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Biomedical subjects

N Jakse

Publications and source records attributed to N Jakse.

9 recordsLinked to original sources
PubMed2006

Role of microchimerism in the pathogenesis of oral lichen planus.

OBJECTIVE: Microchimerism of persistent fetal cells has been implicated in some cell-mediated autoimmune diseases. This study examines the hypothesis that fetal microchimerism plays a role in the pathogenesis of lichen planus (LP) affecting the oral cavity. STUDY DESIGN: Mucosal biopsies of 12 women with oral LP (OLP) were tested for the presence of both male cells and male DNA originating from prior pregnancies or prior blood transfusions. Six male patients with OLP served as a control group. Biopsies were analyzed for the presence of Y-chromosome-positive cells by fluorescence in situ hybridization (FISH) with X- and Y-specific DNA probes. To confirm the FISH findings, we used fluorescent polymerase chain reaction (PCR) to identify Y-chromosome sequences in DNA extracted from mucosal lesions. RESULTS: Using FISH technology, all the 18 biopsy samples showed good hybridization results. In females, Y-chromosome-specific signals were not detected by FISH at any site of the lesions. PCR amplification demonstrated a single peak at the locus specific for the X-chromosome. CONCLUSION: Male DNA microchimerism was not present in any of the investigated lesions, suggesting that microchimerism because of persisting male fetal cells is unlikely to play a major role in the pathogenesis of OLP.

Adult↗
PubMed2005

Phase diagram of complex fluids using an efficient integral equation method.

We present an adaptive technique for the determination of the phase diagram of fluids within the integral equation theory. It enables an efficient and accurate systematic mapping of the thermodynamic space in order to construct the binodal and spinodal lines. Results are obtained with the thermodynamically consistent integral equation proposed by Sarkisov [J. Chem. Phys. 114, 9496 (2001)] within the tangent linear technique that yields an exact differentiation of correlation functions. The generality of the numerical approach is assessed by determining both the liquid-vapor coexistence and the critical parameters of the generalized Lennard-Jones (n,6) potentials with varying repulsive part, including the hard-sphere limit.

Journal Article↗
PubMed2005

Chemical and icosahedral short-range orders in liquid and undercooled Al80Mn20 and Al80Ni20 alloys: a first-principles-based approach.

Atomic structures of stable liquid and undercooled liquid Al(80)Mn(20) and Al(80)Ni(20) alloys have been calculated by first-principles molecular-dynamics simulations. For both alloys, the local structure as defined by the Faber-Ziman pair-correlation functions is characterized by a strong Al-transition-metal affinity, which leads to a well-pronounced chemical short-range order which is more temperature dependent for Al(80)Mn(20) than for Al(80)Ni(20). In addition, a structural analysis using three-dimensional pair analysis techniques has been performed in details. More particularly, we find that the fivefold local symmetry around Mn atoms is predominant in both stable and undercooled Al(80)Mn(20) alloys and displays no significant variation with temperatures. On the contrary, in Al(80)Ni(20), a strong variation of the topological short-range order is observed since in the undercooled state, the local environment of Ni atoms is characterized by the predominance of the fivefold symmetry over the close-packed local symmetry which is opposed to what occurs in the stable liquid phase.

Journal Article↗
PubMed2004

Ab initio molecular-dynamics simulations of short-range order in liquid Al80Mn20 and Al80Ni20 alloys.

Atomic structures of liquid Al80Mn20 and Al80Ni20 have been calculated by first-principles molecular-dynamics simulations. For both liquid alloys, the local structure is characterized by a strong Al-TM (transition metal) affinity, which leads to a well-pronounced chemical short-range order. However, we show that the occurrence of magnetic moments localized on Mn atoms plays a key role in determining the short-range arrangement of Mn atoms which is also interpreted on the basis of the local fivefold symmetry.

Journal Article↗
PubMed2003

Direct excess entropy calculation for a Lennard-Jones fluid by the integral equation method.

The present work is devoted to the calculation of excess entropy by means of correlation functions, in the framework of integral equation theory. The tangent linear method is set up to get exact thermodynamic derivatives of the pair-correlation function, essential for the calculation of the physical quantities, as well as to carry out an optimization process for the achievement of thermodynamic consistency. The two-body entropy of the Lennard-Jones fluid is in very good agreement with the available molecular dynamics results, attesting the high degree of accuracy of the integral equation scheme. It is shown that an accurate prediction of the excess entropy and the resulting residual multiparticle entropy relies on the correct evaluation of the excess chemical potential, especially at high density. Two independent routes to calculate the latter are compared, and the consequences are discussed.

Journal Article↗
PubMed2001

A modified technique of harvesting tibial cancellous bone and its use for sinus grafting.

Autogenous bone is the gold standard graft for sinus augmentation. The harvest of autogenous bone grafts from intraoral sites does often not provide sufficient bone volume and quality. A modified technique of harvesting a tibial cancellous graft is presented. With a micro-bone saw, a bony lid is prepared at the medial condyle of the tibia. The lid stays attached to the tendinous pes anserinus. Following the harvest, the lid is repositioned accurately. This method offers some distinct advantages. A sufficient amount of biologically highly valuable cancellous bone may be harvested for sinus grafting and possibly other surgeries with bone augmentation. The procedure may be performed under local anaesthesia and does not require hospitalisation. Neither major complications nor serious postoperative morbidity were observed.

Alveolar Ridge Augmentation↗
PubMed2000

Effects of dispersion forces on the structure and thermodynamics of fluid krypton

Semianalytical and numerical calculations are performed to predict the structural and thermodynamic properties of low-density Kr fluid. Assuming that the interatomic forces can be modelled by a pairwise potential plus the three-body Axilrod-Teller potential, two different routes are explored. The first one is based on the hybridized mean spherical approximation integral equation of the theory of liquids and the second one uses large-scale molecular dynamics (MD). Algorithms for MD simulation are constructed on parallel machines to reduce the amount of computer time induced by the calculations of the three-body forces and the pair-correlation function. Our results obtained with the two methods mentioned above are in quite good agreement with the recent small-angle neutron-scattering experiments [Formisano et al., Phys. Rev. Lett. 79, 221 (1997); Benmore et al., J. Phys.: Condens. Matter 11, 3091 (1999)]. Moreover, the reliability of the asymptotic form of the integral equation is assessed for the specific case of dispersion forces including the three-body contributions, by an analysis at low wave vector and low density. It is seen that the effects of the Axilrod-Teller triple-dipole potential cannot be ignored to describe the structure and the thermodynamic properties of fluid krypton even at low density.

Journal Article↗