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Aqueous amino acid salts are considered as an attractive alternative to alkanolamine solvents (e.g., MEA) for carbon dioxide (CO2) absorption. The kinetics of CO2 into unloaded aqueous solutions of potassium lysinate (LysK) was studied using a wetted wall column at concentrations ranging from 0.25 to 2.0 M and temperatures from 298 to 333 K. Physicochemical properties of aqueous LysK solutions such as density, viscosity, and physical solubility of CO2 were measured to evaluate the reaction rate constants. The reaction pathway is described using zwitterion mechanism taking into account the effect of ionic strength on the reaction rate. Under the fast pseudo-first-order regime, the reaction rate parameters were obtained and correlated in a power-law reaction rate expression. LysK shows higher chemical reactivity toward CO2 than the industrial standard MEA and most of amino acid salts. Its reaction rate constants increase considerably with concentration and temperature. The reaction order is found to be an average value of 1.58 with respect to LysK. The forward second-order kinetic rate constant, k20, are obtained as 31615 and 84822 m³ kmol-1 s-1 at 298 and 313 K, respectively with activation energy of 51.0 kJ mol-1. The contribution of water to the zwitterion deprotonation seems to be more significant than that of LysK for the above-mentioned kinetic conditions. [ABSTRACT FROM AUTHOR]

Abscisic acid (ABA) regulates plant development and is crucial for plant responses to biotic and abiotic stresses. Studies have identified the key components of ABA signaling in Arabidopsis (Ambidopsis thaliana), some of which regulate ABA responses by the transcriptional regulation of downstream genes. Here, we report the functional identification of rice (Oryza sativa) ABI5-Like1 (ABL1), which is a basic region/leucine zipper motif transcription factor. ABL1 is expressed in various tissues and is induced by the hormones ABA and indole-3-acetic acid and stress conditions including salinity, drought, and osmotic pressure. The ABL1 deficiency mutant, abl1, shows suppressed ABA responses, and ABL1 expression in the Arabidopsis abi5 mutant rescued the ABA sensitivity. The ABL1 protein is localized to the nucleus and can directly bind ABA-responsive elements (ABREs; G-box) in vitro. A gene expression analysis by DNA chip hybridization confirms that a large proportion of down-regulated genes of abl1 are involved in stress responses, consistent with the transcriptional activating effects of ABLl. Further studies indicate that ABLl regulates the plant stress responses by regulating a series of ABRE-containing WRKY family genes. In addition, the abl1 mutant is hypersensitive to exogenous indole-3-acetic acid, and some ABRE-containing genes related to auxin metabolism or signaling are altered under ABL1 deficiency, suggesting that ABL1 modulates ABA and auxin responses by directly regulating the ABRE-containing genes. [ABSTRACT FROM AUTHOR]

We investigated the ceramide-induced apoptosis and potential mechanism in A-431 cells. Ceramide treatment causes the round up and the death of A-431 cells that is associated with p38 activation and can be observed in 10 h. Short-time ceramide treatment-induced cell death is not associated with the typical apoptotic phenotypes, such as the translocation of phosphatidylserine (PS) from inner layer to outer layer of the plasma membrane, loss of mitochondrial membrane potential, DNA fragmentation, caspase activation, and PARP or PKC-δ degradation. SB202190, a specific inhibitor of p38 mitogen-activated protein (MAP) kinase, but not caspase inhibitor, blocks the cell death induced by short-time ceramide treatment (within 12 h). Whereas neither inhibition of p38 MAP kinase nor inhibition of caspases blocks cell death induced by prolonged ceramide treatment. Moreover, incubation of cells with ceramide for a long time (over 12 h) results in the reduction of proportion of S phase accompanied with typical apoptotic cell death phenotypes that are different from the cell death induced by short-time ceramide treatment. Our data demonstrated that ceramide-induced apoptotic cell death involves both caspase-dependent and caspase-independent signaling pathways. The caspase-independent cell death that occurred in relatively early stage of ceramide treatment is mediated via p38 MAP kinase, which can progress into a stage that is associated with changes of cell cycle events and involves both caspase-dependent and -independent mechanisms. J. Cell. Physiol. 199: 47–56, 2004© 2003 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Triassic rare-metal pegmatite deposits are widespread in East Asia; e.g., the western Kunlun and Songpan-Ganze belt in northern Tibet and the Altai belt in the heart of the Central Asian Orogenic Belt. However, rare-metal enrichment processes and deposit formation mechanisms are enigmatic. Most rare-metal pegmatites in East Asia formed at ca. 220–200 Ma in the Late Triassic and are genetically related to S-type granites. Whole-rock and zircon Li and Cs contents indicate that sedimentary rocks represent a fertile rare-metal source for the pegmatite deposits and that long-term chemical weathering plays a key role in the enrichment of rare metals. The formation of these widespread deposits in East Asia was associated with lithospheric extension induced by slab retreat along the periphery of the supercontinent during Pangea assembly. [ABSTRACT FROM AUTHOR]

