Rat astrocytes, immunologically competent glial cells of the central nervous system (CNS), released a variety of cytokines after activation. Lipopolysaccharidestimulated astrocytes produced tumor necrosis factor (TNF) as demonstrated by Northern blot analysis using a mouse TNF probe and by functional assay. Biological activity of rat astrocyte-derived TNF was neutralized by rabbit antiserum against recombinant murine TNF. Stimulation of astrocytes by lipopolysaccharide also activated the interleukin 1 and interleukin 6 genes. We have also investigated whether a neurotropic paramyxovirus, Newcastle disease virus, triggers cytokine production by astrocytes. This virus induced astrocytes to produce TNF, lymphotoxin, interleukin 6, and a-and 13-interferons.Thus, stimulation by endotoxin and virus activated distinct, yet overlapping, sets of cytokine genes. We propose that astrocytes and the cytokines they produce may play a significant role in the pathogenesis of immunologically and/or virally mediated CNS disease, in CNS intercellular communication, and in the interactions between the nervous and immune systems.Astrocytes are macroglial cells of the central nervous system (CNS) that express a variety of immunological characteristics. Astrocytes stimulated with y-interferon (IFN-y) express class I and class II major histocompatibility complex (MHC) antigens in rodents (1-3). Astrocytes expressing class II antigens can present foreign antigen to T cells in a MHCrestricted fashion (3,4). Lipopolysaccharide (LPS) stimulates astrocytes to produce prostaglandins (5), complement components C3 and factor B (6), and cytokines with biological activities similar to interleukin 1 (IL-1) (5) and IL-3 (7). These observations indicate that astrocytes are immunologically competent cells that share many important functional characteristics with macrophages.Accumulating evidence has revealed that astrocytes, like macrophages (8) MATERIALS AND METHODSCell Cultures. Primary cultures of rat astrocytes were established as described (13) (13). WEHI 164 clone 13, a murine fibrosarcoma line (14), was used for TNF functional assays.RNA Preparation and Analysis. Total RNA was isolated from cells by the guanidinium isothiocyanate method (15). RNA was denatured by formaldehyde treatment, electrophoresed through a 0.8% agarose gel, and transferred to nitrocellulose as described (16,17). The transferred RNA blots were hybridized with probes of high specific activity. Membranes probed with 32P-labeled DNA fragments were hybridized for 2 days at 370C and washed at 550C, twice in 2X SSC (ix SSC = 0.15 M NaC1/0.015 M sodium citrate)/0.1% SDS and twice in 0.5x SSC/0.1% SDS. Membranes probed with 32P-labeled RNA were hybridized overnight at 650C and washed at 650C as described above.Probes. Mouse cytokine probes were used in all experiments. DNA probes for IL-la, IL-1f3, IL-3, and lymphotoxin were constructed by using an oligolabeling reaction kit (Pharmacia), and RNA probes for TNF and the type I IFN were prepared using an RNA probe vector s...

Effect of Pt bottom electrode texture selection on the tetragonality and physical properties of Ba0.8Sr0.2TiO3 thin films produced by pulsed laser deposition J. Appl. Phys. 112, 044105 (2012) Relationship between dielectric coefficient and Urbach tail width of hydrogenated amorphous germanium carbon alloy films Appl. Phys. Lett. 101, 042109 (2012) Interfacial oxide re-growth in thin film metal oxide III-V semiconductor systemsThe contrast mechanisms of domain imaging experiments assisted by atomic force microscope ͑AFM͒ have been investigated by model experiments on nonpiezoelectric ͑silicon oxide͒ and piezoelectric ͓Pb͑Zr,Ti͒O 3 ͔ thin films. The first step was to identify the electrostatic charge effects between the tip, the cantilever, and the sample surface. The second step was to explore the tipsample piezoelectric force interaction. The static deflection of the cantilever was measured as a function of dc bias voltage (V dc ) applied to the bottom electrode ͑n-type Si wafers͒ for noncontact and contact modes. In addition, a small ac voltage (V ac sin t) was applied to the tip to measure the amplitude (A ) and phase (⌽ ) of the first harmonic ͑͒ signal as a function of V dc . By changing from the noncontact to the contact mode, a repulsive contribution to the static deflection was found in addition to the attractive one and a 180°phase shift in ⌽ was observed. These results imply that in the contact mode the cantilever buckling is induced by the capacitive force between the cantilever and the sample surface. This interaction adds to the tip-sample piezoelectric interaction thereby overlapping the obtained tip vibration signal. Therefore, the antiparallel ferroelectric domain images obtained at zero dc bias voltage will show a variation in A but a negligible one in ⌽ . The capacitive force contribution to the tip vibration signal was further verified in piezoelectric hysteresis loop measurement assisted by the AFM. The observed vertical offset of the loops was explained by the contact potential difference between the cantilever and the bottom electrode. The shape of the curve could be explained by the capacitive force interaction combined with the tip-sample piezoelectric interaction. The experimental results obtained in this study support the interpretation of the cantilever-sample capacitive force contribution to the tip vibration signal in ferroelectric domain imaging experiments using AFM as a probing tool. The use of a large area top electrode between the tip and the sample resulted in the elimination of the electrostatic cantileversample interaction with negligible degradation of the domain contrast. This method proved to be successful because the cantilever-sample interaction was hardly detected and only the tip-sample interaction was observed.

