Growth and photosynthetic response of four Malaysian indigenous tree species under different light conditions.

Growth and photosynthetic response of four indigenous tree seedlings, i.e. Dyera costulata, Dipterocarpus baudii, Neobalanocarpus heimii and Gonystylus affinis were studied under different light conditions in a degraded secondary forest. Maximum photosynthesis (Amax) was measured at 2 and 12 months after planting. The ratio of variable to maximum fluorescence (Fv/Fm) was determined. Leaves measured at 2 and 12 months after planting were old leaves present on the seedlings and new leaves that had expanded after planting respectively. Seedling growth was measured over four years. Changes in the growth rate and Amax with canopy openness were categorised into two groups. The growth and Amax of the first group (D. costulata and D. baudii) were maximum at 30-40% canopy openness. This group may be suitable for planting under large canopy gaps. The second group (G. affinis and N. heimii) showed maximum growth and Amax at relatively low canopy openness (less than 20%). Leaves in the second group suffered chronic photoinhibition under large gap. These species were suitable to be planted under low light conditions

Leaf photosynthetic and growth responses on four tropical tree species to different light conditions in degraded tropical secondary forest, Peninsular Malaysia.

Leaf ecophysiological responses and height growth were studied in four indigenous tree seedlings planted under different size gaps in degraded tropical secondary forest. Dyera costulata, Dipterocarpus baudii, Neobalanocarpus heimii, and Pouteria sp. were selected for study species. The leaf photosynthetic rate at light saturation (Amax), light compensation point (Ic), leaf nitrogen content, and SPAD value were measured at two months after planting. The ratio of variable to the maximum fluorescence (Fv/Fm), which represents the maximal photochemical efficiency of photosystem II was also determined at two months after planting. All measurement leaves were old leaves, which had acclimated before the planting light condition. Canopy openness above the seedlings was estimated from a hemispherical photograph, ranged from 6 to 53%. The relationships between canopy openness and Amax among species were categorized into two groups. The first group (N. heimii and Pouteria), which had relatively high wood density and late successional status, showed that the maximum Amax appeared under relatively low canopy openness such as approximately 10%. Amax of the second group (D. costulata and Dip. baudii), which had relatively low wood density and high light demand, maximized from 20 to 40% of canopy openness. Seedling height growth of the first group was lower than the second group. The first group also showed lower Fv/Fm at high canopy openness than the second group. These responses indicated that the first group may be categorized to less tolerant species for strong light conditions during the early transplanted stage. Ic of D. costulata, N. heimii and Pouteria decreased with decreasing canopy openness. These species have high acclimation ability to shade conditions from the early transplanted stage, since these responses contribute to raise the photosynthetic efficiency under shade conditions

Kidney transplantation recovers the reduction level of serum sulfatide in ESRD patients via processes correlated to oxidative stress and platelet count

Sulfatide is a major component of glycosphingolipids in lipoproteins. Recently, we reported that a low serum level of sulfatide in hemodialysis patients might be related to the high incidence of cardiovascular diseases. However, the serum kinetics of sulfatide in kidney disease patients and the function of endogenous serum sulfatide are still unclear. To obtain novel knowledge concerning these issues, we investigated the serum kinetics of sulfatide in 5 adult kidney transplant recipients. We also analyzed the correlated factors influencing the serum sulfatide level, using multiple regression analysis. Kidney transplantation caused a dramatic increase of serum sulfatide without an alteration of its composition in all recipients in a time-dependent manner; however, the recovery speed was slower than that of the improvement of kidney function and the serum sulfatide reached a nearly normal level after 1 year. Multiple regression analysis showed that the significant correlated factor influencing the serum sulfatide level was log duration (time parameter) throughout the observation period, and the correlated factors detected in the stable phase were the decrease of serum concentration of malondialdehyde (an oxidative stress marker) as well as the elevation of platelet count. The current study results demonstrated the gradual but reliable recovery of the serum sulfatide level in kidney transplant recipients for the first time, suggesting a close correlation between serum sulfatide and kidney function. The recovery of serum sulfatide might derive from the attenuation of systemic oxidative stress. The normal level of serum sulfatide in kidney transplant recipients might affect platelet function, and contribute to the reduction of cardiovascular disease incidence.ArticleGLYCOCONJUGATE JOURNAL. 28(3-4):125-135 (2011)journal articl

