Hosting the plant cells in vitro : recent trends in bioreactors

Biotechnological production of high-value metabolites and therapeutic proteins by plant in vitro systems has been considered as an attractive alternative of classical technologies. Numerous proof-of-concept studies have illustrated the feasibility of scaling up plant in vitro system-based processes while keeping their biosynthetic potential. Moreover, several commercial processes have been established so far. Though the progress on the field is still limited, in the recent years several bioreactor configurations has been developed (e.g., so-called single-use bioreactors) and successfully adapted for growing plant cells in vitro. This review highlights recent progress and limitations in the bioreactors for plant cells and outlines future perspectives for wider industrialization of plant in vitro systems as “green cell factories” for sustainable production of value-added molecules

Structure and Properties of Dense Silica Glass

The O K-edge x-ray Raman scattering (XRS), Brillouin scattering and diffraction studies on silica glass at high pressure have been elucidated in a unified manner using model structures obtained from First-Principles molecular dynamics calculations. This study provides a comprehensive understanding on how the structure is related to the physical and electronic properties. The origin of the "two peak" pattern in the XRS is found to be the result of increased packing of oxygen near the Si and is not a specific sign for sixfold coordination. The compression mechanism involving the presence of 5- and 6-fold coordinated silicon is confirmed. A slight increase in the silicon-oxygen coordination higher than six was found to accompany the increase in the acoustic wave velocity near 140 GPa

Ordered GeSi nanorings grown on patterned Si (001) substrates

An easy approach to fabricate ordered pattern using nanosphere lithography and reactive iron etching technology was demonstrated. Long-range ordered GeSi nanorings with 430 nm period were grown on patterned Si (001) substrates by molecular beam epitaxy. The size and shape of rings were closely associated with the size of capped GeSi quantum dots and the Si capping processes. Statistical analysis on the lateral size distribution shows that the high growth temperature and the long-term annealing can improve the uniformity of nanorings

Observation of prolonged coherence time of the collective spin wave of atomic ensemble in a paraffin coated Rb vapor cell

We report a prolonged coherence time of the collective spin wave of a thermal 87Rb atomic ensemble in a paraffin coated cell. The spin wave is prepared through a stimulated Raman Process. The long coherence time time is achieved by prolonging the lifetime of the spins with paraffin coating and minimize dephasing with optimal experimental configuration. The observation of the long time delayed-stimulated Stokes signal in the writing process suggests the prolonged lifetime of the prepared spins; a direct measurement of the decay of anti-Stokes signal in the reading process shows the coherence time is up to 300 us after minimizing dephasing. This is one hundred times longer than the reported coherence time in the similar experiments in thermal atomic ensembles based on the Duan-Lukin-Cirac-Zoller (DLCZ) and its improved protocols. This prolonged coherence time sets the upper limit of the memory time in quantum repeaters based on such protocols, which is crucial for the realization of long-distance quantum communication. The previous reported fluorescence background in the writing process due to collision in a sample cell with buffer gas is also reduced in a cell without buffer gas.Comment: 4 pages, 4 figure

Low Concentrations of Corticosterone Exert Stimulatory Effects on Macrophage Function in a Manner Dependent on Glucocorticoid Receptors

Endogenous glucocorticoids (GCs) have both stimulatory and suppressive effects on immune cells depending on the concentration. However, the mechanisms underlying the stimulatory effects of GCs remain elusive. Rat peritoneal macrophages were treated with different concentrations of corticosterone (0, 30 nM, 150 nM, and 3 μM). To inhibit the glucocorticoid receptor (GR) activity, macrophages were preincubated with the GR antagonist RU486 (mifepristone, 10 μM) for 30 min before treatment with corticosterone (150 nM). In the absence of immune stimuli, the chemotactic and phagocytic activities of macrophages were markedly enhanced by low concentrations of corticosterone (30 and 150 nM) when compared with vehicle-treated controls. However, these effects were not observed at a high concentration of corticosterone (3 μM). Furthermore, blocking GR activity inhibited 150 nM corticosterone-enhanced chemotaxis and phagocytosis of macrophages. Meanwhile, after treatment with corticosterone (150 nM) for 1 h and 3 h, GR protein expression increased to 1.4- and 2.2-fold, respectively, compared to untreated macrophages. These effects were inhibited by RU486. However, mineralocorticoid receptor (MR) protein expression was not influenced by 150 nM corticosterone. These results demonstrate that low concentrations of corticosterone exert stimulatory effects on macrophage function in the absence of immune stimuli, and GR is at least partially responsible for these effects

Inhibition of tumor cell proliferation and induction of apoptosis in 95-D lung cancer cells by drimartol A from hairy root cultures of Artemisia annua

Drimartol A (DA), a sesquiterpene courmarin ether, was isolated from the cultured hairy roots of A. annua for the first time, and no biological activity of DA has ever been reported. In this work, DA was shown to possess interesting cytotoxic activities against the human tumor cell lines of HO8910 (ovary), 95-D (lung), QGY (liver) and HeLa (cervix) by MTT assay, whose IC50 values were ranged within 17.94-22.3 μM for 24h. Given that treatment of lung cancer is a priority of our interest, induction of apoptosis by DA in the human lung tumor cell line 95-D was focused. The 95-D cell growth was inhibited in a time dependent manner and its cell cycle was arrested in the G2 phase by DA. The apoptotic rate of the cells increased in a dose-dependent manner. DA also increased the activity of caspase-9 and -3 and caused a decrease in the mitochondrial membrane potential. These results revealed that DA could efficiently induce 95-D cell apoptosis through mitochondrial dependent pathway, and it may be a potential chemotherapeutic agent.Colegio de Farmacéuticos de la Provincia de Buenos Aire