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The magnetic properties and structural phase transformations of Heusler alloys [Ni.sub.2+x][Mn.sub.1-x]Ga and [Ni.sub.2-x][Mn.sub.1+x/2][Ga.sub.1+x/2] were investigated. It was found that the martensitic transformation temperature increases and the Curie temperature decreases with decreasing Mn concentration in the [Ni.sub.2+x][Mn.sub.1-x]Ga system, but the magnetic properties decrease faster than those do in the [Ni.sub.2-x][Mn.sub.1+x/2][Ga.sub.1+x/2] system. It suggests that the influence of the conduction electron concentration and the distance between Mn atoms on the Curie temperature is stronger than the magnetic dilution effect. The martensitic transformation temperature shows a peak value at x = 0.06 in the [Ni.sub.2-x][Mn.sub.1+x/2][Ga.sub.1+x/2] system. A large stress-free magnetic-field-induced strain (MFIS) of 1.8% has been obtained at room temperature in a single crystal sample with the composition in the first system. Index Terms--Magnetic-field-induced strain, magnetic properties, phase transformation.

According to large daily temperature difference, strong solar radiation and significant change of air humidity in the alpine area of Tibet, a field experiment was conducted to analyze the oat's diurnal variation of the leaf water potential (ψL), transpiration rate (Tr) and net photosynthetic rate (Pn). Meanwhile, the relationship between oat's physiological indicators and typical meteorological factors (atmospheric temperature (T), solar radiation (Rs), relative air humidity (RH)) were investigated with regression models. Results showed that the oat's daily change curve of ψL showed 'V-type' in the seeding and heading stages and 'W-type' in the jointing and tillering stages. As shown in the results, oat's Pn presented a decreasing tendency in a day and the peak appearing between 9:00 and 10:00 at one day in each growing stage. The Tr presented double-peak curves and midday depression in the seeding and heading stages. The variation tendency about oat's Tr in the tillering stage and jointing stage was "Multipeak" type without distinct midday depression and parabolic tendency. By multiple regression analysis between the data of oat's physiological indexes and comprehensive factors, the ψL, Tr and Pn of oat in alpine region can be predicted under condition of adequate water supply. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Granulocyte colony-stimulating factor (G-CSF) plays a role in regulating phosphatidylinositol-3-kinase/serine/threonine kinase (PI3K/AKT) pathway, affecting cell proliferation and apoptosis, and inducing vascular endothelial growth factor (VEGF) expression. This study investigated the mechanism of G-CSF on angiogenesis and neural protection after intracerebral hemorrhage (ICH). MATERIALS AND METHODS: The rats were divided into four groups, including sham, ICH, ICH+G-CSF, and ICH+G-CSF+LY294002 (PI3K/AKT signaling pathway specific inhibitor). Cerebral neurological dysfunction was tested by Garcia scoring. Cell apoptosis was detected by transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) assay. Angiogenesis marker CD34 expression, PI3K/AKT signaling pathway, B-cell lymphoma-2 (Bcl-2), and VEGF expressions were compared by IHC. Rat cerebral nerve RN-c cells were divided into four groups, including control, oxygen-glucose deprivation (OGD), OGD+G-CSF, and OGD+G-CSF+LY294002. RESULTS: Neurological dysfunction was more evident; CD34+ cell number, VEGF expression, and cell apoptosis significantly increased; phosphorylated AKT (p-AKT) and Bcl-2 levels markedly reduced in ICH group compared with sham group. G-CSF apparently up-regulated p-AKT and Bcl-2 expressions, attenuated cell apoptosis, and elevated CD34+ cell number. LY294002 significantly decreased p-AKT, Bcl-2, and VEGF expressions, and alleviated the cell apoptosis protective and angiogenesis effect induced by G-CSF. OGD treatment induced RN-c cell apoptosis, down-regulated p-AKT and Bcl-2 expressions, and enhanced the tube capacity of vascular endothelial cells (VEC). G-CSF markedly elevated p-AKT and Bcl-2 contents in RN-c cells, declined cell apoptosis, increased p-AKT and VEGF levels in VEC, and enhanced tube capacity. CONCLUSIONS: G-CSF enhanced PI3K/AKT signaling pathway activity, promoted Bcl-2 and VEGF expression, reduced nerve cell apoptosis, and enhanced tube capacity of VECs, which may be the mechanism of G-CSF in improving neurological function and angiogenesis after ICH. