Highest TP Research Articles

The effect of aging on the translucency of contemporary zirconia generations: in-vitro study

BackgroundThe translucency of different zirconia generations at each time point after thermocycling aging is still lacking.MethodsFour zirconia materials were used with a total of 60 samples produced from monolithic third generation (5Y) 5 mol% yttria-stabilized zirconia polycrystalline ceramic and fourth generation zirconia (4Y) 4 mol% yttria-stabilized zirconia polycrystalline ceramic, represented by [group1:[CM-5Y] Ceramill Zolid fx (3rd generation zirconia) (Amann Girrbach, Koblach, Austria), group 2:[CM-4Y] Ceramill Zolid HT + (4th generation zirconia) (Amann Girrbach, Koblach, Austria), group 3:[CC-5Y] Cercon XT/ML (Dentsply Sirona, Germany) (3rd generation), and group 4:[CC-4Y] Cercon HT/ML (Dentsply Sirona, Germany) (4th generation)]. The L*a*b* figures were measured by using a spectrophotometer at baseline and after 10,000, 30,000, and 50,000 cycles of thermocycling. At each interval, the translucency of the samples was estimated by using the translucency formula CIEDE2000. The Scheffe post-hoc compared differences among each of the four materials. The Repeated measures ANOVA tested the differences between the materials at each of the different thermocycling intervals (p < .001). Data analyses were evaluated at a significance level of p < .05 (CI 95%).ResultsTwo-way ANOVA revealed that at baseline the third and fourth generation’s zirconia showed statistically significant differences in translucency (P < .001). Translucency values at baseline and after thermocycling exhibited statistically significant changes (p = .003). At each of the time interval; CM-4Y had the highest translucency values followed by CM-5Y, CC-4Y and CC-5Y had the least translucency values.ConclusionsThe third and fourth generations of zirconia displayed different translucencies. Thermocycling affected the translucency of both third and fourth generations of zirconia. At each of the time intervals group 2:[CM-4Y] had the highest TP followed by group1:[CM-5Y], while, group 3:[CC-5Y] and group 4:[CC-4Y] had the least TP.

Community characteristics of phytoplankton and eutrophication assessment in Tianjin section, downstream of Haihe River Basin

With the aim of exploring the features of the phytoplankton community and eutrophication status in the lower reaches of the Haihe River Basin near Tianjin, sampling surveys were carried out in May, July and September of 2021. The results showed 53 dominant phytoplankton species in the survey area, of which 36 species were found in May, while 28 were found both in July and September. Ten dominant species were highlighted in the surveys, mainly belonging to Cyanophyta, Chlorophyta, Bacillariophyta, and Cryptophyta. The regions with relatively higher levels of phytoplankton biomass and abundance were Duliujian River, Qilihai Wetland and New Chaobai River, while the highest species richness and biodiversity occurred in Yuqiao Reservoir, Duliujian River, New Chaobai River and Ji Canal. The highest TN content was observed in Duliujian River, and the highest TP, chl-a, CODMn and EI were recorded in New Chaobai River. In contrast, the region with the lowest level of eutrophication was Yuqiao Reservoir. Correlation analysis and RDA analysis showed that the eutrophication assessment indices affecting the phytoplankton community and distribution of dominant species were mainly TN, chl-a and CODMn in May and July, while TN, TP, chl-a, CODMn and EI were the most influential in September.

