg-1 DTPA-extractable Zn, which is widely considered to be the critical deficiency concentration of Zn for plants grown on calcareous soils. About 25% of soils contained less than 2.5 mg kg-1 DTPA-extractable Fe which is considered to be the critical deficiency concentration of Fe for plants. The concentrations of DTPA-extractable Mn and Cu were in the sufficiency range. Also the Zn concentrations in leaves were very low. More than 80% of the 136 leaf samples contained less than 10 mg Zn kg–1. By contrast, concentrations of Fe, Mn and Cu in leaves were in the sufficient range.In the field experiments at six locations, application of 23 kg Zn ha-1 increased grain yield in all locations. Relative increases in grain yield resulting from Zn application ranged between 5% to 554% with a mean of 43%. Significant increases in grain yield (more than 31%) as a result of Zn application were found for the locations where soils contained less than 0.15 mg kg-1 DTPA-extractable Zn.In pot experirnents with two bread (Triticum aestivum, cvs. Gerek-79 and Kirac-66) and two durum wheats (Triticum durum, cvs. Kiziltan-91 and Kunduru-1149), an application of 10 mg Zn kg-1 soil enhanced shoot dry matter production by about 3.5-fold in soils containing 0.11 mg kg-1 and 0.15 mg kg-1 DTPA-extractable Zn. Results from both field observations and greenhouse experiments showed that durum wheats were more susceptible to Zn deficiency than the bread wheats. On Zn deficient soils, durum wheats as compared to bread wheats developed deficiency symptoms in shoots earlier and to a greater extent, and had lower Zn concentration in shoot tissue and lower Zn content per shoot than the bread wheats.The results presented in this paper demonstrate that (i) Zn deficiency is a critical nutritional problem in Central Anatolia substantially limiting wheat production, (ii) durum wheats possess higher sensitivity to Zn deficient conditions than bread wheats, and (iii) wheat plants grown in calcareous soils containing less than 0.2 mg kg-1 DTPA-extractable Zn significantly respond to soil Zn applications. The results also indicate that low levels of Zn in soils and plant materials (i.e. grains) could be a major contributing factor for widespread occurrence of Zn deficiency in children in Turkey, whose diets are dominated by cereal-based foods.  相似文献   
4.
The effect of the zinc (Zn) nutritional status on the rate of phytosiderophore release was studied in nutrient solution over 20 days in four bread wheat (Triticum aestivum cvs. Kiraç-66, Gerek-79, Aroona and Kirkpinar) and four durum wheat (Triticum durum cvs. BDMM-19, Kunduru-1149, Kiziltan-91 and Durati) genotypes differing in Zn efficiency.Visual Zn deficiency symptoms, such as whitish-brown necrosis on leaves and reduction in plant height appeared first and more severe in Zn-inefficient durum wheat genotypes Kiziltan-91, Durati and Kunduru-1149. Compared to the bread wheat genotypes, all durum wheat genotypes were more sensitive to Zn deficiency. BDMM-19 was the least affected durum wheat genotype. Among the bread wheat genotypes, Kirkpinar was the most sensitive genotype. In all genotypes well supplied with Zn, the rate of phytosiderophore release was very low and did not exceed 1 mol 32 plants-1 3h-1, or 0.5 mol g-1 root dry wt 3h-1. However, under Zn deficiency, with the onset of visual Zn deficiency symptoms, the release of phytosiderophores was enhanced in bread wheat genotypes up to 7.5 mol 32 plants-1 3h-1, or 9 mol g-1 root dry wt 3h-1, particularly in Zn-efficient Kiraç-66, Gerek-79 and Aroona. In contrast to bread wheat genotypes, phytosiderophore release in Zn-deficient durum wheat genotypes remained at a very low rate. Among the durum wheat genotypes BDMM-19 had highest rate of phytosiderophore release. HPLC analysis of root exudates showed that 2-deoxymugineic acid (DMA) is the dominating phytosiderophore released from roots of Zn-efficient genotypes. In root extracts concentration of DMA was also much higher in Zn-efficient than in inefficient genotypes. The results demonstrate that enhanced synthesis and release of phytosiderophores at deficient Zn supply is involved in Zn efficiency in wheat genotypes. It is suggested that the expression of Zn efficiency mechanism is causally related to phytosiderophore-mediated enhanced mobilization of Zn from sparingly soluble Zn pools and from adsorption sites, both in the rhizosphere and plants.  相似文献   
5.
