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1.
Summary Aluminum extraction from two aluminum-rich fly-ashes by commercial and microbiologically-produced citric acids was tested. Up to 12% Al2O3 of the total was extracted by a 21 hrs1 shaking treatment at 60° C. Extraction efficiency is considerably affected by extracting acid concentration and extraction temperature. The extraction efficiency of microbiologically-produced citric acids was only slightly lower than that of commercial citric acid of equal molarity. 相似文献
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Alterations in the time of X chromosome replication induced by 5-azacytidine in a patient with 48,XXXY/47,XXY 总被引:3,自引:0,他引:3
It has recently been shown that 5-azacytidine (5-azaC) can induce altered replication patterns of the late-replicating X chromosome in normal female cells. This has been demonstrated by bromodeoxyuridine labelling of cells late in the S phase. In the present study the same method was applied to the lymphocytes of a Klinefelter patient (48,XXXY/47,XXY). Significant 5-azaC-induced changes in the replication of the entire inactive X chromosome, from late to early, were found in the lymphocytes of this patient. These results indicate that hypomethylating agents can not only alter the replication of individual bands, but also change the gross replication schedule of multiple inactive X chromosomes in the presence of a Y chromosome. 相似文献
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Cleavage of one specific disulfide bond in papain 总被引:4,自引:0,他引:4
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Summary Plants were grown in gravel beds of basalt or limestone. With the standard nutrient solution yields for the plants grown in the limestone gravel were very much reduced and the plants were chlorotic. This chlorosis and reduced yields remained even if the gravel was acid or water washed beforehand, or if it was pretreated in high phosphate concentrations.High yields, comparable to those obtained in basalt beds were obtained if phosphate and iron were added in small amounts (0.1mM P, 1 mg/1 Fe) at each irrigation. This technique to avoid lime induced chlorosis can be easily and economically accomplished in hydroponics. It proved successful here with lettuce, cucumber, tomato and eggplants. 相似文献
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Hagit Shapira Meir Mouallem Menachem S. Shapiro Yosef Weisman Zvi Farfel 《Human genetics》1996,97(1):73-75
Pseudohypoparathyroidism type Ia (PHP-Ia) is a hereditary disease characterized by resistance to PTH and other hormones that act via cAMP. Patients have deficient activity of Gs, the subunit of the G protein, which couples hormone receptors to stimulation of adenylate cyclase. We describe two new mutations discovered in two sporadic patients with PHP-Ia. Using genomic DNA, we have amplified exons 2–13 of the Gs gene (GNAS1) by PCR, and sequenced the resulting products. Both patients had Albright's hereditary osteodystrophy, resistance to multiple hormones, and deficient Gs activity. In the first patient, a deletion of a C in exon 5 at codon 115 was found. In the second patient, an insertion of a C in exon 10 at codon 267 was detected. Both these heterozygous mutations cause frameshift, and predict decreased production of Gs. This report adds two new Gs mutations to the known ten mutations recently described. 相似文献
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P. Lazarovici D. Shapira V. Pisarev E. Shaaya 《Archives of insect biochemistry and physiology》1984,1(4):409-415
A double-antibody ecdysone-specific radioimmunoassay was used to clarify whether the effects on metamorphosis of the juvenile hormone analogue methoprene are correlated with changes in ecdysteroids level. It appears that a small ecdysteroids peak, 5 days before pupation, is responsible for the transition from inhibition to defective metamorphosis. Study of the changes in ecdysteroid titer in last-instar larvae treated with the JHA 2 days prior to the appearance of the above small ecdysteroids' peak showed an immediate reduction in ecdysteroid level, followed by cyclic, successively reduced titer for about 20 days. After this period the larvae ceased to feed and entered to a diapauselike stage which ended in the death of the larvae. A similar effect on ecdysteroid titer and developmental arrest was exhibited by JHA-treated first-instar larvae. The mechanism of the interactions between JHA and ecdysteroid level deserves further investigation. 相似文献
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Abstract— Chromatography of myelin basic protein (BP) on carboxymethylcellulose gives a pattern of multiple components, of which three are major. Component 1 is considered the unmodified species of BP while component 2 has been found to be modified primarily by deamidation and component 3 by phosphorylation (Chou et al., 1976). 3 3 The numbering system for the components is that used by DEIBLER & MARTENSON (1973) for guinea pig BP and is preferred over the reverse system of numbering used by CHOU et al. (1976); i.e. components 1, 2 and 3 of DEIBLER & MARTENSON (1973) are the same as components 6, 5 and 4 of CHOU et al. (1976), respectively.
In contrast to BP prepared from tissue delipidated in the standard fashion in chloroform–methanol (CM powder), BP prepared from tissue delipidated first in acetone and then in chloroform–methanol (ACM powder) gave an elution pattern on carboxymethylcellulose characterized by a decrease in component 1 and an increase in the earlier eluting, less basic components. Studies with radiolabelled component 1 showed that this difference in elution patterns was due to the partial conversion of component 1 to less basic components during the extraction of ACM powder at neutral pH. The components derived from component 1 (D2, D3 and D4) were then isolated and subjected to tryptic peptide map analyses and determination of their carboxy-terminal arginine content and content of phosphorus. None of the derived components contained phosphorus but tryptic peptide map analyses did show the presence of two minor peptides, T14M2 and T20M, previously found in component 2 from CM powder and considered to be the deamidation products of their parent peptides T14 and T20 (Chou et al., 1976). In addition components D3 and D4 were shown to have lost appreciable arginine from their carboxy-termini. Since none of the efforts to reduce enzyme activity in vitro had any appreciable effect on components 2 and 3 it was concluded that phosphorylation probably occurs exclusively in vivo, that deamidation occurs both in vivo and in vitro and that loss of carboxy-terminal arginine occurs exclusively in vitro. 相似文献
In contrast to BP prepared from tissue delipidated in the standard fashion in chloroform–methanol (CM powder), BP prepared from tissue delipidated first in acetone and then in chloroform–methanol (ACM powder) gave an elution pattern on carboxymethylcellulose characterized by a decrease in component 1 and an increase in the earlier eluting, less basic components. Studies with radiolabelled component 1 showed that this difference in elution patterns was due to the partial conversion of component 1 to less basic components during the extraction of ACM powder at neutral pH. The components derived from component 1 (D2, D3 and D4) were then isolated and subjected to tryptic peptide map analyses and determination of their carboxy-terminal arginine content and content of phosphorus. None of the derived components contained phosphorus but tryptic peptide map analyses did show the presence of two minor peptides, T14M2 and T20M, previously found in component 2 from CM powder and considered to be the deamidation products of their parent peptides T14 and T20 (Chou et al., 1976). In addition components D3 and D4 were shown to have lost appreciable arginine from their carboxy-termini. Since none of the efforts to reduce enzyme activity in vitro had any appreciable effect on components 2 and 3 it was concluded that phosphorylation probably occurs exclusively in vivo, that deamidation occurs both in vivo and in vitro and that loss of carboxy-terminal arginine occurs exclusively in vitro. 相似文献
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