Optical properties of CAD-CAM monolithic systems compared: three multi-layered zirconia and one lithium disilicate system

Objectivethis in vitro investigation aims to evaluate and compare optical properties of three types of esthetic CAD-CAM monolithic multi-layered zirconia materials with a control (conventional lithium disilicate, IPS e. max CAD). MethodsFour monolithic CAD-CAM ceramic materials were investigated: Ceramill Zolid® FX Multilayer (ZF), IPS e. max® ZirCAD MT Multi (ZM), Katana® STML (KS) and one lithium disilicate glass-ceramics as a control (IPS e. max® CAD LT; LC). A total of 72 (15 × 15 × 1 mm) samples were CAD CAM fabricated and sintered based on sample-size power calculations, and each material comprised 18 samples. The translucency and opalescence parameters with the contrast ratio were evaluated with a dental spectrophotometer over the backgrounds of black and white. The data were analyzed by ANOVA, then Bonferroni post hoc comparison test was made between groups. The statistical significance was set at p < 0.05. ResultsZirconia materials revealed lower optical properties than the lithium disilicate control LC (P < 0.05). TP values ranged from 14.174 to 20.439. No differences were detected between the zirconia products in terms of TP and CR (P = 1.000). OP values ranged from 5.068 to 10.097. The lowest OP values were found statistically significant for ZF followed by KS and ZM (P = 1.000). LC had the highest TP and OP values, as well as the lowest CR (p < 0.05). ConclusionsThe optical properties of monolithic zirconia systems tested here are still lower than those of lithium disilicate glass-ceramics. The only difference observed between the monolithic CAD CAM zirconia materials, was for the low opalescence parameter for the ZF. Clinical significanceMulti-layered monolithic zirconia systems have better esthetics by shade layers resembling natural tooth color gradients. CAD-CAM technology allowed for in-office milling and shaping of restorations using these systems. This study reports on their optical properties affecting human vision/perception of natural tooth shade to conclude about their use in the esthetic zones.

Performance of citrus charcoal and olivepomace charcoal as natural substrates in the treatment of municipal wastewater by vertical flow subsurface constructed wetlands

This research investigated two pilot scale vertical flow constructed wetlands systems (VFCWs) with alternative substrates (olivepomace charcoal and citrus charcoal) for removing inorganic pollutants, organic, and pathogens from municipal wastewater of secondary treatment. Each system design consists of two stages, the first one included olivepomace charcoal, while the second design included olivepomace charcoal with citrus charcoal. The system configurations were optimized and operated under different hydraulic retention time HRT (12-24-36-48-96-144-192 h).The results of tests revealed that the optimal removal efficiency for COD, BOD, TKN and Fecal Coliform obtained in system2 (98%, 98%, 71% and 99% at192 h), respectively. The highest TP and TSS removal was observed in the system1 (80% and 97% at 192 h), respectively. The pollutants (COD, BOD, TKN and Fecal Coliform) adsorption capacity of citrus charcoal is faster than citrus charcoal with olivepomace charcoal. However, olivepomace charcoal achieved better removal efficiency with an increase HRT. Overall, citrus charcoal and olivepomace charcoal proved to be efficient alternative substrates in CWs.

Anti-Inflammatory, Antioxidant and Enzyme Inhibition Activities in Correlation with Mycochemical Profile of Selected Indigenous Ganoderma spp. from Balkan Region (Serbia).

The aim of this research work was to study the bioactivity potentials (antioxidant, anti-inflammatory, and enzyme inhibitory) of ethanol (EtOH), water (H2 O) and chloroform (CHCl3 ) extracts of G. applanatum, G. lucidum, G. pfeifferi and G. resinaceum as well as their mycochemical profile: the total content of phenolics (TP) and sugars (TS) and LC/MS/MS detection of phenolics. LC/MS/MS profile showed that p-hydroxybenzoic and protocatechuic acids were mostly found. The highest ABTS and DPPH activities were detected in polar G. applanatum extracts (159.84±0.59 mg TE/g d.w., IC50 =0.85±0.30 μg/mL, respectively), while G. resinaceum CHCl3 extract was the most potent in NO assay (IC50 =41.21±0.18-81.89±0.81 μg/mL). The highest TP and TS were generally determined in G. applanatum EtOH extracts. Enzyme inhibitory effects were determined in H2 O extracts. Generally, CHCl3 extracts showed the most powerful anti-inflammatory potential. These results suggest that analyzed species are a promising source of bioactive compounds and may be considered as candidates for new food supplements or drug formulations.

