5,383 research outputs found
Clinical, Instrumental and Immunological Follow-Up of Patients with Brain Tumors
Dynamic assessment of 66 patients with different brain tumours was carried out. The clinical, immunological and instrumental (electrophysiological and neuroimaging) follow-up included three groups of cases with stable clinical course, tumour progression and recurrence. Our results confirm that the changes in the functional and immune status of the patients with cerebral neoplasms as well as the alterations in the cerebral function and structure reflect the tumour development and the corresponding therapeutic behaviour. Monitoring of patients status and tumour growth provides opportunity for better disease control and prognosis
Advances in Three Dimensional Printing - state of the art and future perspectives
Published ArticleThis paper surveys the current state and capabilities of Three Dimensional Printing (3DP). Based on its technical background - the ink jet printing as known from the printer and plotter industry - a classification structure has been developed and proposed. Different printing techniques and process concepts, together with their advantages and limitations are described and analysed. A large variety of manufacturing applications such as rapid pattern making and rapid tooling using the 3DP process directly or as core technology, as well as further implications in design and engineering analysis, medicine, and architecture are presented and evaluated. Some research issues are also discussed. An attempt, based on the state of the art, to show weaknesses and opportunities, and to draw conclusions about the future of this important process wraps up this paper
Polymer Brushes in Cylindrical Pores: Simulation versus Scaling Theory
The structure of flexible polymers endgrafted in cylindrical pores of
diameter D is studied as a function of chain length N and grafting density
\sigma, assuming good solvent conditions. A phenomenological scaling theory,
describing the variation of the linear dimensions of the chains with \sigma, is
developed and tested by Molecular Dynamics simulations of a bead-spring model.Comment: 35 pages, 38 figure
Molekularna genetika i SSR markeri kao nova praksa u genomskoj analizi farmskih životinja u reprodukciji i kontroli bolesti
Molecular genetics investigates the genetic makeup of individuals at the DNA level. That includes the identification and mapping of molecular genetic markers and genetic polymorphisms. Molecular genetic markers (DNA markers) are one of the most powerful means for the genomic analysis and allow the connection of hereditary traits with genomic variation. Molecular marker technology has developed rapidly over the last decade and two shapes of specific DNA based marker, Simple Sequence Repeats (SSRs), also known as microsatellites, and Single Nucleotide Polymorphisms (SNPs) prevail applications in modern genetic analysis. Genomic simple sequence repeats (SSRs, microsatellites) have been used for a variety of purposes, including gene tagging, physical mapping, genome mapping, estimation of genetic diversity, phylogenetic and conservation genetic purposes in farm animal breeding. SSR analyses are applied successfully in parentage verification and pedigree analysis, as disease markers and to locate the mutation in genetic disorders in livestock animals. The ultimate use of SSRs markers is for mapping quantitative trait loci (QTL), marker assisted selection (MAS) in order to practice genomic selection and improve the farm animal health. Developments in 'omics' technologies, such as genomic selection, may help overcome several of the limitations of traditional breeding programmes and will be especially beneficial in breeding for lowly heritable disease traits that only manifest themselves following exposure to pathogens or environmental stressors in adulthood. The current paper provides a brief overview of the present - day application of microsatellites markers in animal breeding and make significant contribution to the overall farm animal health and resistance to disease.Molekularna genetika istražuje genetski sastav pojedinaca na nivou DNK. To uključuje identifikaciju i mapiranje molekularnih genetskih markera i genetskih polimorfizama. Molekularni genetski markeri (DNK markeri) su jedan od najmoćnijih sredstava genomske analize i pružaju mogućnost povezivanja naslednih osobina sa genomskim varijacijama. Tehnologija molekularnih markera se brzo razvila u poslednjoj deceniji, a dva oblika markera na bazi DNK, Simple Sequence Repeats (SSR), takođe poznati kao mikrosateliti, i polimorfizam pojedinačnih nukleotida - Single Nucleotide Polymorphisms (SNP) preovlađuju u primeni u modernoj genetskoj analizi. Genomske sekvence - ponavljanja (Simple Sequence Repeats - SSR, mikrosateliti) se koriste za razne svrhe, uključujući označavanje gena, fizičko mapiranje, mapiranje genoma, procena genetičke raznovrsnosti, filogenetske i u svrhu genetičke konzervacije u uzgoju farmskih životinja. SSR analiza se uspešno primenjuju u verifikaciji roditeljstva, i analizi pedigrea, kao markeri bolesti i u pronalaženju mutacije i genetskih poremećaja kod farmskih životinja. Krajnja upotreba SSR markera je za mapiranje lokusa kvantitativnih osobina (QTL), selekciji pomoću markera (MAS), kako bi se u praksi primenjivala genomska selekciju i unapređenje zdravlja farmskih životinja. Razvoj u tehnologijama 'omics'', kao što je genomska selekcija, može pomoći u prevazilaženju nekoliko ograničenja tradicionalnih odgajivačkih programa a posebno će biti korisna za oplemenjivanje i odgoj na nižu naslednost naslednih osobina bolesti koje se ispoljavaju tek nakon izloženosti patogenima ili ekološkim stresorima u odraslom dobu. Ovaj rad daje kratak pregled današnje primene mikrosatelit markera u stočarstvu i daje značajan doprinos ukupnom zdravlju životinja uzgajanih na farmi i otpornosti na bolesti
Advances in surface EMG signal simulation with analytical and numerical descriptions of the volume conductor
