AKTIVITAS ANTIOKSIDAN SEDIAAN NANOPARTIKEL KITOSAN EKSTRAK ETANOL KELOPAK ROSELA (Hibiscus sabdariffa L) PADA TIKUS HIPERKOLESTEROL : PENGUKURAN KADAR MALONDIALDEHID (MDA)

Hypercholesterolemia can induce oxidative stress and are associated with atherosclerosis and other cardiovascular disorders. Administration of a preparation of chitosan nanoparticles roselle extract (NKER) can prevent oxidative stress because it contains flavonoids which have an effect as an antioxidant anthocyanin. Decreased oxidative stress can be determined by measuring the levels of malondealdehid (MDA) produced by the reaction of lipid peroxidation. The purpose of this study was to determine the effect of administration of a preparation of chitosan nanoparticles roselle calyx ethanol extract of antioxidant activity by measuring the levels of MDA. This study used 25 adult rats of Sprague Dawley strain were divided into 5 groups. The first group was given a standard feed diet as baseline, group II was induced with pure cholesterol. Group III, IV and V induced pure cholesterol as well as the dosage given NKER with successive doses of 25 mg/kg, 50 mg/kg and 100 mg/KgBB. The treatment was done for 30 days. On day - 31 each rat blood taken for measurement of total cholesterol, as well as the measurement of MDA using thiobarbituric acid reactive substance (TBARS). The results showed an increase in levels of MDA in mice induced pure cholesterol (group II) with a mean concentration of 7.13 ± 0.22 nmol / ml significantly different to the baseline with a mean concentration of 0.87 ± 0.77 nmol / ml (p≤0,05). The mean levels of MDA in group III, IV and V respectively was 5.49 ± 0.18 nmol / ml; 4.18 ± 0.37 nmol / ml; and 2.18 ± 0.15 nmol / ml,significantly different when compared with the baseline group and the group II (p≤0,05). Decreased levels of MDA in mice given dosage NKER hypercholesterolemia showed that nker preparations have antioxidant activity, which is owned by the highest antioxidant activity NKER dosage dose 100mg/KgBB. Keywords : Antioxidant, Nanoparticles, Roselle, malondialdehyd

Learning in Hybrid-Project Systems: The Effects of Project Performance on Repeated Collaboration

This study advances contingency theories of performance-outcome learning in hybrid-project systems, in which both project participants and superordinate organizations influence the formation of project ventures. We propose that performance-outcome learning depends on the perceived relevance of prior performance and on organizational control over project participants. We examine this framework using data on 239 U.S. movie projects from the years 1931-40. In keeping with our theory, higher project performance led to future collaborations with the same partners, contingent on prior collaborations, project similarity, and organizational control. Our findings imply distinct patterns of network evolution and unfolding adaptation of hybrid-project systems through slow-moving, local adjustments

Original Article

The employment of malaria therapy for neurosyphilis has been decreasing since penicillin and other antibiotics appeared and neurosyphilis patients decreased recently in their number. But malaria therapy is one of the most effective therapies for neurosyphilis still now. So we must find out how to keep alive malaria blood not in vivo, simply. The results were: 1) The temperature in which malaria blood was kept, decided its fate. The preservation under 4℃, -20℃ was not suitable to keep alive malaria blood long. 2) The solution in a ratio of 4 parts of malaria blood to I part of ACD solution (anti-coagulant) was added by 1.2 to 2.5 mol. amounts of glycerin and then freezing it rapidly at a temperature of -79℃, quick thawing and injecting it intramuscularly among 65 subjects, infection was accomplished sufficiently in 54 subjects with no malaria history. The storage period was 3-242 days. Its incubation period was 12 to 28 days and the average 14.6 days. At present, the longest preservation period is 242 days. In case of slight prolongation of incubation subsequent to long preservation and the parasites figures of smears of Giemsa method, there is possibility of longer preservation than 242 days which is the longest period at this time. This method is simple, practical for malaria preservation. In this case, the factors to determine whether the blood was effectable or not effectable concerned the numbers of parasites in the blood before frozen. 3) Although the freezing drying method did not succeed this time, its possibility can be expected by observing the reconstruction of malaria parasites in glycerin using example. 4) As author described above, glycerin acts effectively on frozen-keeping of malaria protozoa, too