Phytochemical and pharmacological study on the rhizomes of Atractylodes lancea led to the identification of twenty-one compounds: six new eudesmane-type sesquiterpenoids (1-6), two new eremophilane-type sesquiterpenoids (7, 8), and thirteen known compounds (9-21). These new compounds were elucidated using extensive spectroscopic analyses with experimental and calculated electronic circular dichroism (ECD) for the configurational assignments. Notably, this study was the first report on the isolation of two eremophilane-type sesquiterpenoids (7, 8) from the genus Atractylodes. Compounds 5, 7, and 16 showed potent hepatoprotective activities against N-acetyl-p-aminophenol (APAP)-induced HepG2 cell injury at a concentration of 10 µM (bicyclol as the positive drug). [ABSTRACT FROM AUTHOR]

Objective LPS-treated PC12 cells were used to establish neuron inflammation model. RT-PCR was used to detect the mRNA of cytokines. CCK-8 assay was used to check determine cell viability. Western blot was used to detect NF-κB pathway. Methods LPS-treated PC12 cells were used to establish neuron inflammation model. RT-PCR was used to detect the mRNA of cytokines. CCK-8 assay was used to check determine cell viability. Western blot was used to detect NF-κB pathway. Results After 12 hrs treatment of PC12 cells with different doses of LPS (0, 100, 300 and 1 000 ng/mL), the mRNA level of TNF-α,IL-6 and IL-1β all increased. The cells pre-treated with different doses of gypenoside (30, 100 μg/mL) and then treated with LPS for 24 h, cell viability decreased to 85.7%. However, 30 and 100 μg/mL gypenoside pre-treatment resulted in cell viability increased to 96.2% and 97.9% respectively. Gypenoside also inhibited LPS-induced cell inflammation as indicated by increased mRNA level of TNF-α, IL-6 and IL-1β caused by LPS stimulation. LPS increased the phosphorylation of p65 (p-p65) and the phosporylation was also inhibited by gypenoside treatment. Conclusions Gypenoside alleviates LPS-induced inflammation and then protects PC12 cells from injury induced by LPS through inhibiting NF-κB pathway.

Diverse rock types and contrasting geochemical compositions of post-collisional mafic rocks across the Tibetan Plateau indicate that the underlying enriched lithospheric mantle is heterogeneous; however, how these enriched mantle sources were formed is still debated. The accreted terranes within the Tibetan Plateau experienced multiple stages of evolution. To track the geochemical characteristics of their associated lithospheric mantle through time, we can use mantlederived magmas to constrain the mechanism of mantle enrichment. We report zircon U-Pb ages, major and trace element contents, and Sr-Nd isotopic compositions for Early Cretaceous and late Eocene mafic rocks in the southern Qiangtang terrane. The Early Cretaceous Baishagang basalts (107.3 Ma) are characterized by low K2O/Na2O (<1.0) ratios, arc-like trace element patterns, and uniform Sr-Nd isotopic compositions [(87Sr/86Sr)i = 0.7067-0.7073, εNd(t) = -0.4 to -0.2]. We suggest that the Baishagang basalts were derived from partial melting of enriched lithospheric mantle that was metasomatized by subducted Bangong-Nujiang oceanic material. We establish the geochemistry of the pre-collisional enriched lithospheric mantle under the southern Qiangtang terrane by combining our data with those from other Early Cretaceous mafic rocks in the region. The late Eocene (ca. 35 Ma) post-collisional rocks in the southern Qiangtang terrane have low K2O/Na2O (<1.0) ratios, and their major element, trace element, and Sr-Nd isotopic compositions [(87Sr/86Sr)i = 0.7042-0.7072, εNd(t) = -4.5 to +1.5] are similar to those of the Early Cretaceous mafic rocks. Based on the distribution, melting depths, and wholerock geochemical compositions of the Early Cretaceous and late Eocene mafic rocks, we argue that the primitive late Eocene postcollisional rocks were derived from pre-collisional enriched lithospheric mantle, and the evolved samples were produced by assimilation and fractional crystallization of primary basaltic magma. Asthenosphere upwelling in response to the removal of lithospheric mantle induced the partial melting of enriched lithospheric mantle at ca. 35 Ma. [ABSTRACT FROM AUTHOR]