Oviposition-Deterrent Effect of a High-Quality Natural Zeolite on the Olive Fruit Fly Bactrocera oleae, under Different Conditions of Temperature and Relative Humidity.

In recent years, the number of available chemical pesticides has been dramatically reduced, urging the need for the discovery of alternatives to chemical pesticide products such as, among others, natural zeolites (zeolitic rocks). We determined the mineralogical and chemical composition of a specific and continuous layer of zeolitic rock sample (ZeotP) from Petrota, Evros, Greece, and evaluated its oviposition-deterrent effect on the olive fruit fly Bactrocera oleae Gmelin (Diptera: Terphritidae). The tested natural zeolite contained 70 wt. % clinoptilolite, 18 wt. % amorphous material, 7 wt. % feldspars, 4 wt. % cristobalite, and 1 wt. % quartz. We tested the oviposition-deterrent effect of ZeotP mixed or not with an emulsifier adjuvant, NU-FILM-P®, in water and applied it to the surface of olive fruits. The ZeotP oviposition-deterrent effect on the olive fly was very high under a series of tested temperatures (17 °C, 20 °C, 25 °C, and 30 °C) and RHs (23%, 33%, 55%, 75%, and 94%). In addition, the ZeotP residual deterrent effect after equable water spraying was high, like the respective effect of the pyrethroid insecticide Decis® (deltamethrin). Our results may contribute to the effective control of the olive fruit fly using an alternative to chemical pesticides: natural zeolite (zeolitic rocks) products.

Effect of different zirconia surface pretreatments on the flexural strength of veneered Y-TZP ceramic before and after in vitro aging.

PURPOSE: The investigation of zirconia core surface pretreatments on the flexural strength of bilayered zirconia ceramics before and after artificial accelerating aging. METHODS: Ninety bar-shaped specimens were manufactured from Yttria Stabilized Tetragonal Zirconia Polycrystal (Y-TZP) and divided in three groups depending on zirconia surface pretreatment before veneering: layering with liner, pretreatment with silane-containing gas flame (SGF) with the Silano-Pen device and alumina air-abrasion. Half of the veneered specimens in each group (n=15) underwent artificial accelerating aging. A 4-point bending test was performed to determine flexural strength. Three specimens from each group were further analyzed using Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) before veneering and after fracture (aged and non-aged subgroups). RESULTS: Alumina air-abrasion was correlated to increased phase transformation from tetragonal to monoclinic zirconia phase. Qualitative analysis revealed that with the majority of the specimens pretreated with the silane-containing gas flame, areas of the veneering material remained firmly attached to the zirconia core after flexural strength testing. There was no statistically significant difference on the flexural strength among the groups before or after aging. Artificial accelerating aging resulted in statistically significant higher flexural strength of the specimens after aging. CONCLUSION: SGF pretreatment can be an acceptable and feasible alternative method before the veneering of Y-TZP zirconia as it presented slightly higher bond strength compared with alumina air-abrasion which was associated with higher tetragonal to monoclinic (t→m) phase transformation. Accelerating aging leads to an increase of the mechanical properties under in vitro conditions.

Natural radioactivity studies in a paleontology site and paleoclimate interpretation of the last 8 Mya.

Fossil bones and sediments from different horizons of the Upper Miocene paleontological site of Platania, Drama-Greece were studied using 238U, 235U, 232Th series and 40K measurements obtained by γ-spectroscopy. Additionally, SEM and XRF analysis was applied to bone and sediment samples while a lithological analysis of the sediments was also carried out. The 226Ra/238U ratios in the fossilization layers are attributed to the 238U depletion from the sediment and its incorporation into the fossils. The 226Ra/231Pa ratio indicates that the absorption of the isotopes started long before 4.2 Ma ago. The 232Th/40K profile demonstrate two distinct geological substrates, the lower corresponding to the Upper Miocene whereas the upper to the Upper Pleistocene-Holocene. Among them mediates a Mn-rich layer associated with the "Zanclean flood" during Pliocene. One layer above the "Glacial maximum event" during the Early Pleistocene was recorded. The natural radioactive sedimentary profile obtained reproduces the paleo-climatic conditions in Southeast Europe, which could be useful for the future.

Odontogenic differentiation and biomineralization potential of dental pulp stem cells inside Mg-based bioceramic scaffolds under low-level laser treatment.

This study aimed to investigate the potential of low-level laser irradiation (LLLI) to promote odontogenic differentiation and biomineralization by dental pulp stem cells (DPSCs) seeded inside bioceramic scaffolds. Mg-based, Zn-doped bioceramic scaffolds, synthesized by the sol-gel technique, were spotted with DPSCs and exposed to LLLI at 660 nm with maximum output power of 140 mw at fluencies (a) 2 and 4 J/cm2 to evaluate cell viability/proliferation by the MTT assay and (b) 4 J/cm2 to evaluate cell differentiation, using real-time PCR (expression of odontogenic markers) and a p-nitrophenylphosphate (pNPP)-based assay for alkaline phosphatase (ALP) activity measurement. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis were used for structural/chemical characterization of the regenerated tissues. Exposure of the DPSCs/scaffold complexes to the proposed LLLI scheme was associated with statistically significant increase of odontogenesis-related markers (bone morphogenetic protein 2 (BMP-2): 22.4-fold, dentin sialophosphoprotein (DSPP): 28.4-fold, Osterix: 18.5-fold, and Runt-related transcription factor 2 (Runx2): 3.4-fold). ALP activity was significantly increased at 3 and 7 days inside the irradiated compared to that in the non-irradiated SC/DPSC complexes, but gradually decreased until 14 days. Newly formed Ca-P tissue was formed on the SC/DPSC complexes after 28 days of culture that attained the characteristics of bioapatite. Overall, LLLI treatment proved to be beneficial for odontogenic differentiation and biomineralization of DPSCs inside the bioceramic scaffolds, making this therapeutic modality promising for targeted dentin engineering.