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排序方式: 共有320条查询结果,搜索用时 312 毫秒
41.
This article presents an overview of the mechanism of chromium (Cr) stress in plants. Toxic effects of Cr on plant growth and development depend primarily on its valence state. Cr(VI) is highly toxic and mobile whereas Cr(III) is less toxic. Cr-induced oxidative stress involves induction of lipid peroxidation in plants that cause severe damage to cell membranes which includes degradation of photosynthetic pigments causing deterioration in growth. The potential of plants with the adequacy to accumulate or to stabilize Cr compounds for bioremediation of Cr contamination has gained engrossment in recent years. 相似文献
42.
Shamsul Hayat Mohd Irfan Arif Wani Alyemeni Nasser Aqil Ahmad 《Plant signaling & behavior》2012,7(1):93-102
Salicylic acid is well known phytohormone, emerging recently as a new paradigm of an array of manifestations of growth regulators. The area unleashed yet encompassed the applied agriculture sector to find the roles to strengthen the crops against plethora of abiotic and biotic stresses. The skipped part of integrated picture, however, was the evolutionary insight of salicylic acid to either allow or discard the microbial invasion depending upon various internal factors of two interactants under the prevailing external conditions. The metabolic status that allows the host invasion either as pathogenesis or symbiosis with possible intermediary stages in close systems has been tried to underpin here. 相似文献
43.
Richard L. Williams Sok Bee Lim Hayat Onyuksel Phillip T. Marucha 《International journal of peptide research and therapeutics》2012,18(3):195-203
KSLW is an antimicrobial decapeptide, presumed to associate with micelles. Linear polymeric chains of hydrophobic phospholipids tend to form micelles, spontaneously, and function as efficient drug-stabilizing delivery systems. Our goal was to examine whether association of a cationic decapeptide with sterically stabilized nanomicelles (SSMs), improves stability and antimicrobial effect in vivo, using an impaired healing model. KSLW solutions were prepared in either saline or 12?mM SSM. Bilateral circular excisional wounds were created on the backs of SKH-1 mice followed by intradermal delivery of peptide solutions. Bacterial assays were conducted to assess bioactivity of KSLW in different formulations. Fluorescence analyses demonstrated an optimum lipid:peptide ratio for loading KSLW in PEGylated phospholipid micelles to be 15:1. Stressed animals treated with KSLW?CSSM preparations demonstrated no differences in microbial load at post-operative time points. In vitro assays against Staphylococcus epidermidis confirmed diminished activity of KSLW in SSM solution. The loss of KSLW antimicrobial activity may be based on electrostatic interactions with the anionic surface of SSM, which interfere with the peptide??s interaction with bacterial membranes. This study emphasizes the importance of antimicrobial peptide charge, size, and bioactivity, when designing delivery systems for wound healing agents. 相似文献
44.
Arujuna A Murphy C Hayat A Seffens H Gill JS 《Indian pacing and electrophysiology journal》2012,12(3):82-92
IntroductionWe describe the use of a ablating system to compartmentalise and regionally isolate the atria in paroxysmal and persistent atrial fibrillation (AF).Methods40 patients were studied, 25 paroxysmal AF and 14 persistent AF. One patient enrolled was later found to be in left atrial flutter and was excluded. The Cardima Revelation® TX catheter system with Intellitemp® Radiofrequency (RF) energy control device and a Medtronic Atakar® RF generator were used to place wide area circumferential ablations to achieve conduction block into the left and right sided pulmonary veins. Roof lines and mitral isthmus lines were also performed. In patients with persistent AF and in repeat procedures, right atrial compartmentalisation was performed with an anterior superior vena cava (SVC) to inferior vena cava (IVC) line and a septal SVC to IVC line.ResultsAt 6 months, 18 of the 39 patients were asymptomatic, 10 had improved symptoms and 22 were in sinus rhythm. In the paroxysmal group, 11 were asymptomatic, 7 had improved symptoms and 16 (64%) were in sinus rhythm. In the persistent group, 7 were asymptomatic, 3 had improved symptoms and 6 (43%) were in sinus rhythm. The total group AF burden was 37.8 ± 5.4 hrs pre-procedure and 23.1 ± 5.1 hrs at 6 months post procedure. Mean temperature, impedance and power recorded at each pole demonstrated effective power delivery at all poles. No catheter charring was observed, complication rates were comparable to standard AF ablation technique.ConclusionLinear ablation in the left and right atria to mimic Cox’s Maze is feasible and safe using this ablating system. 相似文献
45.