The interplay between superconductivity and non-Fermi liquid at a quantum-critical point in a metal

Near a quantum-critical point, a metal reveals two competing tendencies: destruction of fermionic coherence and attraction in one or more pairing channels. We analyze the competition within Eliashberg theory for a class of quantum-critical models with an effective dynamical electron–electron interaction V(Ωm)∝1∕|Ωm|γ (the γ-model) for 0<γ<1. We argue that the two tendencies are comparable in strength, yet the one towards pairing is stronger, and the ground state is a superconductor. We show, however, that there exist two distinct regimes of system behavior below the onset temperature of the pairing Tp. In the range Tcross<T<Tp fermions remain incoherent and the spectral function A(k,ω) and the density of states N(ω) both display “gap filling” behavior in which, i.e., the position of the maximum in N(ω) is set by temperature rather than the pairing gap. At lower T<Tcross, fermions acquire coherence, and A(k,ω) and N(ω) display conventional ”gap closing” behavior, when the peak position in N(ω) scales with the gap and shifts to a smaller value as T increases. We argue that the existence of the two regimes comes about because of special behavior of fermions with frequencies ω=±πT along the Matsubara axis. Specifically, for these fermions, the component of the self-energy, which competes with the pairing, vanishes in the normal state. We further argue that the crossover at T∼Tcross comes about because Eliashberg equations allow an infinite number of topologically distinct solutions for the onset temperature of the pairing within the same gap symmetry. Only one solution, with the highest Tp, actually emerges, but other solutions are generated and modify the form of the gap function at T≤Tcross. Finally, we argue that the actual Tc is comparable to Tcross, while at Tcross<T<Tp phase fluctuations destroy superconducting long-range order, and the system displays a pseudogap behavior.

Microstructural, physical, and optical characterization of high-translucency zirconia ceramics

Statement of problemThe microstructural, physical, and optical properties of newly available highly-translucent zirconia ceramics have not been thoroughly investigated. PurposeThe purpose of this in vitro study was to evaluate the microstructural, physical, and optical properties of current zirconia ceramics with different degrees of translucency and to compare the optical properties with lithium disilicate glass-ceramic at different thicknesses. Material and methodsDisk-shaped specimens (N=108) were prepared from 3 different monolithic zirconia ceramics: VITA YZ HT (YZ-HT), VITA YZ ST (YZ-ST), and VITA YZ XT (YZ-XT) and lithium disilicate glass-ceramic (IPS e-max CAD LT [IPS]) with a diameter of 14 mm and 3 different thicknesses (0.5, 1.0, and 1.5 mm ±0.02 mm). The microstructural features (grain size, elemental composition, phase identifications, and quantifications), physical properties (Vickers hardness and fracture toughness), and optical properties (translucency parameter and contrast ratio) were investigated. Data were analyzed using 1-way ANOVA, followed by the post hoc Tukey tests or Kruskal-Wallis and Mann-Whitney U tests (α=.05). ResultsDifferences in grain size, phase assemblages, fracture toughness, translucency parameter, and contrast ratio were found to be significant (P<.05). The average grain size was different for the 3 zirconia specimens with the following order: YZ-XT>YZ-ST>YZ-HT. The fracture toughness of YZ-HT was higher than that of YZ-ST and YZ-XT (P<.05). IPS with 0.5-mm thickness had the highest TP followed by YZ-XT and YZ-ST. The CR values were in the range of 0.54 to 0.91 (YZ-HT), 0.43 to 0.61 (YZ-ST), 0.29 to 0.45 (YZ-XT), and 0.27 to 0.53 (IPS), and all decreased with an increase in thickness. ConclusionsBased on the results of the present study, the microstructural, physical, and optical properties of zirconia ceramics were affected by the changes in chemical composition and sintering parameters.

