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71.
72.
An efficient and reliable transformation system for a very important medicinal plant Papaver bracteatum was developed through optimization of several factors that affect the rate of effective A. rhizogenes-mediated transformation and growth rate of hairy root. Five bacterial strains, A4, ATCC15834, LBA9402, MSU440 and A13, and three explants types, hypocotyls, leaves and excised shoots were examined. The highest frequency of transformation was achieved using LBA9402 strain in the excised shoots. Several inoculation and co-cultivation media and different concentration of arginine were evaluated using LBA9402 strain and the excised shoots as explant. Interestingly, a drastic increase in the frequency of transformation (47.3 %) was observed when Murashige and Skoog medium containing 1 mM arginine and lacking NH4NO3 KH2PO4, KNO3 and CaCl2 was used. The effect of sucrose concentration and the ratio of NH4 +: NO3 ? on hairy root biomass was examined. Maximum biomass was obtained in 30 g/l sucrose and 20:10 mM ratio of NH4 + to NO3 ? on MS medium. Transgenic hairy root lines were confirmed by polymerase chain reaction (PCR) and Southern hybridization.  相似文献   
73.

Introduction

The cerebral resting state in schizophrenia is altered, as has been demonstrated separately by electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) resting state networks (RSNs). Previous simultaneous EEG/fMRI findings in healthy controls suggest that a consistent spatiotemporal coupling between neural oscillations (EEG frequency correlates) and RSN activity is necessary to organize cognitive processes optimally. We hypothesized that this coupling is disorganized in schizophrenia and related psychotic disorders, in particular regarding higher cognitive RSNs such as the default-mode (DMN) and left-working-memory network (LWMN).

Methods

Resting state was investigated in eleven patients with a schizophrenia spectrum disorder (n = 11) and matched healthy controls (n = 11) using simultaneous EEG/fMRI. The temporal association of each RSN to topographic spectral changes in the EEG was assessed by creating Covariance Maps. Group differences within, and group similarities across frequencies were estimated for the Covariance Maps.

Results

The coupling of EEG frequency bands to the DMN and the LWMN respectively, displayed significant similarities that were shifted towards lower EEG frequencies in patients compared to healthy controls.

Conclusions

By combining EEG and fMRI, each measuring different properties of the same pathophysiology, an aberrant relationship between EEG frequencies and altered RSNs was observed in patients. RSNs of patients were related to lower EEG frequencies, indicating functional alterations of the spatiotemporal coupling.