Surface electromyographic (EMG) signal modeling is important for signal interpretation, testing of processing algorithms, detection system design, and didactic purposes. Various surface EMG signal models have been proposed in the literature. In this study we focus on 1) the proposal of a method for modeling surface EMG signals by either analytical or numerical descriptions of the volume conductor for space-invariant systems, and 2) the development of advanced models of the volume conductor by numerical approaches, accurately describing not only the volume conductor geometry, as mainly done in the past, but also the conductivity tensor of the muscle tissue. For volume conductors that are space-invariant in the direction of source propagation, the surface potentials generated by any source can be computed by one-dimensional convolutions, once the volume conductor transfer function is derived (analytically or numerically). Conversely, more complex volume conductors require a complete numerical approach. In a numerical approach, the conductivity tensor of the muscle tissue should be matched with the fiber orientation. In some cases (e.g., multi-pinnate muscles) accurate description of the conductivity tensor may be very complex. A method for relating the conductivity tensor of the muscle tissue, to be used in a numerical approach, to the curve describing the muscle fibers is presented and applied to representatively investigate a bi-pinnate muscle with rectilinear and curvilinear fibers. The study thus propose an approach for surface EMG signal simulation in space invariant systems as well as new models of the volume conductor using numerical methods
Magnetocaloric Studies of the Peak Effect in Nb
We report a magnetocaloric study of the peak effect and Bragg glass
transition in a Nb single crystal. The thermomagnetic effects due to vortex
flow into and out of the sample are measured. The magnetocaloric signature of
the peak effect anomaly is identified. It is found that the peak effect
disappears in magnetocaloric measurements at fields significantly higher than
those reported in previous ac-susceptometry measurements. Investigation of the
superconducting to normal transition reveals that the disappearance of the bulk
peak effect is related to inhomogeneity broadening of the superconducting
transition. The emerging picture also explains the concurrent disappearance of
the peak effect and surface superconductivity, which was reported previously in
the sample under investigation. Based on our findings we discuss the
possibilities of multicriticality associated with the disappearance of the peak
effect.Comment: 30 pages, 10 figure
Monte Carlo study of the critical temperature for the planar rotator model with nonmagnetic impurities
We performed Monte Carlo simulations to calculate the
Berezinskii-Kosterlitz-Thouless (BKT) temperature for the
two-dimensional planar rotator model in the presence of nonmagnetic impurity
concentration . As expected, our calculation shows that the BKT
temperature decreases as the spin vacancies increase. There is a critical
dilution at which . The effective interaction
between a vortex-antivortex pair and a static nonmagnetic impurity is studied
analytically. A simple phenomenological argument based on the pair-impurity
interaction is proposed to justify the simulations.Comment: 5 pages, 5 figures, Revetex fil
Multi-site campaign for transit timing variations of WASP-12 b: possible detection of a long-period signal of planetary origin
The transiting planet WASP-12 b was identified as a potential target for
transit timing studies because a departure from a linear ephemeris was reported
in the literature. Such deviations could be caused by an additional planet in
the system. We attempt to confirm the existence of claimed variations in
transit timing and interpret its origin. We organised a multi-site campaign to
observe transits by WASP-12 b in three observing seasons, using 0.5-2.6-metre
telescopes. We obtained 61 transit light curves, many of them with
sub-millimagnitude precision. The simultaneous analysis of the best-quality
datasets allowed us to obtain refined system parameters, which agree with
values reported in previous studies. The residuals versus a linear ephemeris
reveal a possible periodic signal that may be approximated by a sinusoid with
an amplitude of 0.00068+/-0.00013 d and period of 500+/-20 orbital periods of
WASP-12 b. The joint analysis of timing data and published radial velocity
measurements results in a two-planet model which better explains observations
than single-planet scenarios. We hypothesize that WASP-12 b might be not the
only planet in the system and there might be the additional 0.1 M_Jup body on a
3.6-d eccentric orbit. A dynamical analysis indicates that the proposed
two-planet system is stable over long timescales.Comment: Accepted for publication in A&
Molecular basis for bacterial peptidoglycan recognition by LysM domains.
Carbohydrate recognition is essential for growth, cell adhesion and signalling in all living organisms. A highly conserved carbohydrate binding module, LysM, is found in proteins from viruses, bacteria, fungi, plants and mammals. LysM modules recognize polysaccharides containing N-acetylglucosamine (GlcNAc) residues including peptidoglycan, an essential component of the bacterial cell wall. However, the molecular mechanism underpinning LysM-peptidoglycan interactions remains unclear. Here we describe the molecular basis for peptidoglycan recognition by a multimodular LysM domain from AtlA, an autolysin involved in cell division in the opportunistic bacterial pathogen Enterococcus faecalis. We explore the contribution of individual modules to the binding, identify the peptidoglycan motif recognized, determine the structures of free and bound modules and reveal the residues involved in binding. Our results suggest that peptide stems modulate LysM binding to peptidoglycan. Using these results, we reveal how the LysM module recognizes the GlcNAc-X-GlcNAc motif present in polysaccharides across kingdoms
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