Masking ability of indirect restorative systems on tooth-colored resin substrates

ObjectiveTo evaluate the masking ability of different indirect restorative systems (IRS) on tooth-colored resin substrates. MethodsA1-shaded specimens from 5 IRS (LDC–IPS e.max® CAD; YZW-Zenostar Zr Translucent; PICN-Enamic; YLD-T-IPS e.max® ZirCAD + IPS e.max Ceram; CAD-on-Zenostar Zr Translucent + Crystall./Connect + IPS e.max® CAD) were fabricated. Specimens (n = 5) were cemented with a resin luting agent (Variolink® N; shade White) on three different shades (ND3, ND8 and ND9) of a tooth-colored resin substrate (IPS Natural Die Material). Spectral reflectance and color coordinates were measured using a spectroradiometer under standardized lighting conditions (CIE D65 illumination) and optical geometry 0/45°. Color differences (ΔEab* and ΔE00) from cemented specimens and CIELAB- and CIEDE2000-based translucency parameter (TP and TP00) from non-cemented specimens were calculated. Data was statistically analyzed using one-way ANOVA and Tukey’s tests (α = 0.05). ΔE values were also analyzed using perceptibility (PT = 1.22 ΔEab* units; 0.81 ΔE00 units) and acceptability (AT = 2.66 ΔEab* units; 1.77 ΔE00 units) thresholds. ResultsThe cemented specimens of CAD-on, LDC, YZW and PICN on different substrates (ND3–ND8, ND3–ND9 and ND8–ND9) showed different ΔEab* and ΔE00 values (p ≤ 0.05), which were above AT. YLD-T showed ΔEab* and ΔE00 values below AT for all comparisons. Lowest and highest TP and TP00 values were obtained for YLD-T and PICN, respectively (p ≤ 0.05). SignificanceResin-cemented YLD-T on different tooth-colored substrates showed less translucency as well as smaller color differences (below acceptability threshold), indicating the best masking ability among evaluated systems.

Phenolic composition and total antioxidant capacity of South African frozen concentrated orange juice as affected by varietal, seasonal and regional differences.

There is epidemiological evidence that fruits and vegetables promote general health due to their phenolic composition. The phenolic composition of three commercially important citrus varieties ('Mandarin', 'Navel' orange and 'Valencia' orange), used for frozen concentrated orange juice (FCOJ) production in South Africa, were evaluated based on variety, production season and geographical region (Western Cape (WC) and Eastern Cape (EC)). FCOJ from the WC had significantly (P < 0.05) lower titratable acidity (TA) and higher total soluble solids (TSS):TA ratio compared to FCOJ produced in the EC. The 'Navel' FCOJ, irrespective of season and region, had the highest (P < 0.05) phenolic content (sum of quantified compounds, TP). Regional effects were clear for the 'Mandarin' variety, the EC 'Mandarin' FCOJ had the highest TP and WC 'Mandarin' had the lowest. Seasonal differences were less evident. Variation that could be ascribed to regional differences were also found for individual phenolic compounds. Robust data regarding the phenolic profile of FCOJ produced in South Africa, suitable for inclusion in food composition databases, were collected. © 2018 Society of Chemical Industry.

Reconstructing the Trophic History of an Alpine Lake (High Tatra Mts.) Using Subfossil Diatoms: Disentangling the Effects of Climate and Human Influence

