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排序方式: 共有517条查询结果,搜索用时 31 毫秒
71.
Raina V Suar M Singh A Prakash O Dadhwal M Gupta SK Dogra C Lawlor K Lal S van der Meer JR Holliger C Lal R 《Biodegradation》2008,19(1):27-40
Soil pollution with hexachlorocyclohexane (HCH) has caused serious environmental problems. Here we describe the targeted degradation
of all HCH isomers by applying the aerobic bacterium Sphingobium indicum B90A. In particular, we examined possibilities for large-scale cultivation of strain B90A, tested immobilization, storage
and inoculation procedures, and determined the survival and HCH-degradation activity of inoculated cells in soil. Optimal
growth of strain B90A was achieved in glucose-containing mineral medium and up to 65% culturability could be maintained after
60 days storage at 30°C by mixing cells with sterile dry corncob powder. B90A biomass produced in water supplemented with
sugarcane molasses and immobilized on corncob powder retained 15–20% culturability after 30 days storage at 30°C, whereas
full culturability was maintained when cells were stored frozen at −20°C. On the contrary, cells stored on corncob degraded
γ-HCH faster than those that had been stored frozen, with between 15 and 85% of γ-HCH disappearance in microcosms within 20 h
at 30°C. Soil microcosm tests at 25°C confirmed complete mineralization of [14C]-γ-HCH by corncob-immobilized strain B90A. Experiments conducted in small pits and at an HCH-contaminated agricultural site
resulted in between 85 and 95% HCH degradation by strain B90A applied via corncob, depending on the type of HCH isomer and
even at residual HCH concentrations. Up to 20% of the inoculated B90A cells survived under field conditions after 8 days and
could be traced among other soil microorganisms by a combination of natural antibiotic resistance properties, unique pigmentation
and PCR amplification of the linA genes. Neither the addition of corncob nor of corncob immobilized B90A did measurably change the microbial community structure
as determined by T-RFLP analysis. Overall, these results indicate that on-site aerobic bioremediation of HCH exploiting the
biodegradation activity of S. indicum B90A cells stored on corncob powder is a promising technology. 相似文献
72.
Hannu Kankaanranta Aarne Lahdensuo Eeva Moilanen Peter J Barnes 《Respiratory research》2004,5(1):1-25
Many patients with persistent asthma can be controlled with inhaled corticosteroids (ICS). However, a considerable proportion of patients remain symptomatic, despite the use of ICS. We present systematically evidence that supports the different treatment options. A literature search was made of Medline/PubMed to identify randomised and blinded trials. To demonstrate the benefit that can be obtained by increasing the dose of ICS, dose-response studies with at least three different ICS doses were identified. To demonstrate whether more benefit can be obtained by adding long-acting β2-agonist (LABA), leukotriene antagonist (LTRA) or theophylline than by increasing the dose of ICS, studies comparing these options were identified. Thirdly, studies comparing the different "add-on" options were identified. The addition of a LABA is more effective than increasing the dose of ICS in improving asthma control. By increasing the dose of ICS, clinical improvement is likely to be of small magnitude. Addition of a LTRA or theophylline to the treatment regimen appears to be equivalent to doubling the dose of ICS. Addition of a LABA seems to be superior to an LTRA in improving lung function. However, addition of LABA and LTRA may be equal with respect to asthma exacerbations. However, more and longer studies are needed to better clarify the role of LTRAs and theophylline as add-on therapies. 相似文献
73.