In the study of hydrolysis of tributyrin by the lipase of Candida cylindracea, it is shown that initial rates of hydrolysis are directly proportional to the amount of enzyme adsorbed at the substrate-water interface. As a consequence of understanding the role of the physical state of the substrate in aqueous reaction media, it was hypothesized that the inclusion of synthetic (nonsubstrate) surfaces into the reaction media may enhance the hydrolysis rate of simple liquid lipids which are partly soluble in water, like triacetin. Nonpolar n-hydrocarbons having 5-11 carbon atoms were used to create interfaces in the hydrolysis of triacetin in the soluble range. All of the C(5)-C(11) hydrocarbons showed an activating effect. For quantitative evaluation of the effects of n-hydrocarbons, n-heptane was chosen as the model n-hydrocarbon. Interrelations between the reaction kinetics and adsorption of the enzyme at the n-heptane-water interface were experimentally determined by the use of the same in-line filtration device used for the tributyrin-water system. At 35 degrees C and pH 6 the relative values of the rate constants for the decomposition of enzyme-interface-substrate complexes were calculated as 12 and 1 for the tributyrin and n-heptane-triacetin systems, respectively. The nature of activation at the solvent surfaces were accounted for by a kinetic model which assumes simultaneous adsorption of enzyme and triacetin molecules at the n-heptane-water interface. Making use of the proposed model, the value of a the apparent Michaelis constant for the soluble triacetin-n-heptane system at constant n-heptane concentration, 2 vol %, was calculated as 0.044 mol/L.  相似文献   
6.
7.
Where do the bottlenecks for information and attention lie when our visual system processes incoming stimuli? The human visual system encodes the incoming stimulus and transfers its contents into three major memory systems with increasing time scales, viz., sensory (or iconic) memory, visual short-term memory (VSTM), and long-term memory (LTM). It is commonly believed that the major bottleneck of information processing resides in VSTM. In contrast to this view, we show major bottlenecks for motion processing prior to VSTM. In the first experiment, we examined bottlenecks at the stimulus encoding stage through a partial-report technique by delivering the cue immediately at the end of the stimulus presentation. In the second experiment, we varied the cue delay to investigate sensory memory and VSTM. Performance decayed exponentially as a function of cue delay and we used the time-constant of the exponential-decay to demarcate sensory memory from VSTM. We then decomposed performance in terms of quality and quantity measures to analyze bottlenecks along these dimensions. In terms of the quality of information, two thirds to three quarters of the motion-processing bottleneck occurs in stimulus encoding rather than memory stages. In terms of the quantity of information, the motion-processing bottleneck is distributed, with the stimulus-encoding stage accounting for one third of the bottleneck. The bottleneck for the stimulus-encoding stage is dominated by the selection compared to the filtering function of attention. We also found that the filtering function of attention is operating mainly at the sensory memory stage in a specific manner, i.e., influencing only quantity and sparing quality. These results provide a novel and more complete understanding of information processing and storage bottlenecks for motion processing.  相似文献   
8.
ABSTRACT

The aim of this study was to identify factors affecting dog owners’ breed choices at the time of acquisition and whether they were associated with socio-demographics and dog-related variables (size, temperament, function). Answers (n = 581) to a questionnaire formed the data for this study. In order to determine which factors affected breed choice, a principal component analysis (PCA) was conducted. This revealed that owners were influenced by adaptation ability, social influence, working expectation, and breed characteristics at the time of dog acquisition, all of which explained 54.8% of the total variance. In order to determine the relationships between these influences, demographics, and dog-related factors, both univariate and multiple regression analyses were conducted. It was found that gender, education level, housing type, number of children, having another pet, and owners’ self-classification of professionalism were significantly associated with the factors affecting owners’ choices. Furthermore, dog-related factors were found to be a better predictor than the demographics of the owner in determining the factors affecting breed choices.  相似文献   
9.