Diatom analysis was undertaken on a 200-year sediment record in an alpine lake (Popradské pleso, Tatra Mountains, Central Europe). Due to its remote character and well-documented human influence since the mid-nineteenth century, it allows a study of the relationship between anthropogenic pressures and diatom assemblages. Altogether, 122 diatom taxa of 40 genera were identified, and two major taxonomic shifts were revealed in the stratigraphic record. The timing of the first significant shift in ~ 1850 precludes the possibility of being caused by direct human activities, since according to historic documents there was neither continuous human presence nor grazing in the valley before that time. In addition, the direct effect of organic pollution early in the 1960s connected with the operation of a tourist hotel was not clearly reflected in the diatom signal. The diatom-inferred total phosphorus (DI-TP) reconstruction indicated the highest TP content well before the most direct wastewater pollution from a newly built hotel. There was a considerable effect of climate to diatom assemblage structure as well as diatom life forms. Our results suggest that direct organic pollution influenced the diatom communities less than expected, and the main driver of change was climate warming. We hypothesize that it is because of the short residence time of the lake, since it has both strong inlet and outlet, and it has been showed that the inlet had significant effect on benthic communities in the past. At the same time, fish manipulation could have been the reason for some fluctuation in DI-TP unrelated to climate and organic pollution.

A hybrid land-water-environment model for identification of ecological effect and risk under uncertain meteorological precipitation in an agroforestry ecosystem

In this study, a hybrid land-water-environment (LWE) model is developed for identifying ecological effect and risk under uncertain precipitation in an agroforestry ecosystem. A simulation-based fuzzy-stochastic programming with risk analysis (SFSR) method is used into LWE model to reflect the meteorological impacts; meanwhile, it also can quantify artificial fuzziness (e.g., risk attitude of policymaker) and natural vagueness (e.g., ecological function) in decision-making. The developed LWE model with SFSR method is applied to a practical agroforestry ecosystem in China. Results of optimized planting scale, irrigative water schedule, pollution mitigation scheme, and system benefit under changed rainfall, precise risk-adoption and vague ecological function are obtained; meanwhile their corresponding ecological effects and risks are analyzed. It found that current LWE plans could generate massive water deficits (e.g., 23.22×106m3 in crop irrigation and 26.32×106m3 in forest protection at highest) due to over-cultivation and excessive pollution discharges (e.g., the highest excessive TP and TN discharges would reach 460.64 and 15.30×103 ton) due to irrational fertilization, which would increase regional ecological risks. In addition, fifteen scenarios associated with withdrawing cultivation and recovering forest based on regional environment heterogeneity (such as soil types) have been discussed to adjust current agriculture-environment policies. It found that, the excessive pollution discharges (TN and TP) could be reduced 12.95% and 18.32% at highest through ecological expansions, which would generate higher system benefits than that without withdrawing farmland and recovering forest. All above can facilitate local policymakers to modulate a comprehensive LWE with more sustainable and robust manners, achieving regional harmony between socio-economy and eco-environment.

Microstructural evolution and characterisation of interfacial phases in Al2O3/Ag–Cu–Ti/Al2O3 braze joints

Alumina ceramics with different levels of purity have been joined to themselves using an active braze alloy (ABA) Ag–35.3Cu–1.8Tiwt.% and brazing cycles that peak at temperatures between 815°C and 875°C for 2 to 300min. The microstructures of the joints have been studied using scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray spectroscopy. A limited number of joints prepared with the ABA Ag–26.7Cu–4.5Tiwt.% have also been studied. In terms of characterising the interfacial phases, efforts were made to understand the interfacial reactions, and to determine the influence of various brazing parameters, such as the peak temperature (Tp) and time at Tp (τ), on the microstructure. In addition, the extent to which impurities in the alumina affect the interfacial microstructure has been determined.Ti3Cu3O has been identified as the main product of the reactions at the ABA/alumina interfaces. At the shortest joining time used, this phase was observed in the form of a micron-size continuous layer in contact with the ABA, alongside a nanometre-size layer on the alumina that was mostly composed of γ-TiO grains. Occasionally, single grains of Ti3O2 were observed in the thin layer on alumina. In the joints prepared with Ag–35.3Cu–1.8Tiwt.%, the interfacial structure evolved considerably with joining time, eventually leading to a high degree of inhomogeneity across the length of the joint at the highest Tp. The level of purity of alumina was not found to affect the overall interfacial microstructure, which is attributed to the formation of various solid solutions. It is suggested that Ti3Cu3O forms initially on the alumina. Diffusion of Ti occurs subsequently to form titanium oxide at the Ti3Cu3O/alumina interface.

