Activation Composite 2014 Key Free
In this paper, magnesium matrix hydroxyapatite composite material was prepared by electrophoretic deposition method. The optimal process parameters of electrophoretic deposition were HA suspension concentration of 0.02 kg/L, aging time of 10 days and voltage of 60 V. Animal experiment and SBF immersion experiment were used to test the biocompatibility and bioactivity of this material respectively. The SD rats were divided into control group and implant group. The implant surrounding tissue was taken to do tissue biopsy, HE dyed and organizational analysis after a certain amount of time in the SD rat body. The biological composite material was soaked in SBF solution under homeothermic condition. After 40 days, the bioactivity of the biological composite material was evaluated by testing the growth ability of apatite on composite material. The experiment results showed that magnesium matrix hydroxyapatite biological composite material was successfully prepared by electrophoretic deposition method. Tissue hyperplasia, connective tissue and new blood vessels appeared in the implant surrounding soft tissue. No infiltration of inflammatory cells of lymphocytes and megakaryocytes around the implant was found. After soaked in SBF solution, a layer bone-like apatite was found on the surface of magnesium matrix hydroxyapatite biological composite material. The magnesium matrix hydroxyapatite biological composite material could promot calcium deposition and induce bone-like apatite formation with no cytotoxicity and good biocompatibility and bioactivity.
Activation Composite 2014 Key
The various modifications made to bulk-fill composite resins using different fillers, photoinitiators, and monomers from conventional composites are expected to reduce contraction stress and increase composite resins' polymerization. There are various types of bulk-fill composite resins based on their viscosity, namely, low, medium, and high viscosities and sonic-activated bulk-fill composite resins. The filler size in low-viscosity bulk-fill composite resin will reduce the spread of light between the filler and the matrix so that light penetration can be more in depth. High-viscosity bulk-fill composite resin, ivocerine, is used as a photoinitiator aiming to increase the degree of polymerization. Even now, an instrument has been developed to condense the material with a vibration technique on composite resin application; this method uses ultrasonic power.
The polymerization quality of the composite resin can be assessed directly or indirectly. The straightforward method for assessing a degree of conversion resonance imaging, optical microscopy, and Raman or Fourier transform infrared spectroscopy, whereas indirect methods include visual inspection, surface hardness consisting of ISO 4049 scraping method, and Vickers microhardness ratio. The Vickers microhardness method in this study was used to evaluate the depth of cure of bulk-fill composite resin because it is easier to apply than other methods. Microhardness measurements can be carried out on research samples with the Vickers test to obtain Vickers hardness ratio (VHR) data.
Several factors can influence DoC, namely, the light source used, intensity, wavelength, irradiation time, light tip size, irradiation method, chemical formulation of the organic matrix, distribution and amount of inorganic filler, type and amount of photoinitiator, and color of composite resin. The low DoC indicates the low polymerization quality that a lot of free or unreacted monomer during the polymerization process.
Indentation results on sonically activated bulk-fill composite resin at a thickness of 2 mm on the top and bottom surface (a), 4 mm on the top and bottom surface (b); low-viscosity bulk-fill composite resin at a thickness of 2 mm on top and bottom surface (c), a thickness of 4 mm on top and bottom surface (d); high-viscosity bulk-fill composite resin at a thickness of 2 mm on top and bottom surface (e), and thickness of 4 mm on top and bottom surface (f)
Filler influenced the difference in the depth of cure and the characteristics of the bulk-fill composite in terms of size, volume, and weight. Comparison of microhardness of high-viscosity bulk-fill composite resin with filler volume yields a positive correlation. The sonic-activated bulk-fill composite resin had the highest microhardness value and the largest filler volume, namely, 83.5 wt%/83 vol%. In contrast, high-viscosity and low-viscosity bulk-fill composite resins had the number of fillers 80 wt%/57 vol % and 70.5 wt%/47.4 vol%.
The viscosity of the composite also correlates with the type of resin matrix. Bis-GMA, as the thickest, is also the least flexible, while UDMA and TEGD-MA are the least viscous. The values of microhardness or VHN in this study [Table 1] are sorted from the highest to the lowest values. Furthermore, correlated with the type of matrix, namely, (1) sonic-activated high-viscosity bulk-fill composite resin with EBPADMA, (2) high-viscosity bulk-fill composite resin with UDMA and Bis-GMA, and (3) low-viscosity bulk-fill composite resin with TEGDMA.