Descamps S Arzouk H Bacou F Bernardi H Fedon Y Gay S Reyne Y Rossano B Levin J 《Cell and tissue research》2008,332(2):299-306
Secreted Frizzled-related proteins (Sfrps) are extracellular regulators of Wnt signalling and play important roles in developmental
and oncogenic processes. They are known to be upregulated in regenerating muscle and in myoblast cultures but their function
is unknown. Here, we show that the addition of recombinant Sfrp1 or Sfrp2 to C2C12 cell line cultures or to primary cultures
of satellite cells results in the inhibition of myotube formation with no significant effect on the cell cycle or apoptosis.
Even though at confluence, treated and untreated cultures are identical in appearance, analyses have shown that, for maximum
effect, the cells have to be treated while they are proliferating. Furthermore, removal of Sfrp from the culture medium during
differentiation restores normal myotube formation. We conclude that Sfrp1 and Sfrp2 act to prevent myoblasts from entering
the terminal differentiation process.
S. Descamps and J. Levin contributed equally to this work. 相似文献
46.
Thirty-day-old plants of mustard (Brassica juncea L.) were sprayed with 10−10, 10−8, or 10−6 M aqueous solution of 28-homobrassinolide (HBR). The HBR-treated plants were healthier than those treated with water and
yielded more. Maximum increase over control was found in 60-d-old, 10−8 M-HBR-treated plants in fresh and dry mass per plant, carbonic anhydrase (CA, E.C. 4.2.1.1) activity, and net photosynthetic
rate (P
N), at harvest in number of pods per plant and seed yield per plant (the respective values were 25, 30, 34, 69, 24, and 29
%). A further increase in the concentration of HBR (10−6 M) did not make any additional impact on the growth and yield. Increased CA activity and P
N were correlated with growth and seed yield.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
47.
Despite great advances in the field of vaccination, there are still needs for novel and effective vaccines because still no effective vaccines have been produced for some diseases such as malaria, acquired immune deficiency syndrome (AIDS), and tuberculosis. Furthermore, many of the existing vaccines have disadvantages such as failure to stimulate completely the immune system, in vivo instability, high toxicity, the need for cold chain, and multiple administrations. Nanotechnology has been raised as a powerful tool for solving these problems in this regard. Generally, nanovaccines are a new generation of vaccines using nanoparticles (NPs) as carriers and/or adjuvants. Due to the similar scale (size) between the NPs and pathogens, the immune system can be stimulated well, resulting in triggered cellular and humoral immunity responses. Other benefits of the nanovaccines include their better stability in blood flow to increase the shelf life in blood, enhanced immune system stimulation, no need for booster doses, no need to maintain the cold chain, and ability to create active targeting. In addition, nanovaccines have raised the hope to treat diseases such as rheumatoid arthritis, AIDS, malaria, and chronic autoimmune, and so forth. 相似文献
48.
This study examines the simultaneous effects of heat and mass transfer on the three-dimensional boundary layer flow of viscous fluid between two infinite parallel plates. Magnetohydrodynamic (MHD) and thermal radiation effects are present. The governing problems are first modeled and then solved by homotopy analysis method (HAM). Influence of several embedded parameters on the velocity, concentration and temperature fields are described. 相似文献
49.
Steven W. Kortum Rhonda M. Lachance Barbara A. Schweitzer Gopichand Yalamanchili Hayat Rahman Michael D. Ennis Rita M. Huff Ruth E. TenBrink 《Bioorganic & medicinal chemistry letters》2009,19(20):5919-5923
Herein we describe the design and synthesis of a novel series of potent thienopyrimidine P2Y12 inhibitors and the negative impact protein binding has on the inhibition of platelet aggregation. 相似文献
50.
Hayat Badshah Farman Ullah Paul Andre Calatayud 《Biocontrol Science and Technology》2016,26(12):1605-1616
In Pakistan, the cotton mealybug, Phenacoccus solenopsis Tinsley (Sternorrhyncha (Homoptera): Pseudococcidae), is a serious pest of many cultivated plants. A parasitoid, Aenasius bambawalei Hayat (Hymenoptera: Encyrtidae), is associated with P. solenopsis. In order to mass rear A. bambawalei for a biological control programme, it is important to investigate the parasitoid’s host stage preference and its parasitism behaviour for P. solenopsis in order to optimise production. The present study showed that under both choice and no-choice conditions, the parasitoid preferred third instar and pre-reproductive host stage mealybugs for parasitism. Parasitoid larva developing inside the host exhibited a greater longevity, shorter developmental period and longer body size in these preferred host stages. Our study also confirmed that A. bambawalei showed no attraction to male mealybugs and no host feeding on any host stage was recorded. The ability of the parasitoid to effectively discriminate between suitable and non-suitable stages means that it is feasible to rear it on a mixed population. 相似文献