Influence of the electrohydrodynamic process on the properties of dried button mushroom slices: A differential scanning calorimetry (DSC) study

In this paper, drying of button mushroom (Agaricus bisporus) slices with an innovative drying technique of hot air combined with Electrohydrodynamic (EHD) drying process was investigated at three electrode gaps (5, 6, and 7cm) and voltage levels (17, 19, and 21kV). The effects of different hot air combined with EHD drying treatments on the temperature of the mushroom slices, drying time, final color and protein denaturation features including enthalpy (ΔH), onset temperature (To), peak transition temperature (Tp), conclusion temperature (Tc), and temperature range (Tc–To) of endothermic peaks were systematically evaluated. In addition, water state changes in DSC cooling thermograms of dried mushroom slices were investigated. The results obtained by differential scanning calorimetry showed that the ΔH values in the DSC traces of the EHD-dried mushroom slices were reduced with a decrease in the electrode gap and an increase in the voltage. Specifically, among voltages of 21, 17, and 19kV, a voltage of 21kV resulted in the lowest ΔH and Tc–To values and the highest Tp and To values. This result indicated that voltage had a significant effect on these responses. Similarly, the DSC results showed a considerable effect of high electric field intensity on ΔH, Tc–To and Tp responses related to protein denaturation in comparison to low electric field intensity.

Co-solvent Selection for Supercritical Fluid Extraction of Essential Oil and Bioactive Compounds from Polygonum minus

This study evaluated the biological activity (antioxidant assay) of Polygonum minus extracted using Supercritical Fluid Extraction (SFE) added with different types of co-solvents. The seven co-solvents employed were water, methanol, ethanol, 50% methanol, 50% ethanol, 70% methanol and 70% ethanol for selection of the best co-solvent prior to optimization of SFE. 70% methanol produced the highest total yield of extract (33.1%) compared to other co-solvents. The antioxidant capacity was then evaluated using four different assays: the total phenolic content (TP), the total flavonoid content (TF), the ferric reducing/antioxidant power (FRAP) and the free radical-scavenging capacity of 2,2-diphenyl-1-picrylhydrazyl (DPPH). The highest TP and TF were from 70% methanol extract (11.2 ± 0.15 mg GAE/g sample (mg GAE/g) and 11.9 ± 0.03 mg CAE/g sample (mg CEQ/g) respectively). 70% metanol extract also showed the highest FRAP value (346.7 ± 0.66 µmol Fe (II)/g sample) and the highest percentage of DPPH radical inhibition was also shown by 70% methanol extract (88.7 ± 0.40%). There was a positive correlation between the antioxidant capacity (FRAP and DPPH) with those of TP and TF contents. Therefore, the best co-solvent chosen for further optimization of SFE is 70% methanol.

Effect of Placement Pattern and Quantity of Iron Shavings in Reactor on Biological Nutrient Removal from Domestic Wastewater

Effect of placement pattern and quantity of iron shavings in reactor on biological nutrient Removal from domestic wastewater was conducted. The results indicate that: different placement pattern had obvious effect on TP removal, but had no distinct effect on TN removal; when iron was placed beside aerator, the highest TP removal can be obtained. Adding more iron can just slightly enhance TP and TN removal when iron shaving quantity increased from 5 g to 20 g per 900 ml wastewater; iron adding restrained transfer of ammonia to nitrate by microbe and this defect should be overcome in practice; 5 g iron per 900 mL is the best choice to balance good nutrient removal and low cost.