Additional file 1 of Association of anthropometric measures with all-cause and cause-specific mortality in US adults: revisiting the obesity paradox

Supplementary Material 1

Hydrogen and Methanol Exchange Processes for (TMP)Rh-OCH₃(CH₃OH) in Binary Solutions of Methanol and Benzene

Tetramesityl porphinato rhodium(III) methoxide ((TMP)Rh-OCH3) binds with methanol in benzene to form a 1:1 methanol complex ((TMP)Rh-OCH3(CH3OH)) (1). Dynamic processes are observed to occur for the rhodium(III) methoxide methanol complex (1) that involve both hydrogen and methanol exchange. Hydrogen exchange between coordinated methanol and methoxide through methanol in solution results in an interchange of the environments for the non-equivalent porphyrin faces that contain methoxide and methanol ligands. Interchange of the environments of the coordinated methanol and methoxide sites in 1 produces interchange of the inequivalent mesityl o-CH3 groups, but methanol ligand exchange occurs on one face of the porphyrin and the mesityl o-CH3 groups remain inequivalent. Rate constants for dynamic processes are evaluated by full line shape analysis for the 1H NMR of the mesityl o-CH3 and high field methyl resonances of coordinated methanol and methoxide groups in 1. The rate constant for interchange of the inequivalent porphyrin faces is associated with hydrogen exchange between 1 and methanol in solution and is observed to increase regularly with the increase in the mole fraction of methanol. The rate constant for methanol ligand exchange between 1 and the solution varies with the solution composition and fluctuates in a manner that parallels the change in the activation energy for methanol diffusion which is a consequence of solution non-ideality from hydrogen bonded clusters

Regioselectivity and Equilibrium Thermodynamics for Addition of Rh−OH to Olefins in Water

Rhodium(III) tetra(p-sulfonato phenyl) porphyrin ((TSPP)Rh) aquo and hydroxo complexes react with a series of olefins in water to form β-hydroxyalkyl complexes. Addition reactions of (TSPP)Rh−OH to unactivated terminal alkenes invariably occur with both kinetic and thermodynamic preferences to place rhodium on the terminal carbon to form (TSPP)Rh−CH2CH(OH)R complexes. Acrylic and styrenic olefins initially react to place rhodium on the terminal carbon to form Rh−CH2CH(OH)X as the kinetically preferred isomer but subsequently proceed to an equilibrium distribution of regioisomers where Rh−CH(CH2OH)X is the predominant thermodynamic product. Equilibrium constants for reactions of the diaquo rhodium(III) compound ([(TSPP)RhIII(H2O)2]-3) in water with a series of terminal olefins that form β-hydroxyalkyl complexes were directly evaluated and used in deriving thermodynamic values for addition of the Rh−OH unit to olefins. The ΔG° for reactions of the Rh−OH unit with olefins in water is approximately 3 kcal mol-1 less favorable than the comparable Rh−H reactions in water. Comparisons of the regioisomers and thermodynamics for addition reactions of olefins with Rh−H and Rh−OH units in water are presented and discussed

Multidomain Legendre-Galerkin Chebyshev collocation least squares method for one-dimensional problems with two nonhomogeneous jump conditions

Multidomain Legendre-Galerkin Chebyshev collocation least squares method for one-dimensional problems with two nonhomogeneous jump condition

Comparison of Rh−OCH₃ and Rh−CH₂OH Bond Dissociation Energetics from Methanol C−H and O−H Bond Reactions with Rhodium(II) Porphyrins