Biochar (BC) supported nanoscale zerovalent iron (nZVI) composite was synthesized and used as an activator for persulfate to enhance the trichloroethylene (TCE) removal in aqueous solutions. The degradation efficiency of TCE (0.15mmolL(-1)) was 99.4% in the presence of nZVI/BC (4.5mmolL(-1), nZVI to BC mass ratio was 1:5) and persulfate (4.5mmolL(-1)) within 5min, which was significantly higher than that (56.6%) in nZVI-persulfate system under the same conditions. Owing to large specific surface area and oxygen-containing functional groups of BC, nZVI/BC enhanced the SO4(-) generation and accelerated TCE degradation. On the basis of the characterization and analysis data, possible activation mechanisms of the Fe(2+)/Fe(3+) (Fe(II)/Fe(III)) redox action and the electron-transfer mediator of the BC oxygen functional groups promoting the generation of SO4(-) in nZVI/BC-persulfate system were clarified.
Company X creates a job definition for the queryInventory composite that queries their inventory. The composite includes a synchronous BPEL process and a web service as the service binding component. You associate request-specific metadata as job definitions.
Oracle Enterprise Scheduler also enables you to schedule adapters in composites to be activated and deactivated at specified times. You can schedule to activate an adapter during periods when load on the system is minimal. The fulfillment composite designed in Fulfilling Orders includes a database adapter as a service input.
Company X uses Oracle Enterprise Scheduler to activate and deactivate the database adapter using recurring schedules. Company X selects Job Requests > Define Schedules from the Scheduling Services list. Company X configures activation and deactivation job definitions for the database adapter with the details shown in Table 8-2. The database adapter is configured to active every ten minutes, and then deactivate every ten minutes.
In order to consume the Yellow River sediment as much as possible and improve the longterm stability of the Yellow River, Yellow River sediment was utilized as the main raw material to produce a composite material. Ca(OH)2 was used as alkali-activator to activate the active SiO2 and Al2O3 compositions in Yellow River sediment. 10 wt% slag was added into the mixture to further improve the strength of the composites. The effect of activity rate of the Yellow River sediment and dosage of Ca(OH)2 on the compressive strength of the Yellow River sediment-slag composite material at different curing ages was researched. XRD, SEM/ EDS, light microscope and FTIR were used to further explore the products and the microstructure of the composite material. Results showed that the active ratio of sediment had a great influence on the compressive strength of specimen. In addition, the compressive strength of specimen increased with the increase of Ca(OH)2 dosage and curing age. When the dosage of Ca(OH)2 was more than 5 wt% as well as the curing age reached 90 days, the compressive strength of the composite material could meet the engineering requirement. In the alkali-activated process, the main product was hydrated calcium silicate (C-S-H) gel, which filled up the gaps among the sediment particles and decreased the porosity of the specimen. Moreover, the CaCO3 produced by the carbonization of the C-S-H gel and excess Ca(OH)2 also played a role on the strength.
