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排序方式: 共有383条查询结果,搜索用时 15 毫秒
41.
Nadeem Hashmi M. Masroor A. Khan Moinuddin Mohd Idrees Tariq Aftab 《Plant Growth Regulation》2012,68(2):281-291
Fennel (Foeniculum vulgare Mill) is a high-value medicinal and essential oil bearing plant used extensively in pharmaceutical, food and cosmetic industries. A pot experiment was carried out in the natural conditions of net house to resolve whether the foliar application of salicylic acid (SA) might enhance the growth, yield and essential oil production of fennel. Plants were sprayed three times with SA. The first spray was carried out at 40?days after sowing (DAS); the second and third sprays were applied one and 2?weeks later, the plants were sprayed with deionised water (control) and different concentrations of SA (10?5, 10?4 and 10?3?M). The foliar spray of SA at 10?4?M significantly enhanced the vegetative growth (shoot and root lengths, fresh and dry weights), physiological and biochemical characteristics (chl ??a??, chl ??b??, total chlorophyll and carotenoids contents, nitrate reductase activity, carbonic anhydrase activity, leaf-N, -P and -K contents), yield characteristics (number of umbels and fruits, 1,000-seed weight and seed yield) and essential oil yield of fennel. GLC analysis revealed the significant increase in the components of essential oil, viz. trans-anethole (80.4?C84.7?%), methyl chavicol (2.3?C2.5?%) and fenchone (5.6?C7.9?%). It was concluded that foliar spray of SA at 10?4?M might be employed for enhancing the plant growth as well as yield and quality of essential oil of fennel. 相似文献
42.
M. Naeem Mohd. IdreesTariq Aftab M. Masroor A. KhanMoinuddin Lalit Varshney 《Carbohydrate polymers》2012,87(2):1211-1218
Irradiated carrageenan (IC) could elicit plant growth promoting activities in plants. The effect of foliar spray of five concentrations of IC (20, 40, 60, 80 and 100 mg L−1) was studied on Mentha arvensis L. in terms of plant growth, physiological attributes, herbage yield and the content and yield of essential oil and its components. Un-irradiated carrageenan and deionized water had no effect on the attributes studied. GPC study revealed formation of low molecular weight fractions in irradiated samples containing less than 20,000 molecular weight oligomers which are responsible for plant growth promotion in this study. 80 mg L−1 of IC was the most effective concentration which resulted in the highest values of growth attributes, herbage yield and the content and yield of essential oil and menthol content of the oil. It also improved the leaf-nutrient contents, photosynthetic rate and other physiological parameters. 100 mg L−1 of IC did not further improve the attributes studied, but it was always better than the control. 相似文献
43.
MH Kim AL Tsuhako EW Co DT Aftab F Bentzien J Chen W Cheng S Engst L Goon RR Klein DT Le M Mac JJ Parks F Qian M Rodriquez TJ Stout JH Till KA Won X Wu FM Yakes P Yu W Zhang Y Zhao P Lamb JM Nuss W Xu 《Bioorganic & medicinal chemistry letters》2012,22(15):4979-4985
Variously substituted indolin-2-ones were synthesized and evaluated for activity against KDR, Flt-1, FGFR-1 and PDGFR. Extension at the 5-position of the oxindole ring with ethyl piperidine (compound 7i) proved to be the most beneficial for attaining both biochemical and cellular potencies. Further optimization of 7i to balance biochemical and cellular potencies with favorable ADME/ PK properties led to the identification of 8h, a compound with a clean CYP profile, acceptable pharmacokinetic and toxicity profiles, and robust efficacy in multiple xenograft tumor models. 相似文献
44.
The menisci are important fibrocartilaginous structures which give lubrication, shock absorption, nutrition and stabilisation to the knee joint, and also help transfer load. The meniscus' extracellular matrix possesses a complex architecture which is not uniform throughout the tissue. The inner third of the meniscus is composed of hyaline cartilage and the outer meniscus is composed of fibrocartilage. In a mature meniscus only the outer 10-25% is vascularised. There are various types of pathology associated with the meniscus. Previously, surgical techniques used to be considered as conventional treatment for meniscal lesions. However lesions in the avascular regions of the meniscus would rarely heal appropriately. It has been found that total menisectomies in patients may increase their chance of suffering from osteoarthritis in the future. Meniscal tissue engineering has been developed in an attempt to help improve the healing potential of avascular meniscal regions. Many different concepts and approaches have been tried and tested, such as the application of natural and synthetic scaffolds, mesenchymal stem cells, growth factors, fibrin glue and more. The objective of this review is to summarise the different approaches that have been used in the development of meniscal tissue engineering. The focus of this review is to evaluate the strengths and weaknesses of the studies that have been carried out, and from there determine what we have learnt from them in order to further the development in meniscal tissue engineering. 相似文献
45.
As our population demographics change, osteoarthritis and cartilage defects are becoming more prevalent. The discovery of stems cells and their ability for indefinite regeneration has revolutionised the way cartilage problems are viewed. Tissue engineering has been shown to be the ideal way of repairing articular cartilage lesions, i.e. back to native tissue. Cartilage is an ideal tissue engineering target as it is avascular, aneural and alymphatic. The two main types of stem cells being investigated in chondrogenesis are embryological and mesenchymal stem cells. Research into embryological stem cells has been surrounded by controversy because of ethical, religious and social concerns. We discuss the use of embryological and mesenchymal stem cells in cartilage repair and the various factors involved in the differentiation into chondrocytes. We also discuss commonly used mesenchymal stem cell markers and their limitations. 相似文献
46.
47.