Involvement of Carbohydrate, Protein and Phenylanine Ammonia Lyase in Up-Regulation of Secondary Metabolites in Labisia pumila under Various CO2 and N2 Level

A split plot factorial 2 × 3 experiment was designed to examine and characterize the relationships among secondary metabolites (total phenolics, TP; total flavonoids, TF), carbohydrate content, C/N ratio, protein synthesis and L–phenylalanine ammonia lyase (PAL; EC 4.3.1.5) activity in the Malaysian medicinal herb Labisia pumila (Blume) Fern-Vill. under different CO2 concentrations (400 = ambient and 1,200 µmol mol−1 CO2) and three levels of nitrogen fertilization (0, 90 and 270 kg N ha−1) for 15 weeks. The interaction between CO2 and nitrogen levels imposed a significant impact on plant secondary metabolite production, protein, PAL activity and fructose levels. Highest TP and TF were recorded under 1,200 µmol mol−1 CO2 when N fertilizer was not applied; lowest values were obtained at 400 µmol mol−1 CO2 fertilized with the highest N level. Concurrently, fructose contents increased tremendously. Increase in fructose content might also enhance erythose-4-phosphate production (substrate for lignin and phenolic compounds), which shares a common precursor transdalolase in the pentose phosphate pathway. PAL activity was noted to be highest under 1,200 µmol mol−1 CO2 + 0 kg N ha−1 coinciding with subsequent recording of the lowest protein content. The results implied that the increase in plant secondary metabolites production under the tested conditions might be due to diversion of phenylalanine for protein synthesis to production of secondary metabolites. It was also found that the sucrose to starch ratio was also high under high levels of nitrogen fertilization, indicating an enhanced sucrose phosphate synthase activity (SPS; EC 2.4.1.14) under such condition.

Suppression of thymidine phosphorylase expression by promoter methylation in human cancer cells lacking enzyme activity

Thymidine phosphorylase (TP, EC 2.4.2.4) activity varies in different human cancer cell lines. Nevertheless, little is known about the regulatory mechanisms of TP expression in such cancers. Promoter methylation of dinucleotide cytosine-guanine (CpG) sites is a known mechanism of reversible gene expression silencing. TP promoter methylation was investigated in five cancer cell lines (SKBR-3, 786-O, HT-29, MDA-231, DLD-1). TP mRNA levels were determined by real-time quantitative PCR. The degree of methylation was identified by bisulfite sequencing. Minimal TP promoter activity was determined by Luciferase reporter assays. DNA-protein interactions were evaluated by electrophoretic mobility shift assays. SKBR-3 cells exhibited the highest TP expression, 786-O, HT-29, and MDA-231 cells exhibited intermediate TP expression, while DLD-1 cells did not express TP as demonstrated by TP mRNA, protein, and enzyme activity levels. SKBR-3 lacked methylation in the TP promoter, intron 1 and exon 1 regions, while DLD-1 showed extensive methylation. Treatment of DLD-1 and SKBR-3 with the methylation-inhibitor, 5-aza-2'-deoxycytidine (5-aza-2dC), resulted in a concentration-dependent increase in TP mRNA and protein levels in DLD-1 but not SKBR-3 cells. Trichostatin-A treatment, a histone deacetylase inhibitor, improved the 5-aza-2dC-induced TP re-activation. Electrophoretic mobility shift assays demonstrated that methylation significantly inhibits transcription factor binding. Supershift analyses suggest that the Sp1 and Sp3 (to a lesser degree) transcription factors have a role in the regulation of TP expression. These findings suggest that TP promoter methylation is a mechanism for down-regulation of TP expression in cancer cells and may have implications in modulating prognosis of cancer patients.

