Histological and morphometric aspects of ridge preservation with a moldable, in situ hardening bone graft substitute

Biphasic calcium phosphates (BCP) are widely used in alveolar ridge regeneration as a porous scaffold for new bone formation. The aim of this case series was to evaluate the regenerative effect of the combination of BCP and polylactide-co-glycolide (PLGA) which can serve as a barrier membrane during bone regeneration. The study included five patients. Four months into the healing period, bone samples were collected for histological and morphometric analyses. The results of morphometric analysis showed that newly formed bone represented 32.2 ± 6.8% of the tissue, 31.9 ± 8.9% was occupied by residual graft and 35.9 ± 13.5% by soft tissue. Active osteogenesis was seen around the particles of the graft. The particles were occupied mostly by immature woven bone and connective tissue. The quality and quantity of newly formed bone, after the use of BCP/PLGA for ridge preservation, can be adequate for successful implant therapy after tooth extraction.Projekat ministarstva br. OI 175021 i br. OI 17300

Magnetic field diagnostics and spatio-temporal variability of the solar transition region

Magnetic field diagnostics of the transition region from the chromosphere to the corona faces us with the problem that one has to apply extreme UV spectro-polarimetry. While for coronal diagnostic techniques already exist through infrared coronagraphy above the limb and radio observations on the disk, for the transition region one has to investigate extreme UV observations. However, so far the success of such observations has been limited, but there are various projects to get spectro-polarimetric data in the extreme UV in the near future. Therefore it is timely to study the polarimetric signals we can expect for such observations through realistic forward modeling. We employ a 3D MHD forward model of the solar corona and synthesize the Stokes I and Stokes V profiles of C IV 1548 A. A signal well above 0.001 in Stokes V can be expected, even when integrating for several minutes in order to reach the required signal-to-noise ratio, despite the fact that the intensity in the model is rapidly changing (just as in observations). Often this variability of the intensity is used as an argument against transition region magnetic diagnostics which requires exposure times of minutes. However, the magnetic field is evolving much slower than the intensity, and thus when integrating in time the degree of (circular) polarization remains rather constant. Our study shows the feasibility to measure the transition region magnetic field, if a polarimetric accuracy on the order of 0.001 can be reached, which we can expect from planned instrumentation.Comment: Accepted for publication in Solar Physics (4.Mar.2013), 19 pages, 9 figure

Functionalization of graphene nanoplatelets via Bingel reaction for polymer nanocomposites

In this study, we have performed functionalization of graphene nanoplatelets (GNPs) via Bingel reaction and investigated influence on the addition of covalently functionalized GPNs on the structural changes of the poly(methyl methacrylate). Preparation of poly(methyl methacrylate) nanocomposites with functionalized GNPs has been accomplished by drop casting method of dissolved PMMA mixed with modified graphene nanoplatelets dispersed in a N-methyl-1-pyrrolidone. Functionalizaton of graphene has been achieved under the conditions of Bingel reaction, which implies introduction of diethyl malonate on the graphene surfaces through the cyclopropane ring formation. Introduction of the cyclopropane ring on to the surface of graphene does not significantly affect the initial structural properties of graphene nanoplatelets, allowing better dispersible properties due to interaction of covalently attached diethyl malonate groups with the polymer chains. Fourier transform infrared spectroscopy (FTIR) and elemental analysis confirmed the effectiveness of the addition of diethyl malonate via Bingel reaction on the surface of GNPs. Scanning electron microscopy (SEM) has been used to provide information on the morphology of functionalized GNPs. Prepared nanocomposites have been characterized by Raman and FTIR spectroscopy. The changes regarding glass transition temperature have been monitored with differential scanning calorimetry (DSC)

Explosive events - swirling transition region jets

In this paper, we extend our earlier work to provide additional evidence for an alternative scenario to explain the nature of so-called `explosive events'. The bi-directed, fast Doppler motion of explosive events observed spectroscopically in the transition region emission is classically interpreted as a pair of bidirectional jets moving upward and downward from a reconnection site. We discuss the problems of such a model. In our previous work, we focused basically on the discrepancy of fast Doppler motion without detectable motion in the image plane. We now suggest an alternative scenario for the explosive events, based on our observations of spectral line tilts and bifurcated structure in some events. Both features are indicative of rotational motion in narrow structures. We explain the bifurcation as the result of rotation of hollow cylindrical structures and demonstrate that such a sheath model can also be applied to explain the nature of the puzzling `explosive events'. We find that the spectral tilt, the lack of apparent motion, the bifurcation, and a rapidly growing number of direct observations support an alternative scenario of linear, spicular-sized jets with a strong spinning motion.Comment: 9 pages, 3 figures, accepted for publication in Solar Physic

Histological and morphometric aspects of ridge preservation with a moldable, in situ hardening bone graft substitute

