Naringenin Induces ROS-Mediated ER Stress,Autophagy, and Apoptosis in Human Osteosarcoma Cell Lines

Osteosarcoma, a primary bone tumor, responds poorly to chemotherapy and radiation therapy in children and young adults; hence, as the basis for an alternative treatment, this study investigated the cytotoxic and antiproliferative effects of naringenin on osteosarcoma cell lines, HOS and U2OS, by using cell counting kit-8 and colony formation assays. DNA fragmentation and the increase in the G2/M phase in HOS and U2OS cells upon treatment with various naringenin concentrations were determined by using the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay and Annexin V/propidium iodide double staining, respectively. Flow cytometry was performed, and 2′,7′-dichlorodihydrofluorescein diacetate, JC-1, and Fluo-4 AM ester probes were examined for reactive oxygen species (ROS) generation, mitochondrial membrane potential, and intracellular calcium levels, respectively. Caspase activation, cell cycle, cytosolic and mitochondrial, and autophagy-related proteins were determined using western blotting. The results indicated that naringenin significantly inhibited viability and proliferation of osteosarcoma cells in a dose-dependent manner. In addition, naringenin induced cell cycle arrest in osteosarcoma cells by inhibiting cyclin B1 and cyclin-dependent kinase 1 expression and upregulating p21 expression. Furthermore, naringenin significantly inhibited the growth of osteosarcoma cells by increasing the intracellular ROS level. Naringenin induced endoplasmic reticulum (ER) stress-mediated apoptosis through the upregulation of ER stress markers, GRP78 and GRP94. Naringenin caused acidic vesicular organelle formation and increased autophagolysosomes, microtubule-associated protein-light chain 3-II protein levels, and autophagy. The findings suggest that the induction of cell apoptosis, cell cycle arrest, and autophagy by naringenin through mitochondrial dysfunction, ROS production, and ER stress signaling pathways contribute to the antiproliferative effect of naringenin on osteosarcoma cells.     

Trace analysis of sulfonylurea herbicides and their metabolites in water using a combination of off-line or on-line solid-phase extraction and liquid chromatography–tandem mass spectrometry

Two alternatives for the rapid simultaneous quantification of six sulfonylurea herbicides and five of their main degradation products in natural water are proposed. For concentration, the compounds were extracted on a polystyrene–divinylbenzene solid phase under pH and elution conditions that suppressed any hydrolysis. The eluates were analysed by liquid chromatography coupled to electrospray tandem mass spectrometry within 20 min. The whole method was validated and shown to give no hydrolysis artefacts. The application of off-line and on-line SPE of sulfonylureas enabled the 0.1 μg L⁻¹ and 1 ng L⁻¹ LOQ levels to be reached, respectively. The on-line SPE–LC–MS–MS method allowed the accurate quantitation of all sulfonylureas and three degradation products at 0.1 μg L⁻¹ or below in natural water, with an average repeatability of 8%.     

Water Absorption into Construction Materials: Comparison of Neutron Radiography Data with Network Absorption Models

Two different porous building materials have been previously measured and analysed (El-Abd and Milczarek, 2004, IEEE Trans. Nuclear Sci.; El-Abd et al., 2004, J. Phys. D) using neutron radiography to measure the water front position over time. The results from this experimental approach show a similar behaviour to the predictions from idealised model structures, in that there is a cross over point where the fastest rate of absorption at first favours the finer structure material and at later times favours the coarser pore structure material. The computer model, Pore-Cor** is used to generate the idealised structures and the absorption of fluid into porous structures follows a Bosanquet wetting algorithm for fluids undergoing both inertial and viscous dynamical flow (Ridgway and Gane, 2002, Colloids Surfaces A: Physicochem. Eng. Aspects 206, 217–239.). The model structures comprise cubic pores connected by cylindrical throats on a three-dimensional 10× 10× 10 position matrix simulating the void structure of porous media by fitting as closely as possible the modelled mercury intrusion curve to that of the experimentally determined mercury intrusion curve of the actual sample. They show the transition that occurs in the absorption behaviour from the linear t-dependent short timescale inertial regime to the familiar √t Lucas-Washburn viscous regime. The simulated absorption algorithm applied to these model structures also shows a fluid position behaviour that replicates qualitatively, given the limitation of representative sample volume, the cross over seen experimentally. Furthermore, the existence of a preferred wetting path is demonstrated in the experimental as well as the model wetting front behaviour. In the case of the structure containing the broader range of pore sizes, the wetting front is considered to proceed by a network of optimal size combinations (inertial wetting versus viscous drag) and connectivity, leaving some pores behind the wetting front unfilled or only partially filled. ** Pore-Cor is a software program of the Environmental and Fluids Modelling Group, University of Plymouth, Devon, PL4 8AA, U.K.     

Dynamic Scheduling of a Multiclass Fluid Model with Transient Overload

We study the optimal dynamic scheduling of different requests of service in a multiclass stochastic fluid model that is motivated by recent and emerging computing paradigms for Internet services and applications. In particular, our focus is on environments with specific performance guarantees for each class under a profit model in which revenues are gained when performance guarantees are satisfied and penalties are incurred otherwise. Within the context of the corresponding fluid model, we investigate the dynamic scheduling of different classes of service under conditions where the workload of certain classes may be overloaded for a transient period of time. Specifically, we consider the case with two fluid classes and a single server whose capacity can be shared arbitrarily among the two classes. We assume that the class 1 arrival rate varies with time and the class 1 fluid can more efficiently reduce the holding cost. Under these assumptions, we characterize the optimal server allocation policy that minimizes the holding cost in the fluid model when the arrival rate function for class 1 is known. Using the insights gained from this deterministic case, we study the stochastic fluid system when the arrival rate function for class 1 is random and develop various policies that are optimal or near optimal under various conditions. In particular, we consider two different types of heavy traffic regimes and prove that our proposed policies are strongly asymptotically optimal. Numerical examples are also provided to demonstrate further that these policies yield good results in terms of minimizing the expected holding cost.     

Synthesis and properties of poly(1-phenyl-1-octyne)s containing stereogenic and chromophoric pendant groups

Poly(1-phenyl-1-octyne)s containing different stereogenic and chromophoric pendants {-[(C6H13)C=C(C6H4-p-CO2-R)]n-R=[(1S)-endo]-(-)-borneyl (P3), (1R,2S,5R)-(-)-menthyl (P4),―C6H4-p-(1R,2S,5R)-(-)-menthyl (P5), 2-napthyl (P6), 4-biphenylyl (P7)} have been designed and synthesized. The polymers are prepared in moderate yields by WCl6-Ph4Sn and possess high molecular weights (Mw up to 64000). The structures and properties of the polymers are characterized and evaluated by NMR, TGA, UV, CD, PL, and EL analyses...     

New aerobic oxidation of benzylic compounds: efficient catalysis by N-hydroxy-3,4,5,6-tetraphenylphthalimide (NHTPPI)/CuCl under mild conditions and low catalyst loading

Efficient aerobic oxidation of benzylic compounds using NHTPPI, a new NHPI analogue, as a key catalyst combined with CuCl, have been achieved under mild conditions and using as little as 1 mol% catalyst.