Characteristics and Stocks of Soil Nutrient under Various Land Use Types in a Super Wet Tropical Rain Forest Padang, West Sumatra

In order to clarify the characteristics and stocks of soil nutrient under various land use types in a super wet tropical rain forest in Padang, West Sumatera. We investigated the nutrient characteristics of the several samples of soils under different land use such as cacao plantation (CP), cinnamon plantation (CMP), mixed garden (MG), and primary forest (PF) in Gadut Mountain, Padang, West Sumatra. The soil nutrient characteristics varied among the different land use types. The range of nutrient characteristics under four land use type were 4.60 – 7.01% and 0.4 – 0.60 % for total carbon and total nitrogen and were 9.80 – 24.59, 0.68 – 2.07 and 0.30 – 0.8 mol (+) kg-1 for Ca, Mg and K, respectively. The highest content of soil nutrient status was found under MG, while the lowest soil nutrient status found at PF. This result indicated that the MG with various vegetation types might contribute in enriching the organic matter in soil. The soil nutrient content such as TN, exchangeable Ca, Mg and K tended to decrease with soil depth of each land use type. However, the sodium (Na) content in soil tended to increase within the soil depth. These were presumably due to evaporation of Na at surface soil within the study area was low. These study results showed that spatially the nutrient properties of soil were closely related to the land use type and management practices. It was suggested that the nutrient characteristics of soils under various land use types in a super wet tropical rain forest region, in Gadut Mountain, Padang West Sumatra were significantly affected by the land use types and land coverage

Aldo–Keto Reductase 1B10 and Its Role in Proliferation Capacity of Drug-Resistant Cancers

The human aldo–keto reductase AKR1B10, originally identified as an aldose reductase-like protein and human small intestine aldose reductase, is a cytosolic NADPH-dependent reductase that metabolizes a variety of endogenous compounds, such as aromatic and aliphatic aldehydes and dicarbonyl compounds, and some drug ketones. The enzyme is highly expressed in solid tumors of several tissues including lung and liver, and as such has received considerable interest as a relevant biomarker for the development of those tumors. In addition, AKR1B10 has been recently reported to be significantly up-regulated in some cancer cell lines (medulloblastoma D341 and colon cancer HT29) acquiring resistance toward chemotherapeutic agents (cyclophosphamide and mitomycin c), suggesting the validity of the enzyme as a chemoresistance marker. Although the detailed information on the AKR1B10-mediated mechanisms leading to the drug resistance process is not well understood so far, the enzyme has been proposed to be involved in functional regulations of cell proliferation and metabolism of drugs and endogenous lipids during the development of chemoresistance. This article reviews the current literature focusing mainly on expression profile and roles of AKR1B10 in the drug resistance of cancer cells. Recent developments of AKR1B10 inhibitors and their usefulness in restoring sensitivity to anticancer drugs are also reviewed

Structural and dynamic behavior of lithium iron polysulfide Li₈FeS₅ during charge–discharge cycling

Lithium sulfide (Li₂S) is one of the promising positive electrode materials for next-generation rechargeable lithium batteries. To improve the electrochemical performance of electronically resistive Li₂S, a Fe-doped Li₂S-based positive electrode material (Li₈FeS₅) has been recently designed and found to exhibit excellent discharge capacity close to 800 mAh g⁻¹. In the present study, we investigate the structural and dynamic behavior of Li₈FeS₅ during charge–discharge cycling. In Li₈FeS₅, Fe ions are incorporated into the Li₂S framework structure. The Li₂S-based structure is found to transform to an amorphous phase during the charge process. The delithiation-induced amorphization is associated with the formation of S-S polysulfide bonds, indicating charge compensation by S ions. The crystalline to non-crystalline structural transformation is reversible, but Li ions are extracted from the material via a two-phase reaction, although they are inserted via a single-phase process. These results indicate that the delithiation/lithiation mechanism is neither a topotactic extraction/insertion nor a conversion-type reaction. Moreover, the activation energies for Li ion diffusion in the pristine, delithiated, and lithiated materials are estimated to be in the 0.30–0.37 eV range, which corresponds to the energy barriers for local hopping of Li ions along the Li sublattice in the Li₂S framework

Crystal Structure of the Complex between Calyculin A and the Catalytic Subunit of Protein Phosphatase 1

AbstractThe crystal structure of the catalytic subunit of the protein phosphatase 1 (PP1), PP1γ, in complex with a marine toxin, calyculin A, was determined at 2.0 Å resolution. The metal binding site contains the phosphate group of calyculin A and forms a tight network via the hydrophilic interactions between PP1 and calyculin A. Calyculin A is located in two of the three grooves, namely, in the hydrophobic groove and the acidic groove on the molecular surface. This is the first observation to note that the inhibitor adopts not a pseudocyclic conformation but an extended conformation in order to form a complex with the protein. The amino acid terminus of calyculin A contributes, in a limited manner, to the binding to PP1γ, which is consistent with findings from the studies of dose-inhibition analysis

CORONARY ARTERY MORPHPLOGY AND REACTIVITY TO ACUTE HYPOXIA IN CHRONIC PULMONARY DISEASE

In patients with chronic pulmonary disase (CPD), myocardial infarction is rare. To elucidate why this is so, we investigated the morphological changes and the reactivity of the coronary artery to acute hypoxia in patients with CPD. Sixty patients with CPD and 28 normal subjects were studied. Measurements of pulmonary homodynamics and coronary angiography were undertaken before and after inhalation of 13%O2 for 15 minutes. The size of the coronary arteries was measured using a densitometric method, and a coronary narrowing score was calculated according to the WHO criteria. The size of the left anterior descending artery of patients with low %VC and hypoxia was larger than that of the normal subjects. In patients with CPD, the coronary narrowing score was low and the atherosclerotic change was minimal. The reactivity of the coronary arteries to acute hypoxia was reduced in patients with CPD when compared with normal subjects