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61.
62.
The risk posed by the quantity of heavy metal lead present in Ca supplements is of grave concern. Some lead levels have been
measured up to the extent of regulatory limit set by the United States. Calcium supplements inevitably get contaminated with
lead as both are naturally occurring elements having the same charge density. Therefore, it is imperative to indicate the
level of this toxic metal in these supplements in order to create awareness among consumers. The calcium in the supplements
is derived from natural as well as synthetic/refined sources (chelated or non-chelated). In this study, a sophisticated analytical
technique, atomic absorption spectrometer (both with FAAS and GFAAS modes of atomization), was used for the purpose of analyzing
Pb contents in 27 commonly used Ca supplements manufactured by different national and multinational companies. The daily intake
of lead through these supplements was calculated. Only 10% of the calcium supplements analyzed met the criteria of acceptable
Pb levels (1.5 μg/daily dose) in supplements/consumer products set by the United States. It was also found that Pb intake
was highest in chelated calcium supplements whereas lowest through calcium supplements with vitamin D formulation. The Pb
concentration in calcium supplements was significantly increased (p < 0.001) according to their composition. In order to validate our results from the study conducted, IAEA-certified reference
material (animal bone, H-5) was analyzed for Pb levels. The limit of detection of the method used was 0.05 μg/g and a 95%
lead recovery of IAEA-certified reference material (animal bone, H-5). 相似文献
63.
Estrogens and androgens inhibit association of RANKL with the pre‐osteoblast membrane through post‐translational mechanisms 下载免费PDF全文
64.
Khalid M. Chraibi B Jean-Claude Castelle Alain Latche Jean-Paul Roustan Jean Fallot 《Plant cell reports》1992,10(12):617-620
We describe here a liquid culture system for the regeneration of shoots at high frequencies from mature cotyledon tissues of three genotypes of sunflower (Helianthus annuus L.) one of which had previously been found to be recalcitrant to regeneration when cotyledons were cultured on solid medium. Cotyledons were excised from 2-day-old seedlings and incubated in liquid Murashige and Skoog's modified medium supplemented with 5.4 M naphthaleneacetic acid (NAA) and 4.4 M benzylaminopurine (BAP). After two weeks in culture, the whole upper surface of regenerating explants was covered with green shootlets. The percentages of regenerating explants of three genotypes varied between 60 and 70%, and the number of shoots per regenerating explant was highly increased. The shootlets were transferred to solid Murashige and Skoog's medium allowing shoot development, then to rooting medium. Rooted plantlets were successfully acclimatized and gave fertile plants. The role of liquid medium culture in the induction of sunflower regeneration is discussed.Abbreviations BAP
6-benzylaminopurine
- NAA
1-naphthaleneacetic acid
- IAA
indole-3-acetic acid
- IBA
indole-3-butyric acid 相似文献
65.
Muhammad Shakeel Farhat Jabeen Rehana Iqbal Abdul Shakoor Chaudhry Sadia Zafar Muhammad Ali Muhammad Saleem Khan Adeel Khalid Samina Shabbir Muhammad Saleem Asghar 《Biological trace element research》2018,182(1):57-69
This study assessed the protective effects of Cinnamomum cassia (cinnamon) bark extract in rats exposed to titanium dioxide nanoparticles or titanium dioxide bulk salt. For in vivo evaluation of the ameliorative role of the cinnamon extract, the experimental groups were orally administered with the cinnamon extract at different dose levels (50 or 100 or 150 mg/kg bodyweight) along with the subcutaneous injections of 150 mg/kg bodyweight titanium dioxide nanoparticles or titanium dioxide bulk salt. The extract showed significant ameliorative role on the antioxidant system in response to elevated levels of titanium dioxide nanoparticles or titanium dioxide bulk salt-induced oxidative stress. It aided in the recovery of the antioxidant system as well as protective role in histological damages and some haematological parameters in the rat liver treated with titanium dioxide nanoparticles or titanium dioxide bulk salt. 相似文献
66.
