Activities of some enzymes associated with oxygen metablolism, lipid peroxidation and cell permeability in dehydrated Malus micromalus seedlings

Measurements were made on the relative water content, cell permeability, superoxide dismutase (SOD) activity, catalase (CAT) activity and malondialdehyde (MDA) content in Malus micromalus seedlingduring dehydration in vitro in whole seedling and during dehydration in culture of different PEG 6000 concentration. The results indicated that SOD and CAT activities increased during dehydration from 0 to 3 h and decreased after dehydration for 3 h; MDA content decreased before 3 h dehydration and the MDA content and cell permeability increased significantly after 3 h in various treatments of dehydration (in vitro and in whole seedling). SOD and CAT activities in 20 days seedlings were higher than those in 10 days seedlings whereas the MDA content and cell permeability in 20 days seedlings were lower than those in 10 days seedlings. In 20 days seedlings during dehydration in vitro, SOD and CAT  activities in leaves were higher than those in root and the latter was higher than those in stem. However, the MDA content and cell permeability in leaves were lower than those in root which in turn were lower than those in stem. Significant correlations and regressions exist among the changes observed in the SOD activity, CAT activity, MDA content, cell permeability and the relative water content

Effects of space flight factors on genetic diversity of Buchloe dactyloides seeds

The objective of this research was to investigate the effects of space flight factors on Buchloe dactyloides “Jingyin No.3” seeds. After the retrieval, basic turf characters of plants were tested. Among the 100 plants tested, 21 showed great change on phenotype characters, including leaf blade length and width, height, stem diameter, number of tillers, number and length of stolon, length of stolon inter node, leaf color and extent of leaf turning yellow. 33 primers were screened in inter-simple sequence repeats (ISSR) analysis to evaluate DNA variation between mutations and their ground controls. Results show that 15.6 reliable bands were generated by 7 primers, of which 12.9 (80.9%) were polymorphic. Based on the study, we can conclude that the space flight factors could induce inheritable mutagenic changes on B. dactyloides seeds, and do further research to demonstrate these changes in genetic material of the mutants.Key words: Genetic diversity, Buchloe dactyloides, spaceflight, inter-simple sequence repeats

Preventive effect of polydatin against thrombosis: and its mechanism

This study aimed to investigate the effect of polydatin against thrombosis and its possible mechanisms. The methods of injection of arachidonic acid into mouse tail vein electrically stimulated carotid thrombosis in rats, and the rats’ inferior vena ligation were used to evaluate the antithrombotic effects of polydatin. Platelet aggregation was tested by use of Born’s method, and platelet cytosolic calcium was determined by use of Fura-2/AM. Thromboxane B2 and 6-keto-prostaglandin F1α level was monitored by the immuno-assay, while Rosette assay and Born’s method were used to observe plateletneutrophil interactions. The results show that polydatin had evident antithrombotic effects in the multiple-thrombosis models; the mechanisms may be closely related to its anti-platelet aggregation, which results in decrease of platelet cytosolic calcium and plasma thromboxane B2, while increasing plasma 6-keto-prostaglandin F1α Level and suppressing of platelet-neutrophil interactions.Key words: Polydatin, thromboxane A2, prostacyclin, platelet, neutrophil, cytosolic calcium

The mechanism of the polarization dependence of the optical transmission in subwavelength metal hole arrays

We investigate the mechanism of extraordinary optical transmission in subwave-length metal hole arrays. Experimental results for the arrays consisting of square or rectangle holes are well explained about the dependence of transmission strength on the polarization direction of the incident light. This polarization dependence occurs in each single-hole. For a hole array, there is in addition an interplay between the adjacent holes which is caused by the transverse magnetic field of surface plasmon polariton on the metal film surfaces. Based on the detailed study of a single-hole and two-hole structures, a simple method to calculate the total tranmissivity of hole arrays is proposed.Comment: 34 pages, 7 figure

Usability Test of Exercise Games Designed for Rehabilitation of Elderly Patients After Hip Replacement Surgery: Pilot Study

BACKGROUND: Patients who receive rehabilitation after hip replacement surgery are shown to have increased muscle strength and better functional performance. However, traditional physiotherapy is often tedious and leads to poor adherence. Exercise games, provide ways for increasing the engagement of elderly patients and increase the uptake o

ACER eNews 01 January 2007

This paper presents a centralized control system that coordinates parallel operations of different distributed generation (DG) inverters within a microgrid. The control design for the DG inverters employs a new Model Predictive Control algorithm that allows faster computational time for large power systems by optimizing the steady-state and the transient control problems separately. An overall energy management system is also implemented for the microgrid to coordinate load sharing among different DG units during both grid-connected and islanded operations. The design concept of the proposed control system is evaluated through simulation studies under different test scenarios. The impact of the increased penetration of DG units on the distribution grid is also investigated using the proposed microgrid. The simulation results show that the operations of the DG units within the microgrid can be coordinated effectively under the proposed control system to ensure stable operation of the overall microgrid

GPU-based Iterative Cone Beam CT Reconstruction Using Tight Frame Regularization

X-ray imaging dose from serial cone-beam CT (CBCT) scans raises a clinical concern in most image guided radiation therapy procedures. It is the goal of this paper to develop a fast GPU-based algorithm to reconstruct high quality CBCT images from undersampled and noisy projection data so as to lower the imaging dose. For this purpose, we have developed an iterative tight frame (TF) based CBCT reconstruction algorithm. A condition that a real CBCT image has a sparse representation under a TF basis is imposed in the iteration process as regularization to the solution. To speed up the computation, a multi-grid method is employed. Our GPU implementation has achieved high computational efficiency and a CBCT image of resolution 512\times512\times70 can be reconstructed in ~5 min. We have tested our algorithm on a digital NCAT phantom and a physical Catphan phantom. It is found that our TF-based algorithm is able to reconstrct CBCT in the context of undersampling and low mAs levels. We have also quantitatively analyzed the reconstructed CBCT image quality in terms of modulation-transfer-function and contrast-to-noise ratio under various scanning conditions. The results confirm the high CBCT image quality obtained from our TF algorithm. Moreover, our algorithm has also been validated in a real clinical context using a head-and-neck patient case. Comparisons of the developed TF algorithm and the current state-of-the-art TV algorithm have also been made in various cases studied in terms of reconstructed image quality and computation efficiency.Comment: 24 pages, 8 figures, accepted by Phys. Med. Bio

Magneto-transport and electronic structures in MoSi2_2 bulks and thin films with different orientations

We report a comprehensive study of magneto-transport properties in MoSi$_2$ bulk and thin films. Textured MoSi$_2$ thin films of around 70 nm were deposited on silicon substrates with different orientations. Giant magnetoresistance of 1000% was observed in sintered bulk samples while MoSi$_2$ single crystals exhibit a magnetoresistance (MR) value of 800% at low temperatures. At the low temperatures, the MR of the textured thin films show weak anti-localization behaviour owing to the spin orbit coupling effects. Our first principle calculation show the presence of surface states in this material. The resistivity of all the MoSi$_2$ thin films is significantly low and nearly independent of the temperature, which is important for electronic devices