Ahmad MF Singh D Taiyab A Ramakrishna T Raman B Rao ChM 《Journal of molecular biology》2008,382(3):812-824
Oxidative stress and Cu2+ have been implicated in several neurodegenerative diseases and in cataract. Oxidative stress, as well as Cu2+, is also known to induce the expression of the small heat shock proteins α-crystallins. However, the role of α-crystallins in oxidative stress and in Cu2+-mediated processes is not clearly understood. We demonstrate using fluorescence and isothermal titration calorimetry that α-crystallins (αA- and αB-crystallin and its phosphorylation mimic, 3DαB-crystallin) bind Cu2+ with close to picomolar range affinity. The presence of other tested divalent cations such as Zn2+, Mg2+, and Ca2+ does not affect Cu2+ binding, indicating selectivity of the Cu2+-binding site(s) in α-crystallins. Cu2+ binding induces structural changes and increase in the hydrodynamic radii of α-crystallins. Cu2+ binding increases the stability of α-crystallins towards guanidinium chloride-induced unfolding. Chaperone activity of αA-crystallin increases significantly upon Cu2+ binding. α-Crystallins rescue amyloid beta peptide, Aβ1-40, from Cu2+-induced aggregation in vitro. α-Crystallins inhibit Cu2+-induced oxidation of ascorbate and, hence, prevent the generation of reactive oxygen species. Interestingly, α-synuclein, a Cu2+-binding protein, does not inhibit this oxidation process significantly. We find that the Cu2+-sequestering (or redox-silencing) property of α-crystallins confers cytoprotection. To the best of our knowledge, this is the first study to reveal high affinity (close to picomolar) for Cu2+ binding and redox silencing of Cu2+ by any heat shock protein. Thus, our study ascribes a novel functional role to α-crystallins in Cu2+ homeostasis and helps in understanding their protective role in neurodegenerative diseases and cataract. 相似文献
48.
Azeem Z Jelani M Naz G Tariq M Wasif N Kamran-Ul-Hassan Naqvi S Ayub M Yasinzai M Amin-Ud-Din M Wali A Ali G Chishti MS Ahmad W 《Human genetics》2008,123(5):515-519
Autosomal recessive hypotrichosis (LAH3) is a rare hair disorder characterized by sparse hair on scalp and the rest of the
body of affected individuals. Recently mutations in a G protein-coupled receptor gene, P2RY5, located at LAH3 locus, have been reported in several families with autosomal recessive hypotrichosis simplex and woolly
hair. For the present study, 22 Pakistani families with autosomal recessive hypotrichosis were enrolled. Genotyping using
microsatellite markers linked to three autosomal recessive forms of hypotrichosis (LAH1, LAH2, LAH3) showed the linkage of
2 families to the LAH2 locus and 14 to the LAH3 locus. The remaining 6 families were not linked to any of the three loci.
Families linked to LAH3 locus were further subjected to screening of the P2RY5 gene with direct DNA sequencing. Three previously reported variants, c.69insCATG (p.24insHfs52), c.188A > T (p.D63V) and
c.565G > A (p.E189K) were observed in eight families. Four novel nonsynonymous sequence variants, c.8G > C (p.S3T), c.36insA
(p.D13RfsX16), c.160insA (p.N54TfsX58) and c.436G > A (p.G146R) were found to segregate within six families.
Z. Azeem, M. Jelani, G. Naz, M. Tariq, N. Wasif, S. Kamran-ul-Hassan Naqvi contributed equally to this work. 相似文献
49.
Aftab Ahamed Ajay Singh Owen P. Ward 《World journal of microbiology & biotechnology》2005,21(8-9):1577-1583
Summary While Aspergillus strains are also being considered as potential hosts for production of extracellular heterologous proteins, the proteases
produced by the host are highly problematic in that they typically modify and degrade the recombinant proteins. Culture-based
approaches for minimization of protease activity in culture supernatants of Aspergillus niger NRRL-3 included reduction or elimination of peptide nitrogen in the medium, preferential use of a defined salts medium rather
than a non-peptide nitrogen medium containing yeast-nitrogen base, supplementation of the medium with carboxymethylcellulose
and cultivation at pH 6.5 rather than 7.5. In general, increased proteolytic activity was observed after maximum biomass was
observed and biomass was declining suggesting the majority of protease activity was released by cell lysis. Carboxymethylcellulose
shifted mycelial morphology from pelleted to filamentous. Mycelium lysis in the centre of pellets, with resultant release
of intracellular proteases, would explain why filamentous cultures exhibited much lower proteolytic activity than pelleted
cultures. 相似文献
50.
Hassina Tabassum Chenxu Zhi Tanveer Hussain Tianjie Qiu Waseem Aftab Ruqiang Zou 《Liver Transplantation》2019,9(39)
Trogtalite CoSe2 nanobuds encapsulated into boron and nitrogen codoped graphene (BCN) nanotubes (CoSe2@BCN‐750) are synthesized via a concurrent thermal decomposition and selenization processes. The CoSe2@BCN‐750 nanotubes deliver an excellent storage capacity of 580 mA h g?1 at current density of 100 mA g?1 at 100th cycle, as the anode of a sodium ion battery. The CoSe2@BCN‐750 nanotubes exhibit a significant rate capability (100–2000 mA g?1 current density) and high stability (almost 98% storage retention after 4000 cycles at large current density of 8000 mA g?1). The reasons for these excellent storage properties are illuminated by theoretical calculations of the relevant models, and various possible Na+ ion storage sites are identified through first‐principles calculations. These results demonstrate that the insertion of heteroatoms, B–C, N–C as well as CoSe2, into BCN tubes, enables the observed excellent adsorption energy of Na+ ions in high energy storage devices, which supports the experimental results. 相似文献