Reaction of methanol in toluene with tetramesityl rhodium(II) porphyrin ((TMP)RhII•) produces a 1H NMR-observable equilibrium with rhodium methoxide ((TMP)Rh−OCH3(CH3OH)) and rhodium hydride ((TMP)Rh−H) complexes. Equilibrium concentrations for each of these species, obtained from integration of 1H NMR spectra, were used in determining the equilibrium constant, K(298 K) = [Rh−OCH3(CH3OH)][Rh−H]/[RhII•]2[CH3OH]2 = 3.0(0.3), and free energy change, ΔG0(298 K) = −0.65(0.5) kcal mol−1, for the reaction. Equilibrium thermodynamic measurements in CD2Cl2 give ΔG0(298 K) = −5.5(0.2) kcal mol−1 for association of methanol with (TMP)Rh−OCH3 to form the six-coordinate 18-electron complex (TMP)Rh−OCH3(CH3OH). Equilibrium measurements in conjunction with (TMP)Rh−H and CH3O−H bond energetics are used to evaluate the (TMP)Rh−OCH3 bond dissociation free energy (Rh−OCH3 BDFE(298 K) = 38 (1.3) kcal mol−1), which is 15 kcal mol−1smaller than the Rh−H BDFE and approximately equal to the Rh−CH2OH BDFE

Formation and Interconversion of Organo-Cobalt Complexes in Reactions of Cobalt(II) Porphyrins with Cyanoalkyl Radicals and Vinyl Olefins

Observation of the formation and interconversion of organo-cobalt complexes ((TMP)Co-R) is used to reveal mechanistic features in the living radical polymerization (LRP) of methyl acrylate (MA) mediated by cobalt porphyrins. Both dissociative and associative exchange of radicals in solution with organo-cobalt complexes contribute to controlling the radical polymerization. The sequence of organo-cobalt species formed during the induction period for the (TMP)Co-R mediated LRP of MA indicates that homolytic dissociation is a prominent pathway for the interconversion of organo-cobalt complexes which contrasts with the corresponding vinyl acetate (VAc) system where associative radical exchange totally dominates these processes. The dissociation equilibrium constant (Kd(333 K)) for organo-cobalt complexes formed in methyl acrylate polymerization ((TMP)Co-CH(CO2CH3)CH2P) was estimated as 1.15 × 10−10 from analysis of the polymerization kinetics and 1H NMR. The ratio of the rate constants (333 K) for the cyanoisopropyl radical (•C(CH3)2CN) adding with monomer (k1) to the process of transferring a hydrogen atom to (TMP)CoII• (k2) was evaluated for the methyl acrylate system as 2 × 10−3 which is larger than that for vinyl acetate LRP (9 × 10−5). Kinetic analysis places the rate constant for associative radical interchange (333 K) at ∼7 × 105 M−1 s−1. The larger radical stabilization energy and lower energy of the singly occupied molecular orbital (SOMO) for methyl acrylate based radicals (•CH(CO2CH3)CH2P) compared to vinyl acetate contribute to the observed prominence of organo-cobalt homolytic dissociation and much smaller chain transfer which result in substantially better control for living radical polymerization of methyl acrylate than that observed for vinyl acetate

Table_2_Strategies of tree species to adapt to drought from leaf stomatal regulation and stem embolism resistance to root properties.xlsx

Considerable evidences highlight the occurrence of increasing widespread tree mortality as a result of global climate change-associated droughts. However, knowledge about the mechanisms underlying divergent strategies of various tree species to adapt to drought has remained remarkably insufficient. Leaf stomatal regulation and embolism resistance of stem xylem serves as two important strategies for tree species to prevent hydraulic failure and carbon starvation, as comprising interconnected physiological mechanisms underlying drought-induced tree mortality. Hence, the physiological and anatomical determinants of leaf stomatal regulation and stems xylem embolism resistance are evaluated and discussed. In addition, root properties related to drought tolerance are also reviewed. Species with greater investment in leaves and stems tend to maintain stomatal opening and resist stem embolism under drought conditions. The coordination between stomatal regulation and stem embolism resistance are summarized and discussed. Previous studies showed that hydraulic safety margin (HSM, the difference between minimum water potential and that causing xylem dysfunction) is a significant predictor of tree species mortality under drought conditions. Compared with HSM, stomatal safety margin (the difference between water potential at stomatal closure and that causing xylem dysfunction) more directly merge stomatal regulation strategies with xylem hydraulic strategies, illustrating a comprehensive framework to characterize plant response to drought. A combination of plant traits reflecting species’ response and adaptation to drought should be established in the future, and we propose four specific urgent issues as future research priorities.</p