BACKGROUND: Prolymphocytes are nucleolated cells that are the defining features of the 2 chronic lymphoproliferative disorders, prolymphocytic leukemia (PLL) and chronic lymphocytic leukemia (CLL) with increased prolymphocytes. Prolymphocytes appear relatively unfamiliar in cytopathology practice, and, particularly when present in body fluids, may resemble blasts or adult T-cell leukemia/ lymphoma (ATLL) cells. CASE: A 32-year-old man, referred to us with a diagnosis of acute leukemia, presented with shortness of breath for 2 months and loss of appetite for 3 months. He had enlarged liver and spleen, 6 and 8 cm, respectively, below the costal margin and pleural effusion. The raised total leukocyte count chiefly comprised prolymphocytes that, especially in the pleural fluid, had prominent nucleoli and significant pleomorphism, raising the possibility of blasts or ATLL. CONCLUSION: Prolymphocytes in body fluids can be misinterpreted as blasts or even ATLL cells. Better awareness among cytopathologists about prolymphocytes and the disease states in which they occur, as well as insistence, in a clinical setting of leukemia, on interpreting the pleural fluid in relation to the clinical and laboratory findings, especially those of the peripheral blood and bone marrow, can prevent misdiagnosis. Equally importantly, immunophenotyping must be done in such situations. 相似文献
74.
Seed Coat Microsculpturing in Brassica and Allied Genera (Subtribes Brassicinae, Raphaninae, Moricandiinae) 总被引:4,自引:0,他引:4
To obtain new information on the taxonomy of Brassica and alliedgenera, seed surfaces of 44 species (78 accessions) belongingto 11 genera of subtribes Brassicinae, Raphaninae and Moricandiinaewere examined using a scanning electron microscope. Ten typesof basic ornamentation patterns were recognized. While fourtypes were represented by only one species each, six types hadmore than one species either representing one genus (two types)or more (four types). The different species in each of the sixtypes could generally be distinguished from each other on thebasis of differences in microsculpturing features. This analysisprovides evidence for the close relationship among the variousgenera within the subtribe Brassicinae, and also the closenessof Raphanus, Enarthrocarpus and Moricandia of subtribe Raphaninaeand Moricandiinae, respectively, with the Brassicinae. Copyright2000 Annals of Botany Company Brassicinae, Moricandiinae, Raphaninae, SEM, seed coat microsculpturing, taxonomic implications 相似文献
75.
76.
Medha Raina Adil Moghal Amanda Kano Mathew Jerums Paul D. Schnier Shun Luo Rohini Deshpande Pavel V. Bondarenko Henry Lin Michael Ibba 《The Journal of biological chemistry》2014,289(25):17780-17790
Quality control operates at different steps in translation to limit errors to approximately one mistranslated codon per 10,000 codons during mRNA-directed protein synthesis. Recent studies have suggested that error rates may actually vary considerably during translation under different growth conditions. Here we examined the misincorporation of Phe at Tyr codons during synthesis of a recombinant antibody produced in tyrosine-limited Chinese hamster ovary (CHO) cells. Tyr to Phe replacements were previously found to occur throughout the antibody at a rate of up to 0.7% irrespective of the identity or context of the Tyr codon translated. Despite this comparatively high mistranslation rate, no significant change in cellular viability was observed. Monitoring of Phe and Tyr levels revealed that changes in error rates correlated with changes in amino acid pools, suggesting that mischarging of tRNATyr with noncognate Phe by tyrosyl-tRNA synthetase was responsible for mistranslation. Steady-state kinetic analyses of CHO cytoplasmic tyrosyl-tRNA synthetase revealed a 25-fold lower specificity for Tyr over Phe as compared with previously characterized bacterial enzymes, consistent with the observed increase in translation error rates during tyrosine limitation. Functional comparisons of mammalian and bacterial tyrosyl-tRNA synthetase revealed key differences at residues responsible for amino acid recognition, highlighting differences in evolutionary constraints for translation quality control. 相似文献
77.
78.