Khalid M. Chraibi B. Alain Latche Jean-Paul Roustan Jean Fallot 《Plant cell reports》1991,10(4):204-207
The effects of CoCl2, AgNO3 and ethylene released by exogenous 2-chloroethylphosphonic acid (Ethephon), were studied on shoot regeneration from cotyledons of Helianthus annuus cv. E8206R, a poorly regenerative cultivar. Inhibition of ethylene biosynthesis by CoCl2, at concentrations of 20 K, provoked a substantial enhancement of shoot regeneration (30 %): the control was poorly regenerative. However, CoCl2 had no effect when Ethephon was supplied. Inhibition of ethylene action by AgNO3, at concentrations of 10–25 M, caused a significant increase in plant regeneration: 25 % instead of 1.2 % in the control. Furthermore, addition of Ethephon to AgNO3-treated tissues failed to reduce the stimulation of shoot regeneration caused by AgNO3. On the basis of these findings, it is suggested that ethylene inhibits the regeneration process from cotyledons of sunflower.Abbreviations NAA
1-naphthalene acetic acid
- BAP
6-benzylamino-purine
- GA3
gibberellic acid
- Ethephon
2-chloroethylphosphonic acid
- MS
Murashige and Skoog medium
- AVG
aminoethoxyvinylglycine 相似文献
67.
Khalid Mohammed Khan Momin Khan Muhammad Ali Muhammad Taha Saima Rasheed Shahnaz Perveen M. Iqbal Choudhary 《Bioorganic & medicinal chemistry》2009,17(22):7795-7801
Bis-Schiff bases 1–27 have been synthesized and their in vitro antiglycation potential has been evaluated. Compounds 21 (IC50 = 243.95 ± 4.59 μM), 20 (IC50 = 257.61 ± 5.63 μM), and 7 (IC50 = 291.14 ± 2.53 μM) showed an excellent antiglycation activity better than the standard (rutin, IC50 = 294.46 ± 1.50 μM). This study has identified a series of potential molecules as antiglycation agents. A structure–activity relationship has been studied, and all the compounds were characterized by spectroscopic techniques. 相似文献
68.
69.
Biosurfactant production by Pseudomonas aeruginosa EBN-8 mutant was studied in shake flasks on separate wastes from canola, soybean and corn oil refineries. Of the substrates
tested, canola oil refinery waste (COD=20 g l−1) supplemented with sodium nitrate (at COD/N=20) showed the best microbial growth (4.50 g l−1) and rhamnolipid production (8.50 g l−1), at 10 d of incubation with the specific growth rate of 0.316 h−1 and specific product yield of 0.597 g g−1 h. Its cell-free supernatant showed the critical micelle dilution (CMD) of 150 and surface tension (ST) of 28.5 mN m−1. 相似文献
70.
Alonso Adel C Mederlyova A Novak M Grundke-Iqbal I Iqbal K 《The Journal of biological chemistry》2004,279(33):34873-34881
Mutations in the tau gene are known to cosegregate with the disease in frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17). However, the molecular mechanism by which these mutations might lead to the disease is not understood. Here, we show that four of the FTDP-17 tau mutations, R406W, V337M, G272V, and P301L, result in tau proteins that are more favorable substrates for phosphorylation by brain protein kinases than the wild-type, largest four-repeat protein tau4L and tau4L more than tau3L. In general, at all the sites studied, mutant tau proteins were phosphorylated faster and to a higher extent than tau4L and tau4L > tau3L. The most dramatic difference found was in the rate and level of phosphorylation of tau4L(R406W) at positions Ser-396, Ser-400, Thr-403, and Ser-404. Phosphorylation of this mutant tau was 12 times faster and 400% greater at Ser-396 and less than 30% at Ser-400, Thr-403, and Ser-404 than phosphorylation of tau4L. The mutated tau proteins polymerized into filaments when 4-6 mol of phosphate per mol of tau were incorporated, whereas wild-type tau required approximately 10 mol of phosphate per mol of protein to self-assemble. Mutated and wild-type tau proteins were able to sequester normal tau upon incorporation of approximately 4 mol of phosphate per mol of protein, which was achieved at as early as 30 min of phosphorylation in the case of mutant tau proteins. These findings taken together suggest that the mutations in tau might cause neurodegeneration by making the protein a more favorable substrate for hyperphosphorylation. 相似文献