trolled using a closed-cycle Helium cryostat (Cryogenic Technology Inc., model 501A).Theoretical Methodology: The geometry of all compounds was fully optimized with the semiempirical PM3 (Parametric Method 3) Hamiltonian [26], which yields a coplanar structure. The vibrational frequencies were also computed at this level of theory and confirm the global minimum of the equilibrium geometry by the absence of negative frequencies. The geometric relaxation taking place in the lowest excited state has been described by coupling the PM3 method to a full CI (configuration interaction) expansion involving a limited number of orbitals (as implemented in the AMPAC package) [27]. The size of the CI active space is chosen in order to ensure the convergence of the geometric parameters. On the basis of the PM3-optimized structures, the transition energy and transition dipole moment associated to the lowest excited state of the compounds have been estimated with the help of the spectroscopic version of the semiempirical These efforts span not only layer-structured materials, but also metallic, semiconducting, and even strongly ionic bonded oxide materials. The latter, however, have often been found as nanosized tubular materials. Nanotubes and/or nanotubular oxide (and, in particular, functional oxide) materials that have particularly promising physical properties and potential applications in nanoelectronics, however, are rarely found or synthesized. Nanotubes of SiO 2 , TiO 2 , and vanadium oxides have been synthesized, using several different processing techniques. Among these, nanotubes of TiO 2 have been the most intensively investigated, since their superior catalytic properties are combined with nanotubular forms of high surface area. Much effort has been devoted to forming TiO 2 nanotubes, and nanotubular COMMUNICATIONS

Macrophages play an important role in the acute tissue inflammatory response through the release of cytokines and growth factors in response to stimuli such as lipopolysaccharide (LPS). Macrophage inflammatory effector functions are also influenced by interactions with the extracellular matrix (ECM). Such macrophage-ECM interactions may be important in regulating chronic inflammatory responses. Recent evidence has suggested that hyaluronan (HA), a glycosaminoglycan (GAG) component of ECM can induce inflammatory gene expression in murine macrophages. HA exists in its native form as a large polymer, but is found as smaller fragments under inflammatory conditions. The NF-kappa B/I-kappa B transcriptional regulatory system has been shown to be a critical component of the host inflammatory response. We examined the effects of high molecular weight HA and lower molecular weight HA fragments on NF-kappa B activation in mouse macrophages. Only the smaller HA fragments were found to activate NF-kappa B DNA binding activity. After HA stimulation, I-kappa B alpha mRNA was induced and I-kappa B alpha protein levels, which initially decreased, were restored. The induction of I-kappa Balpha expression was not observed for other GAGs. The time course of I-kappa B alpha protein regeneration in response to HA fragments was consistent with an autoregulatory mechanism. In support of this mechanism, in vitro translated murine I-kappa B alpha inhibited HA fragment-induced NF-kappa B DNA binding activity. The NF-kappa B DNA binding complex in HA-stimulated extracts was found to contain p50 and p65 subunits. Activation of the NF-kappa B/I-kappa B system in macrophages by ECM fragments may be an important mechanism for propagating the tissue inflammatory response.

For scalable perovskite solar cells (PSCs), deposition of a homogeneous and high-quality perovskite film on a large area (>100 cm 2 ) is a prerequisite. Conventional solutions for spin-coating on small areas usually contain polar aprotic solvents with high boiling point, which is difficult to adopt for large-area bar coating because of the uncontrollable and slow drying process due to the strong interaction between polar aprotic solvent and Lewis acidic PbI 2 or perovskite. Thus, the precursor solution plays a vital role in the success of largearea coating. Here we report a coating solution suitable for large-area perovskite films. The coating solutions prepared via gas-mediated solid−liquid conversion contain preformed perovskite clusters as confirmed by rotational mode of methylammonium cation in the PbI 3 − framework from Raman spectroscopy. CH 3 NH 3 PbI 3 (MAPbI 3 ) films formed by D-bar coating within 20 s on the area over 100 cm 2 exhibit tetragonal/cubic superlattice structure with highly preferred orientation in the entire film, which results in average power conversion efficiency (PCE) of 17.01% and best PCE of 17.82%.

We investigated the surface potential of the ferroelectric domains of the epitaxial PbTiO3 (PTO) films using both Kelvin probe and piezoresponse force microscopy. The surface potential changes as a function of applied biases suggested that the amount and sign of surface potentials depend on the correlation between polarization and screen charges. It also suggested that the trapped negative charges exist on the as-deposited PTO surfaces. Injected charges and their resultant surface potentials are investigated by grounded tip scans. The results unveiled the origin of surface potential changes during ferroelectric switching in the epitaxial PTO films.

The fifth component of guinea pig complement, with a sedimentation coefficient 7.8S, is cleaved by sensitized sheep erythrocytes treated with the first four components of complement into two fragments with sedimentation coefficients of 7.4S and 1.5S. The smaller fragment, with a molecular weight of about 15,000, possesses chemotactic activity for rabbit polymorphonuclear leukocytes, as well as anaphylatoxic activity for guinea pig ileum.

Self-assembled monolayers (SAMs) bearing sulfonate (-SO3H) surface functional groups, on single-crystal Si wafers, were used as substrates for the deposition of TiO2 thin films from aqueous solutions. Polycrystalline TiO2 thin films over 50 nm thick formed in 2 h by hydrolysis of TiCl4 in aqueous HCI solutions at 80 °C. The films were pore-free, showed excellent adherence and uniformity, and consisted of anatase crystallites 2–4 nm in diameter. Annealing at temperatures up to 600 °C caused coarsening of the anatase grains, but no loss of adherence or structural integrity.