Deformed REGULATION Protein Interactions Hox proteins are transcription factors that assign positional identities along the body axis of animalembryos. Different Hox proteins have similar DNA-binding functions in vitro and require cofactors toachieve their biological functions. Cofactors can function by enhancement of the DNA-bindingspecificity of Hox proteins, as has been shown for Extradenticle (Exd). Three results support anovel mechanism for Hox cofactor function. (1) The Hox protein Deformed (Dfd) can interact with simple DNA-binding sites inDrosophila embryos in the absence of Exd, but this binding is not sufficient for transcriptionalactivation of reporter genes. (2) Either Dfd or a Dfd-VP16 hybrid (VP16 is a transcriptional activation domain) mediate much strongeractivation in embryos on a Dfd-Exd composite site than on a simple Dfd-binding site, even though thetwo sites possess similar Dfd-binding affinities. This suggests that Exd is required to release thetranscriptional activation function of Dfd independent of Exd enhancement of Dfd-binding affinity onthe composite site. (3) Transfection assays confirm that Dfd possesses an activation domain,which is suppressed in a manner dependent on the presence of the homeodomain. The regulation ofHox transcriptional activation functions may underlie the different functional specificities of proteinsbelonging to this developmental patterning family (Li, 1999a). The neutral state of Dfd on simple binding sites indicates that additional regulatory steps and regulatorysequences are required for Dfd to activate gene expression. To test the hypothesis that Dfdbinding per se is inherently neutral in embryos, a test was performed to see whether high levels of Dfd orDfd-VP16 proteins could activate transcription through simple Dfd recognition sites. In vitro, a DNAsequence consisting of two tandem copies of the simple Deformed binding site (D site or 2D), is bound by Dfd with highaffinity but not detectably bound by Exd. The affinity of Dfd protein forthe 2D-site is not enhanced by the inclusion of Exd protein (Li, 1999a). A test was performed of the embryonic function a varient of the D site reporter construct. This varient contains two tandem copiesof a core sequence, to which Dfd and Exd bind together (2ED2 sites). In vitro, the 2ED2 site is bound weaklyby Dfd protein alone, but is not bound detectably by Exd alone. Binding of Dfdto the 2ED2 site is enhanced in the presence of Exd as shown by the formation of an abundantcomplex that contains Dfd, Exd and 2ED2. The affinity of theDfd-Exd heterodimer for the 2ED2 site is approximately the same as the affinity of the Dfd proteinalone for the 2D site. Although the 2D site and the2ED2 site have very similar in vitro affinity for Dfd in the presence of Exd, the2ED2 site is much more responsive than the 2D site to either Dfd or Dfd-VP16 proteins in embryos. This strongly suggests that Exd is required to release the transcriptional activation functionof Dfd in a way that is independent of the Exd enhancement of Dfd binding affinity on the 2ED2 site.At present, the most widely accepted models propose Exd as a cofactor that has its effect on Hoxspecificity by acting to increase the binding affinity of different Hox proteins to different compositebinding sites. The results presented here indicate that Exd has other regulatory effects on Hox proteins that may play arole in the diversification of function within the Hox family (Li, 1999a). Dfd protein contains an autonomous activation domain that is functional in transfection assays whenseparated from the C-terminal half of the protein. Ontandem repeats of simple Dfd-binding sites, the function of the Dfd transcription activation domain issuppressed both in cultured cells and in embryos. In embryos, this suppression can be partially relievedby the addition of Exd-binding sites to simple Dfd-binding sites. This is apparently due to the function ofthe Exd protein, since exd genetic function is required for the relief of the suppression of Dfd activationfunction on 2ED2 sites. In cultured cells, the suppression of Dfd activation function can be conferredby the homeodomain regions from either Dfd or Ubx. Since no evidence is found that there is a directintramolecular interaction between the Dfd homeodomain and its transcriptional activation region, a model is proposed that invokes a masking factor that suppresses the function of the activationdomain by contacting the homeodomain region. In addition, it is speculated that Exd may be required toalleviate the suppressive effect of the proposed masking factor by competing for overlappingprotein-protein interaction sites on the homeodomain (Li, 1999a). DFD and UBX bind to DNA with the recognition helix in the majorgroove 3' to the TAAT core sequence and the N-terminal arm in the adjacent minor groove.The N-terminal arm of a homeodomain iscapable of distinguishing an A.T base-pair from T.A in the minor groove. Specific orientation of theN-terminal arm within the binding site appears to vary between the homeodomains and influencesthe interaction of the recognition helix with the major groove (Draganescu, 1995). The DNA sequence preferences of homeodomains encoded by four of the eight Drosophila HOM proteins were compared. One of the four, Abdominal-B, binds preferentially to a sequence with an unusual 5'-T-T-A-T-3' core, whereas the other three prefer 5'-T-A-A-T-3'. Of these latter three, the Ultrabithorax and Antennapediahomeodomains display indistinguishable preferences outside the core while Deformed differs. Thus, with three distinct binding classes