Programmable spin-state switching in a mixed-valence spin-crossover iron grid

Photo-switchable systems, such as discrete spin-crossover complexes and bulk iron–cobalt Prussian blue analogues, exhibit, at a given temperature, a bistability between low- and high-spin states, allowing the storage of binary data. Grouping different bistable chromophores in a molecular framework was postulated to generate a complex that could be site-selectively excited to access multiple electronic states under identical conditions. Here we report the synthesis and the thermal and light-induced phase transitions of a tetranucleariron(II) grid-like complex and its two-electron oxidized equivalent. The heterovalent grid is thermally inactive but the spin states of its constituent metal ions are selectively switched using different laser stimuli, allowing the molecule to exist in three discrete phases. Site-selective photo-excitation, herein enabling one molecule to process ternary data, may have major ramifications in the development of future molecular memory storage technologies

Carboxylic acid functionalized spin-crossover iron(II) grids for tunable switching and hybrid electrode fabrication

Two carboxyl-substituted iron(II) grids, one protonated, [Fe4(HL)4](BF4)4·4MeCN·AcOEt (1), and the other deprotonated, [Fe4(L)4]·DMSO·EtOH (2), where H2L = 4-{4,5-bis[6-(3,5-dimethylpyrazol-1-yl)pyrid-2-yl]-1H-imidazol-2-yl}benzoic acid, were synthesized. Single-crystal X-ray structure analyses reveal that both complexes have a tetranuclear [2 × 2] grid structure. 1 formed one-dimensional chains through intermolecular hydrogen bonds between the carboxylic acid units of neighboring grids, while 2 formed two-dimensional layers stabilized by π–π-stacking interactions. 1 showed spin transition between the 3HS-1LS and 1.5HS-2.5LS states around 200 K, while 2 showed spin-crossover between the 4LS and 2LS-2HS states above 300 K. A modified indium–tin oxide (ITO) electrode was fabricated by soaking the ITO in a solution of 1. The resultant electrode showed reversible redox waves attributed to the original redox processes of iron(II)/iron(III)

Antimicrobial Ointments and Methicillin-Resistant Staphylococcus aureus USA300

We tested 259 methicillin-resistant Staphylococcus aureus isolates and 2 USA300 ATCC type strains for susceptibility to bacitracin and neomycin contained in over-the-counter antibacterial ointments. Resistance to both bacitracin and neomycin was found only in USA300. The use of over-the counter antimicrobial drugs may select for the USA300 clone

Programmable spin-state switching in a mixed-valence spin-crossover iron grid

Photo-switchable systems, such as discrete spin-crossover complexes and bulk iron–cobalt Prussian blue analogues, exhibit, at a given temperature, a bistability between low- and high-spin states, allowing the storage of binary data. Grouping different bistable chromophores in a molecular framework was postulated to generate a complex that could be site-selectively excited to access multiple electronic states under identical conditions. Here we report the synthesis and the thermal and light-induced phase transitions of a tetranuclear iron(II) grid-like complex and its two-electron oxidized equivalent. The heterovalent grid is thermally inactive but the spin states of its constituent metal ions are selectively switched using different laser stimuli, allowing the molecule to exist in three discrete phases. Site-selective photo-excitation, herein enabling one molecule to process ternary data, may have major ramifications in the development of future molecular memory storage technologies

Kidney transplantation recovers the reduction level of serum sulfatide in ESRD patients via processes correlated to oxidative stress and platelet count

Sulfatide is a major component of glycosphingolipids in lipoproteins. Recently, we reported that a low serum level of sulfatide in hemodialysis patients might be related to the high incidence of cardiovascular diseases. However, the serum kinetics of sulfatide in kidney disease patients and the function of endogenous serum sulfatide are still unclear. To obtain novel knowledge concerning these issues, we investigated the serum kinetics of sulfatide in 5 adult kidney transplant recipients. We also analyzed the correlated factors influencing the serum sulfatide level, using multiple regression analysis. Kidney transplantation caused a dramatic increase of serum sulfatide without an alteration of its composition in all recipients in a time-dependent manner; however, the recovery speed was slower than that of the improvement of kidney function and the serum sulfatide reached a nearly normal level after 1 year. Multiple regression analysis showed that the significant correlated factor influencing the serum sulfatide level was log duration (time parameter) throughout the observation period, and the correlated factors detected in the stable phase were the decrease of serum concentration of malondialdehyde (an oxidative stress marker) as well as the elevation of platelet count. The current study results demonstrated the gradual but reliable recovery of the serum sulfatide level in kidney transplant recipients for the first time, suggesting a close correlation between serum sulfatide and kidney function. The recovery of serum sulfatide might derive from the attenuation of systemic oxidative stress. The normal level of serum sulfatide in kidney transplant recipients might affect platelet function, and contribute to the reduction of cardiovascular disease incidence.ArticleGLYCOCONJUGATE JOURNAL. 28(3-4):125-135 (2011)journal articl