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To study the structural and functional changes in mitochondria in astrocytes of the cerebral cortex of the rats in the simulated sepsis environment in vitro and the relationship between these changes and the biogenesis of mitochondria in astrocytes by establishing models of sepsis astrocytes. MATERIALS AND METHODS: The structural and functional changes in mitochondria in astrocytes of the cerebral cortex of the rats were evaluated. The ultra structural changes in the mitochondria, astrocytes, and ultrathin sections, were observed with a transmission electron microscope. The expression of the regulatory factors related to biogenesis of mitochondria in astrocytes of the cerebral cortex of the rats was evaluated in various experimental groups. RTPCR and Western blot were used to evaluate the expression of the regulatory factors related to biogenesis of mitochondria in astrocytes of the cerebral cortex of the rats. The "point grid method" was used to evaluate the volume density of the mitochondria in the astrocytes of the cerebral cortex of the rats in various experimental groups. The Western blotting was used to evaluate the role of fusion and fission of mitochondria in the astrocytes of the cerebral cortex of the rats in various experimental groups in regulating the expression of the protein-OPAI and DRPI. RESULTS: In the sepsis astrocyte models established by co-incubation of LPS and IFN-γ and astrocytes of the cerebral cortex of the rats, the mitochondria with a minor injury in the 6 h group (2.97± 0.92) increased significantly when compared with those in the 0 h group (1.08±0.95), 12 h group (1.70±1.01), and 24 h group (1.59±0.55) (p<0.05); the concentration of adenosine triphosphate (ATP) in the astrocytes of the cerebral cortex of the rats in the 6 h, 12 h, and 24 h groups increased significantly when compared with that in the 0 h group (p<0.05). PGC-1α mRNA, NRF-1 mRNA, NRF-2α mRNA, NRF-2β mRNA, and mitochondrial transcription factor A (TFAM) mRNA in the astrocytes of the cerebral cortex of the rats in the 6 h and 12 h groups increased significantly when compared with those in the 0 h group (p<0.05); the concentration of TFAM mRNA (1.20±0.19) increased significantly when compared with that in the 0 h group (p<0.05). The OPAI protein concentration (1.21±0.17:1.34±0.06) and DRPI protein concentration (1.04±0.05; 1.05±0.05) in the astrocytes of the cerebral cortex of the rats in the 12 h group (1.25±0.17), 24 h group (1.33±0.24), and 6 h group increased significantly when compared with that in the 0 h group (p <0.05). CONCLUSIONS: The experimental sepsis conditions can cause a minor injury of the ultrastructure of the mitochondria in the astrocytes of the cerebral cortex of the rats. The biogenesis of the mitochondria in the astrocytes of the cerebral cortex of the rats was strengthened to cater for the increased demand for energy of the astrocytes under the sepsis conditions and finally recover the ultrastructure of the mitochondria with a minor injury. In response to the increased mitochondrial biogenesis, the activities of the mitochondrial fusion and fission of the astrocytes of the cerebral cortex of the rats were increased. [ABSTRACT FROM AUTHOR]

The effect of Cux substituted for Gax on the thermodynamic characteristic, evolution of phases and fracture behavior in Ni50Mn30Ga20 − xCux alloys have been investigated. The results show that the martensitic transformation, reverse transformation temperatures and average interface temperature of Ni50Mn30Ga20 − xCux sample increase remarkably with increased content of Cu. The hysteresis temperature of the austenite to martensite transition firstly showed a steep rising trend, then almost reduced to a lower rate with the increased content of Cu up to 4 at.% (the maximum level of copper addition studied). The (202) diffraction peak position was observed to shifted towards high angles, when the Cu content was lower than 1 at.%. Further, the, M202 diffraction peak was found to split into two diffraction peaks when the Cu content was more than 1 at.%. In addition, the compressive strength and fracture strain of alloys is clearly enhanced with increased content of Cu. Furthermore, the fracture type of Ni50Mn30Ga20 − xCux alloys was found to changes from intergranular fracture for the Ni–Mn–Ga alloys, to transgranular cleavage fracture with increase in Cu content. [ABSTRACT FROM AUTHOR]