defined by four HOM proteins, differences in individual site recognition may account for some but not all of HOM protein functional specificity (Ekker, 1994).Specific amino acid residues at the amino end of theUltrabithorax homeodomain are required to specifically regulate Antennapedia transcription: inthe context of a Deformed protein, these amino-end residues are sufficient to switch fromDeformed- to Ultrabithorax-like targeting specificity. Although residues in the amino end of thehomeodomain are also important in determining a Deformed-like targeting specificity, other regionsof the Deformed homeodomain are also required for full activity (Lin, 1992).Deformed possesses an acidic region just N-terminal to the homeodomain and a C-terminal sequence called the C-tail region, containing poly-glutamine and poly-asparagine tracts. Removal of the acidic domain and the C-tail region converts a chimeric Deformed/Abdominal-B protein, possessing the Abdominal-B homeodomain, from a strong activator to a repressor of a Distal-less promoter element, but has little effect on activation of an empty spiracles element. Constructs without a third domain, the N-terminal N domain, fail to show any regulatory activity. These results suggest transcriptional activation by the N domain can be modulated by acidic and C-tail domains (Zhu, 1996).A heat-shock promoter/selector gene was constructed that encodes a Deformed/Abdominal-Bchimera in which the Abdominal-B homeodomain is substituted for that of Deformed. Expression ofthis chimeric protein throughout the embryo causes morphological transformation of anteriorsegments toward more posterior identities. A number of other homeotic selector genes, all normallyrepressed by Abdominal-B, are ectopically activated by the chimeric protein. These results supportthe hypothesis that the target specificity of similar homeodomain proteins is largely determined bythe amino acid sequence of the homeodomain (Kuziora, 1990). The relevance of functional interactions between Prospero andhomeodomain proteins is supported by the observation that Prospero, together with the homeodomainprotein Deformed, is required for proper regulation of a Deformed-dependent neural-specifictranscriptional enhancer. Deformed and mouse Hoxa-5 binding to this neuronal enhancer is increased more than 10 fold by Pros. Pros reduces Eve's DNA binding to this enhancer, but does not modulate the binding of Engrailed. This interaction is unidirectional and specific, since neither Dfd, Eve nor En has an effect on Pros binding. The modulation by Pros does not require Pros binding to DNA. Pros protein modifies the trypsin sensitivity of Dfd protein, suggesting that Pros binds Dfd and is able to induce a conformation change in Dfd. Nevertheless, Pros is able to bind the Dfd neuronal autoregulatory enhancer and enhances Dfd binding to this DNA sequence. The DNA-binding and homeodomain protein-interactingactivities of Prospero are localized to its highly conserved C-terminal region, and the tworegulatory capacities are independent (Hassan, 1997). Hox transcription factors, in combination with cofactorssuch as Exd protein and itsmammalian Pbx homologs (PBC proteins), provide diverse developmental fatesto cells on the anteroposterior body axis of animal embryos.However, the mechanisms by which the different Hoxproteins and their cofactors generate those diverse fatesremain unclear. Recent findings have provided support fora model where the DNA binding sites that directly interactwith Hox-PBC heterodimers determine which member ofthe Hox protein family occupies and thereby regulates agiven target element. In the experiments reported here, the function of chimeric Hox response elements is tested, and,surprisingly, evidence is found that runs counter to this view. A21 bp cofactor binding sequence from an embryonicDeformed Hox response element (region 6), containing no Hox orHox-PBC binding sites, was combined with single ormultimeric sites that binds heterodimers of Labial-type Hoxand PBC proteins (region 3). Normally, multimerized Labial-PBCbinding sites are sufficient to trigger a Labial-specificactivation response in either Drosophila or mouse embryos.The 21 bp sequence element plays animportant role in Deformed specificity, because it is capable ofswitching a Labial-PBC binding site/response element to aDeformed response element. Thus, cofactor binding sitesthat are separate and distinct from homeodomain bindingsites can dictate the regulatory specificity of a Hox responseelement (Li, 1999b).The instructive role of factors bound to non-Hox bindingsites in controlling Hox responses is probably a generalmechanism by which different Hox proteins acquire distinctfunctions. Exd is a well-characterized example that is used ina subset of Hox-activated response elements. However, theinfluence of Exd on Hox specificity may be superseded incomplex elements that contain sequences such as region 6.How the specificity code is generated in the average Dfd orUbx response element is likely to vary depending on the celltype, the presence or absence of Exd in the cell, the stage ofdevelopment, and the extracellular signals that are received bya given response element. The putative activating cofactorbinding site(s) (GGC..AAAGC) in the region 6 element arepresent in other naturally derived Dfd response elements, so there may be an important subset of Dfd responseelements that rely on these sites for maxillary specificity. Atpresent, none of the known complex elements that respond toother Hox proteins contain good matches to the GGC..AAAGC motifs. The region6 cofactor(s)