Polyesters with main and side chain phosphoesters as structural motives for biocompatible electrospun fibres

Phosphoester containing polymers are promising materials in biomedical applications due to their biocompatibility and biodegradability. Utilising thiol-ene chemistry, the synthesis of two novel structural polymer motives combining polyesters and phophoester groups was explored. The first polymer was obtained by coupling ene-functional poly(thioether-phosphoester) with thiol functional poly(pentadecalactone). While the coupling reaction was successful, yields remained low presumably due to inadequate endgroup stoichiometry. The second polymer comprised phosphoester side groups conjugated to unsaturated poly(globalide). Double bond conversions up to 84% were achieved depending of the type of phosphoester thiol and relative reactant ratios. The resulting polymers transitioned from solid semicrystaline to liquid amorphous with increasing degree of phosphoester conjugation. Electrospun fibres from polymers with 14% phosphoester conjugation allowed attachment and survival of human dermal fibroblasts, indicating their biocompatibility. These polymers represent a new class of easily accessible biocompatible polyester-phosphoester hybrid materials as potential building blocks for tunable biomaterials

Noncommutative Geometry and Symplectic Field Theory

In this work we study representations of the Poincare group defined over symplectic manifolds, deriving the Klein-Gordon and the Dirac equation in phase space. The formalism is associated with relativistic Wigner functions; the Noether theorem is derived in phase space and an interacting field, including a gauge field, approach is discussed.Comment: To appear in Physics Letters

Bone Flap Management In Neurosurgery

Bone flap removal procedure is growing in frequency in neurosurgical practice. Decompressive craniotomy has gained more scientifical evidences of its therapeutical value in post-traumatic brain swelling, in cerebrovascular diseases and in brain edema non - responding to clinical treatment after elective surgeries. Bone flap destination after craniotomy has many possible fates. We present a literature review of bone flap management in neurosurgical practice: technical preservation of bone flaps (under the scalp, in the abdominal wall, frozen), when to remove the bone flap and what to do when it is dropped during the craniotomy or is infected.172133137Movassaghi, K., Ver Halen, J., Ganchi, P., Amin-Hanjani, S., Mesa, J., Yaremchuk, M.J., Cranioplasty with subcutaneously preserved autologous bone grafts (2006) Plast Reconstr Surg, 117 (1), pp. 202-206Hauptli, J., Segantini, P., New tissue preservation method for bone flaps following decompressive craniotomy (1980) Helv Chir Acta, 47 (1-2), pp. 121-124Tybor, K., Fortuniak, J., Komunski, P., Papiez, T., Andrzejak, S., Jaskólski, D., Supplementation of cranial defects by an autologous bone flap stored in the abdominal wall (2005) Neurol Neurochir Pol, 39 (3), pp. 220-224Josan, V.A., Sgouros, S., Walsh, A.R., Dover, M.S., Nishikawa, H., Hockley, A.D., Cranioplasty in children (2005) Childs Nerv Syst, 21 (3), pp. 200-204Flannery, T., McConnell, R.S., Cranioplasty: Why throw the bone flap out? (2001) Br J Neurosurg, 15 (6), pp. 518-520Krishnan, P., Bhattacharyya, A.K., Sil, K., De, R., Bone flap preservation after decompressive craniectomy - experience with 55 cases (2006) Neurol India, 54 (3), pp. 291-292Korfali, E., Aksoy, K., Preservation of craniotomy bone flaps under the scalp (1988) Surg Neurol, 30 (4), pp. 269-272Goel, A., Deogaonkar, M., Subgaleal preservation of calvarial flaps (1995) Surg Neurol, 44 (2), pp. 181-182. , Aug;, discussion 182-3Pasaoglu, A., Kurtsoy, A., Koc, R.K., Kontas, O., Akdemir, H., Öktem, I.S., Cranioplasty with bone flaps preserved under the scalp (1996) Neurosurg Rev, 19 (3), pp. 153-156Iwama, T., Yamada, J., Imai, S., Shinoda, J., Funakoshi, T., Sakai, N., The use of frozen autogenous bone flaps in delayed cranioplasty revisited (2003) Neurosurgery, 52 (3), pp. 591-596Winkler, P.A., Stummer, W., Linke, R., Krishnan, K.G., Tatsch, K., The influence of cranioplasty on postural blood flow regulation, cerebrovascular reserve capacity, and cerebral glucose metabolism (2000) Neurosurg Focus, 8 (1), pp. e9Matsuno, A., Tanaka, H., Iwamuro, H., Takanashi, S., Miyawaki, S., Nakashima, M., Analyses of the factors influencing bone graft infection after delayed cranioplasty (2006) Acta Neurochir (Wien), 148 (5), pp. 535-540Yacubian-Fernandes, A., Laronga, P.R., Coelho, R.A., Ducati, L.G., Silva, M.V., Prototyping as an alternative to cranioplasty using methylmethacrylate: Technical, 62 (3 B), pp. 865-868. , note. Arq Neuropsiquiatr 2004;Chiarini, L., Figurelli, S., Pollastri, G., Torcia, E., Ferrari, F., Albanese, M., Cranioplasty using acrylic material: A new technical procedure (2004) J Craniomaxillofac Surg, 32 (1), pp. 5-9Korinek, A.M., Risk factors for neurosurgical site infections after craniotomy: A prospective multicenter study of 2944 patients. The French Study Group of Neurosurgical Infections, the SEHP, and the C-CLIN Paris-Nord. Service Epidemiologie Hygiene et Prevention (1997) Neurosurgery, 41 (5), pp. 1073-1079Bruce, J.N., Bruce, S.S., Preservation of bone flaps in patients with postcraniotomy infections (2003) J Neurosurg, 98 (6), pp. 1203-1207Auguste, K.I., McDermott, M.W., Salvage of infected craniotomy bone flaps with the wash-in, wash-out indwelling antibiotic irrigation system. Technical note and case series of 12 patients (2006) J Neurosurg, 105 (4), pp. 640-644Jankowitz, B.T., Kondziolka, D.S., When the bone flap hits the floor (2006) Neurosurgery, 59 (3), pp. 585-59