Effects of light regimes on anther culture response in bread wheat   总被引:3,自引:0,他引:3  
This experiment was initiated to further test the effects of light regimes during callus induction and plant regeneration on anther culture response of spring wheat (Triticum aestivum L.). Spring wheat cultivars 'Edwall' and 'WA 7176' with high callus induction from anther culture but low green plant production were used. Different gro-lux light and dark regimes during callus induction, and gro-lux light and fluorescent light regimes during plant regeneration were used. Callus induction decreased significantly at relatively high light intensity (315 μmol m−2 s−1) applied at any period of culture when compared to continuous dark. Light regimes used continuously and from the 15th to the last day of callus induction also had a significant negative effect on plant regeneration compared to continuous dark and light application in the first half of callus induction. During plant regeneration, '15 day dark + 7 day gro-lux light' significantly increased plant regeneration compared to both 'gro-lux' and 'fluorescent light' regimes. Light regimes during both callus induction and plant regeneration and their interaction effects were found to be highly significant on green plant proportion and green plant yield. 'Continuous light' application during callus induction increased green plant proportion more than other applications in contrast to its negative effect on plant regeneration. During plant regeneration, '15 day dark + 7 day gro-lux light' had the higher green plant proportion compared to only 'fluorescent light' and only 'gro-lux light'. The highest green plant yields were obtained from '15 day dark + 7 day gro-lux light' during plant regeneration in combination with either 'continuous dark' or 'continuous light' regimes during callus induction. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   
10.
Cakmak  I.  Ekiz  H.  Yilmaz  A.  Torun  B.  Köleli  N.  Gültekin  I.  Alkan  A.  Eker  S. 《Plant and Soil》1997,188(1):1-10
Field and greenhouse experiments were carried out to study the response of rye (Secale cereale L. cv. Aslim), triticale (× Triticosecale Wittmark. cv. Presto), two bread wheats (Triticum aestivum L, cvs. Bezostaja-1 and Atay-85) and two durum wheats (Triticum durum L. cvs. Kunduru-1149 and C-1252) to zinc (Zn) deficiency and Zn fertilization in severely Zn-deficient calcareus soils (DTPA-Zn=0.09 mg kg-1 soil). The first visible symptom of Zn deficiency was a reduction in shoot elongation followed by the appearance of whitish-brown necrotic patches on the leaf blades. These symptoms were either absent or only slight in rye and triticale, but occurred more rapidly and severely in wheats, particularly in durum wheats. The same was true for the decrease in shoot dry matter production and grain yield. For example, in field experiments at the milk stage, decreases in shoot dry matter production due to Zn deficiency were absent in rye, and were on average 5% in triticale, 34% in bread wheats and 70%, in durum wheats. Zinc fertilization had no effect on grain yield in rye but enhanced grain yield of the other cereals. Zinc efficiency of cereals, expressed as the ratio of yield (shoot dry matter or grain) produced under Zn deficiency compared to Zn fertilization were, on average, 99% for rye, 74% for triticale, 59% for bread wheats and 25% for durum wheats.These distinct differences among and within the cereal species in susceptibility to Zn deficiency were closely related to the total amount (content) of Zn per shoot, but not with the Zn concentrations in shoot dry matter. For example, the most Zn-efficient rye and the Zn-inefficient durum wheat cultivar C-1252 did not differ in shoot Zn concentration under Zn deficiency, but the total amount of Zn per whole shoot was approximately 6-fold higher in rye than the durum wheat. When Zn was applied, rye and triticale accumulated markedly more Zn both per whole shoot and per unit shoot dry matter in comparison to wheats.The results demonstrate an exceptionally high Zn efficiency of rye and show that among the cereals studied Zn efficiency declines in the order rye>triticale>bread wheat>durum wheat. The differences in expression of Zn efficiency are possibly related to a greater capacity of efficient genotypes to acquire Zn from the soil compared to inefficient genotypes.  相似文献   
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