Significance

The finding of a deviant and shifted coupling between RSNs and related EEG frequencies in patients with a schizophrenia spectrum disorder is significant, as it might indicate how failures in the processing of internal and external stimuli, as commonly seen during this symptomatology (i.e. thought disorders, hallucinations), arise.  相似文献   
74.
Coumarins are a well-known group of natural products distributed in the plant kingdom especially in the family Apiaceae with various biological activities. Isoarnottinin 4'-glucoside is a simple glycosylated coumarin found previously in a few genera of Apiaceae, and its biological activities have not been previously described in details. In the present paper, the compound was isolated from Prangos uloptera (Apiaceae) leaves using HPLC techniques. Antimicrobial, phytotoxic and cytotoxic activities of the compound were evaluated by disk diffusion, lettuce assay and MTT method. Our results indicated that the compound has high antibacterial effect against Erwinia carotovora, a common plant pathogen with MIC value of 100 microg/mL. The compound also exhibited significant phytotoxic activity against lettuce and modest cytotoxic activity against HeLa cell line with IC50 of 0 .84 mg/mL. It could be concluded that isoamottinin 4'-glucoside may play phytoalexin or allelopathic role for plant and may be a candidate for an antibacterial agent or a bioherbicide.  相似文献   
75.
The effects of salt stress on growth parameters, free proline content, ion accumulation, lipid peroxidation, and several antioxidative enzymes activities were investigated in S. persica and S. europaea. The seedlings were grown for 2 months in half-strength Hoagland solution and treated with different concentrations of NaCl (0, 85, 170, 340, and 510 mM) for 21 days. The fresh and dry weights of both species increased significantly at 85 and 170 mM NaCl and decreased at higher concentrations. Salinity increased proline content in both the species as compared to that of control. Sodium (Na+) content in roots and shoots increased, whereas K+ and Pi content in both organs decreased. At all NaCl concentrations, the total amounts of Na+ and K+ were higher in shoots than in roots. Malondialdehyde (MDA) content declined at moderate NaCl concentrations (85 and 170 mM) and increased at higher levels. With increased salinity, superoxide dismutase (SOD), catalase (CAT), and guaiacol peroxidase (GPX) activities also increased gradually in both species. In addition, it seems that GPX, CAT, and SOD activities play an essential protective role in the scavenging reactive oxygen species (ROS) in both species. Native polyacrylamide gel electrophoresis (PAGE) indicated different isoform profiles between S. persica and S. europaea concerning antioxidant enzymes. These results showed that S. persica exhibits a better protection mechanism against oxidative damage and it is more salt-tolerant than S. europaea possibly by maintaining and/or increasing growth parameters, ion accumulation, and antioxidant enzyme activities.  相似文献   
76.
A variety of Hantzsch 1,4-dihydropyridines were oxidized to the corresponding pyridines in high yields in the presence of H(6)PMo(9)V(3)O(40), a Keggin type heteropolyacid, in refluxing acetic acid. The heteropolyacid was found to be reusable.  相似文献   
77.
Although remarkable results have been attained by adoptively transferring T cells expressing fully murine and/or humanized anti-CD19 chimeric antigen receptors (CARs) to treat B cell malignancies, evidence of human anti-mouse immune responses against CARs provides a rationale for the development of less immunogenic CARs. By developing a fully human CAR (huCAR), these human anti-mouse immune responses are likely eliminated. This, perhaps, not only increases the persistence of anti-CD19 CAR T cells—thereby reducing the risk of tumor relapse—but also facilitates administration of multiple, temporally separated doses of CAR T cells to the same recipient. To these ends, we have designed and constructed a second-generation fully human anti-CD19 CAR (or huCAR19) containing a fully human single-chain variable fragment (ScFv) fused with a CD8a hinge, a 4-1BB transmembrane domain and intracellular T cell signaling domains of 4-1BB and CD3z. T cells expressing this CAR specifically recognized and lysed CD19+ target cells produced cytokines and proliferated in vitro. Moreover, cell volume data revealed that our huCAR construct cannot induce antigen-independent tonic signaling in the absence of cognate antigen. Considering our results, our anti-CD19 huCAR may overcome issues of transgene immunogenicity that plague trials utilizing CARs containing mouse-derived ScFvs. These results suggest that this huCAR19 be safely and effectively applied for adaptive T cell immunotherapy in clinical practice.  相似文献   
78.
Diverse tree structures such as blood vessels, branches of a tree and river basins exist in nature. The constructal law states that the evolution of flow structures in nature has a tendency to facilitate flow. This study suggests a theoretical basis for evaluation of flow facilitation within vascular structure from the perspective of evolution. A novel evolution parameter (Ev) is proposed to quantify the flow capacity of vascular structures. Ev is defined as the ratio of the flow conductance of an evolving structure (configuration with imperfection) to the flow conductance of structure with least imperfection. Attaining higher Ev enables the structure to expedite flow circulation with less energy dissipation. For both Newtonian and non-Newtonian fluids, the evolution parameter was developed as a function of geometrical shape factors in laminar and turbulent fully developed flows. It was found that the non-Newtonian or Newtonian behavior of fluid as well as flow behavior such as laminar or turbulent behavior affects the evolution parameter. Using measured vascular morphometric data of various organs and species, the evolution parameter was calculated. The evolution parameter of the tree structures in biological systems was found to be in the range of 0.95 to 1. The conclusion is that various organs in various species have high capacity to facilitate flow within their respective vascular structures.  相似文献   
79.
Regulation of regional work is essential for efficient cardiac function. In patients with heart failure and electrical dysfunction such as left branch bundle block regional work is often depressed in the septum. Following cardiac resynchronisation therapy (CRT) this heterogeneous distribution of work can be rebalanced by altering the pattern of electrical activation. To investigate the changes in regional work in these patients and the mechanisms underpinning the improved function following CRT we have developed a personalised computational model. Simulations of electromechanical cardiac function in the model estimate the regional stress, strain and work pre- and post-CRT. These simulations predict that the increase in observed work performed by the septum following CRT is not due to an increase in the volume of myocardial tissue recruited during contraction but rather that the volume of recruited myocardium remains the same and the average peak work rate per unit volume increases. These increases in the peak average rate of work is is attributed to slower and more effective contraction in the septum, as opposed to a change in active tension. Model results predict that this improved septal work rate following CRT is a result of resistance to septal contraction provided by the LV free wall. This resistance results in septal shortening over a longer period which, in turn, allows the septum to contract while generating higher levels of active tension to produce a higher work rate.  相似文献   
80.
An acceptable strategy to incorporate canthaxanthin (CX) as a natural colorant into products is by means of oil-in-water emulsions. The used CX in this study was produced by bacterium Dietzia natronolimnaea HS-1 using a batch bioreactor system. A central composite rotatable design-response surface methodology (CCRD-RSM) consisting of three-factored factorial design with five levels was applied for analysis of the results to obtain the optimal formulation of emulsions. Three independent variables including fenugreek gum (FG, 0.2-0.5%, w/w), coconut oil (CO, 6-10%, w/w), and CO/CX ratio (10:1-50:1) were transformed to coded values and second-order polynomial models was developed to predict the responses (p<0.0001). The studied independent variables were the stability, viscosity and droplet size properties such as volume-weighted mean diameter (D(43)), specific surface area (S(v)) and polydispersity index (PDI) of emulsions. The 3-D response surface plot derived from the mathematical models was used to determine the optimal conditions. Main emulsion components under the optimum conditions ascertained presently by RSM: 50:1 CO/CX ratio, 0.49% (w/w) FG content and 6.28% (w/w) CO concentration. At this optimum point, stability, viscosity, D(43), S(v) and PDI were 90.6%, 0.0118Pas, 0.595μm, 12.03m(2)/ml and 1.380, respectively.  相似文献   
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