Khushboo Kritika Bhardwaj Preeti Singh Meenakshi Raina Vinay Sharma Deepak Kumar 《In vitro cellular & developmental biology. Plant》2018,54(5):495-507
Plants use various mechanisms to cope with drought constraints at morphological, physiological, and biochemical level by means of different adaptive mechanisms. All organisms use a network of signal transduction pathways to control their metabolism and to adapt to the environment. Among these pathways, calcium (Ca2+) ions play an important role as a universal second messenger. Calcium has unique properties and universal ability to transmit diverse signals that trigger primary physiological actions in the cell in response to hormones, pathogens, and stress factors. Calcium plays a fundamental role in regulating the polar growth of cells and tissues and participates in plant adaptation to various stress factors. This study was conducted to examine the role of Ca2+ in ameliorating the adverse effect of drought stress responses in two contrasting wheat genotypes, HD 2733 (drought sensitive) and HD 2987 (drought tolerant), differing in their drought tolerance. The plants were treated with mannitol or Hoagland solution and then supplemented with CaCl2 (10 mM). Measurements of seed germination, shoot growth, and chlorophyll content showed that calcium treatment increased all these factors in tolerant genotype (HD 2987) under induced stress condition. Drought stress reduced relative water content, osmolyte, and soluble sugar accumulation in both the genotypes, but CaCl2 supplementation increased all the components under stress condition in HD 2987 as compared to HD 2733. The oxidative damage caused by induced stress was lower in HD 2987 compared to HD 2733 genotypes as assessed by their higher photosynthetic capacity and lower electrolyte leakage, malondialdehyde (MDA) content as well as H2O2 accumulation. Less accumulation of superoxide and H2O2 was also observed in HD 2987 genotype after CaCl2 supplementation combined with mannitol treatment. In addition, the enhanced accumulation of calcium in the HD 2987 genotype is correlated with the higher activities of antioxidant enzymes than HD 2733 genotype under similar stress conditions. Our findings provide evidence of the protective role of exogenous calcium in conferring better tolerance against mannitol-induced drought stress in wheat genotypes, which could be useful as genetic stock to develop wheat tolerant varieties in breeding programs. 相似文献
79.
Gerardo Martin Carlos Yanez-Arenas Carla Chen Raina K. Plowright Rebecca J. Webb Lee F. Skerratt 《EcoHealth》2018,15(3):509-525
Disease risk mapping is important for predicting and mitigating impacts of bat-borne viruses, including Hendra virus (Paramyxoviridae:Henipavirus), that can spillover to domestic animals and thence to humans. We produced two models to estimate areas at potential risk of HeV spillover explained by the climatic suitability for its flying fox reservoir hosts, Pteropus alecto and P. conspicillatus. We included additional climatic variables that might affect spillover risk through other biological processes (such as bat or horse behaviour, plant phenology and bat foraging habitat). Models were fit with a Poisson point process model and a log-Gaussian Cox process. In response to climate change, risk expanded southwards due to an expansion of P. alecto suitable habitat, which increased the number of horses at risk by 175–260% (110,000–165,000). In the northern limits of the current distribution, spillover risk was highly uncertain because of model extrapolation to novel climatic conditions. The extent of areas at risk of spillover from P. conspicillatus was predicted shrink. Due to a likely expansion of P. alecto into these areas, it could replace P. conspicillatus as the main HeV reservoir. We recommend: (1) HeV monitoring in bats, (2) enhancing HeV prevention in horses in areas predicted to be at risk, (3) investigate and develop mitigation strategies for areas that could experience reservoir host replacements. 相似文献
80.
M B Blackburn H Jaffe J Kochansky A K Raina 《Archives of insect biochemistry and physiology》2001,48(3):121-128
Four new myoinhibitory peptides were isolated and identified from the ventral nerve cord of adult Manduca sexta. The new peptides are related to two previously identified myoinhibitory peptides also isolated from adult M. sexta, Mas-MIP I and Mas-MIP II. The sequences of the new peptides are APEKWAAFHGSWamide (Mas-MIP III), GWNDMSSAWamide (Mas-MIP IV), GWQDMSSAWamide (Mas-MIP V), and AWSALHGAWamide (Mas-MIP VI). Mas-MIPs III-VI were found to inhibit spontaneous peristalsis of the adult M. sexta anterior hindgut (ileum) in vitro. 相似文献