High Damping Performance of Hydrogenated Bulk Metallic Glasses

Hydrogenated Zr-Cu-base metallic glasses (MGs) are the potential high-damping and high-strength materials. On the other hand, the knowledge on the material parameters which govern the peak temperature, Tp, and the peak height, Q-1 p, of the hydrogen internal friction peak (HIFP) remains poor. In order to pursue this issue, the hydrogen concentration dependence of Tp and Q-1 p in the Zr-Cu-base MGs were investigated in the point of view of the hydrogen induced structural relaxation (HISR). It is found that the Tp vs. CH data and the Q-1 p vs. CH data are well fitted by the relationships of Tp = Tp exp(-CH/τH) +Tp,0 and Qp -1 ∝ ln(CH/τH), respectively, for various Zr-Cu-base MGs including bulk MGs, Zr55Cu30Al10Ni5 and Zr60Cu30Al10. That is, the observed relationship between Tp and CH is mainly governed by HISR. It is suggested that Tp,0 in Zr-Cu-base MGs is the highest among various MGs resulting in the highest Tp in Zr-Cu-base MGs. In other words, the control of Tp,0 is the key issue to find the high-Tp MGs.

Vector competence of South African Culicoides species for bluetongue virus serotype 1 (BTV-1) with special reference to the effect of temperature on the rate of virus replication in C. imicola and C. bolitinos.

The oral susceptibility of 22 South African livestock associated Culicoides species to infection with bluetongue virus serotype 1 (BTV-1) and its replication rate in C. imicola Kieffer and C. bolitinos Meiswinkel (Diptera: Ceratopogonidae) over a range of different incubation periods and temperatures are reported. Field-collected Culicoides were fed on sheep blood containing 7.5 log10TCID50/mL of BTV-1, and then held at constant different temperatures. Virus replication was measured over time by assaying individual flies in BHK-21 cells using a microtitration procedure. Regardless of the incubation temperatures (10, 15, 18, 23.5 and 30 degrees C) the mean virus titre/midge, infection rates (IR) and the proportion of infected females with transmission potential (TP = virus titre/midge > or = 3 log10 TCID50) were found to be significantly higher in C. bolitinos than in C. imicola. Results from days 4-10 post-infection (dpi), at 15-30 degrees C, shows that the mean IR and TP values in C. bolitinos ranged from 36.7 to 87.8%, and from 8.4 to 87.7%, respectively; in C. imicola the respective values were 11.0-13.7% and 0-46.8%. In both species the highest IR was recorded at 25 degrees C and the highest TP at 30 degrees C. The time required for the development of TP in C. bolitinos ranged from 2 dpi at 25 degrees C to 8 dpi at 15 degrees C. In C. imicola it ranged from 4 dpi at 30 degrees C to 10 dpi at 23.5 degrees C; no individuals with TP were detected at 15 degrees C. There was no evidence of virus replication in flies held at 10 degrees C. When, at various points of incubation, individual flies were transferred from 10 degrees C to 23.5 degrees C and then assayed 4-10 days later, virus was recovered from both species. The mean virus titres/midge, and proportion of individuals with TP and IR, were again significantly higher in C. bolitinos than in C. imicola. Also the infection prevalence in C. magnus Colaço was higher than in C. imicola. Low infection prevalences were found in C. bedfordi Ingram & Macfie, C. leucostictus Kieffer, C. pycnostictus Ingram & Macfie, C. gulbenkiani Caeiro and C. milnei Austen. BTV-1 was not detected in 14 other Culicoides species tested; however, some of these were tested in limited numbers. The present study indicates a multivector potential for BTV transmission in South Africa. In C. imicola and C. bolitinos the replication rates are distinct and are significantly influenced by temperature. These findings are discussed in relation to the epidemiology of bluetongue in South Africa.

Ferromagnetism at room temperature in La0.8Ca0.2MnO3 thin films

Anomalously high metal–insulator transition temperature Tp and ferromagnetic transition temperature Tc have been observed in thin films of La0.8Ca0.2MnO3. Ferromagnetic resonance signals from microwave studies are observed at room temperature (well above Tc) suggesting the presence of multiple magnetic spin systems. The Tp and Tc values are higher than that of La0.67Ca0.33MnO3 which have the highest Tp and Tc according to the bulk phase diagram. These results suggest that properties well beyond those seen in the bulk phase diagram may be achievable in thin films of the manganites.