Biphasic calcium phosphates (BCP) are widely used in alveolar ridge regeneration as a porous scaffold for new bone formation. The aim of this case series was to evaluate the regenerative effect of the combination of BCP and polylactide-co-glycolide (PLGA) which can serve as a barrier membrane during bone regeneration. The study included five patients. Four months into the healing period, bone samples were collected for histological and morphometric analyses. The results of morphometric analysis showed that newly formed bone represented 32.2 ± 6.8% of the tissue, 31.9 ± 8.9% was occupied by residual graft and 35.9 ± 13.5% by soft tissue. Active osteogenesis was seen around the particles of the graft. The particles were occupied mostly by immature woven bone and connective tissue. The quality and quantity of newly formed bone, after the use of BCP/PLGA for ridge preservation, can be adequate for successful implant therapy after tooth extraction.Projekat ministarstva br. OI 175021 i br. OI 17300

How to use magnetic field information for coronal loop identification?

The structure of the solar corona is dominated by the magnetic field because the magnetic pressure is about four orders of magnitude higher than the plasma pressure. Due to the high conductivity the emitting coronal plasma (visible e.g. in SOHO/EIT) outlines the magnetic field lines. The gradient of the emitting plasma structures is significantly lower parallel to the magnetic field lines than in the perpendicular direction. Consequently information regarding the coronal magnetic field can be used for the interpretation of coronal plasma structures. We extrapolate the coronal magnetic field from photospheric magnetic field measurements into the corona. The extrapolation method depends on assumptions regarding coronal currents, e.g. potential fields (current free) or force-free fields (current parallel to magnetic field). As a next step we project the reconstructed 3D magnetic field lines on an EIT-image and compare with the emitting plasma structures. Coronal loops are identified as closed magnetic field lines with a high emissivity in EIT and a small gradient of the emissivity along the magnetic field.Comment: 14 pages, 3 figure

Reciprocal Associations between Parenting Challenges and Parents' Personality Development in Young and Middle Adulthood

Having children affects many aspects of people's lives. However, it remains unclear to what degree the challenges that come along with having children are associated with parents' personality development. We addressed this question in two studies by investigating the relationship between parenting challenges and personality development in mothers of newborns (Study 1, N = 556) and the reciprocal associations between (mastering) parenting challenges and personality development in parents of adolescents (Study 2, N = 548 mothers and 460 fathers). In Study 1, we found the stress of having a newborn baby to be associated with declines in maternal Agreeableness, Conscientiousness, and Emotional Stability. Parenting challenges were also related to personality development in parents of adolescent children in Study 2, with parent–child conflict being reciprocally associated with decreases in Conscientiousness and Emotional Stability. Mastering parenting challenges in the form of high parenting self-efficacy, on the other hand, was found to be associated with increases in Agreeableness, Conscientiousness, and Emotional Stability, and vice versa. In sum, our results suggest that mastering the challenges associated with the social role of parenthood is one of the mechanisms underlying personality development in young and middle adulthood

ADSORPTION OF METHYLENE BLUE DYE ON ACTIVATED CARBON OBTAINED FROM THE FRUIT OF PLANE TREES

The fruit of plane trees is used to obtain the powdered activated carbon. As the activating agent is used in the preparation of concentrated phosphoric acid. Completed the equilibrium adsorption of cationic methylene blue dye in the synthesized material. These results were fitted with three adsorption equilibrium model. The experimental results were analyzed by the Langmuir isotherm, Freundlich isotherm in the Temkin isotherm. The best fit of the experimental results with theoretical models is obtained in the case of Langmuir's equilibrium models. According to the Langmuir model, achieved the best adsorption capacity of the adsorbent color which is 354.60 mg g-1 when activated carbon treated with NaOH

Histological and morphometric aspects of ridge preservation with a moldable, in situ hardening bone graft substitute

Biphasic calcium phosphates (BCP) are widely used in alveolar ridge regeneration as a porous scaffold for new bone formation. The aim of this case series was to evaluate the regenerative effect of the combination of BCP and polylactide-co-glycolide (PLGA) which can serve as a barrier membrane during bone regeneration. The study included five patients. Four months into the healing period, bone samples were collected for histological and morphometric analyses. The results of morphometric analysis showed that newly formed bone represented 32.2 ± 6.8% of the tissue, 31.9 ± 8.9% was occupied by residual graft and 35.9 ± 13.5% by soft tissue. Active osteogenesis was seen around the particles of the graft. The particles were occupied mostly by immature woven bone and connective tissue. The quality and quantity of newly formed bone, after the use of BCP/PLGA for ridge preservation, can be adequate for successful implant therapy after tooth extraction. [Projekat Ministarstva nauke Republike Srbije, br. OI 175021 i br. OI 173009