Non-linear Liouville and Shr\"odinger equations in phase space

Unitary representations of the Galilei group are studied in phase space, in order to describe classical and quantum systems. Conditions to write in general form the generator of time translation and Lagrangians in phase space are then established. In the classical case, Galilean invariance provides conditions for writing the Liouville operator and Lagrangian for non-linear systems. We analyze, as an example, a generalized kinetic equation where the collision term is local and non-linear. The quantum counter-part of such unitary representations are developed by using the Moyal (or star) product. Then a non-linear Schr\"odinger equation in phase space is derived and analyzed. In this case, an association with the Wigner formalism is established, which provides a physical interpretation for the formalism

Gravitational Collapse in Higher Dimensional Husain Space-Time

We investigate exact solution in higher dimensional Husain model for a null fluid source with pressure $p$ and density $\rho$ are related by the following relations (i) $p=k\rho$, (ii) $p=k\rho-\frac{B(v)}{\rho^{\alpha}}$ (variable modified Chaplygin) and (iii) $p=k\rho^{\alpha}$ (polytropic). We have studied the nature of singularity in gravitational collapse for the above equations of state and also for different choices of the of the parameters $k$ and $B$ namely, (i) $k=0$, $B=$ constant (generalized Chaplygin), (ii) $B=$ constant (modified Chaplygin). It is found that the nature of singularity is independent of these choices of different equation of state except for variable Chaplygin model. Choices of various parameters are shown in tabular form. Finally, matching of Szekeres model with exterior Husain space-time is done.Comment: 12 latex pages, No figure, RevTex styl

Four new coordination polymers involving transition metals with 1,2,4,5-benzenetetracarboxylate and pyridyl-donor ligand di(4-pyridyl) sulfide

AbstractFour new coordination polymers namely {[Mn2(BT)(DPS)2(H2O)6]·10H2O}n (MnBTDPS), {[Co2(BT)(DPS)2(H2O)6]·10H2O}n (CoBTDPS), {[Cu2(BT)(DPS)(H2O)4]·5H2O}n (CuBTDPS) and {[Zn2(BT)(DPS)2]·6H2O}n (ZnBTDPS), where BT=1,2,4,5-benzenetetracarboxylate and DPS=di(4-pyridyl) sulfide, were synthesized and characterized by thermal analysis, vibrational spectroscopy (Raman and infrared) and single crystal X-ray diffraction analysis. In all compounds, the DPS ligands are coordinated to metal sites in a bridging mode and the carboxylate moiety of BT ligands adopts a monodentate coordination mode, as indicated by the Raman spectra data through the Δν (νasym(COO)−ν sym(COO)) value. According to X-ray diffraction analysis, MnBTDPS and CoBTDPS are isostructural and in these cases, the metal centers exhibit a distorted octahedral geometry. In CuBTBPP, the Cu2+ centers geometries are best described as square-pyramids, according to the trigonality index τ=0.14 for Cu1 and τ=0.10 for Cu2. On the other hand, in ZnBTDPS, the Zn2+ sites adopt a tetrahedral geometry. Finally, the four compounds formed two-dimensional sheets that are connected to each other through hydrogen bonding giving rise to three-dimensional supramolecular arrays

Correlations equalities and some upper bounds for the critical temperature for spin one systems

Starting from correlation identities for the Blume-Capel spin 1 systems and using correlation inequalities, we obtain rigorous upper bounds for the critical temperature.The obtained results improve over effective field type results.Comment: 13 page

Space-time inhomogeneity, anisotropy and gravitational collapse

We investigate the evolution of non-adiabatic collapse of a shear-free spherically symmetric stellar configuration with anisotropic stresses accompanied with radial heat flux. The collapse begins from a curvature singularity with infinite mass and size on an inhomogeneous space-time background. The collapse is found to proceed without formation of an even horizon to singularity when the collapsing configuration radiates all its mass energy. The impact of inhomogeneity on various parameters of the collapsing stellar configuration is examined in some specific space-time backgrounds.Comment: To appear in Gen. Relativ. Gra