Ultrasound mapping of lymph node and subcutaneous metastases in patients with cutaneous melanoma: Results of a prospective multicenter study

Background: Ultrasound (sonography, B-mode sonography, ultrasonography) examination improves the sensitivity in more than 25% compared to the clinical palpation, especially after surgery on the regional lymph node area. Objective: To evaluate the distribution of metastases during follow-up in the draining lymph node areas from the scar of primary to regional lymph nodes ( head and neck, supraclavicular, axilla, infraclavicular, groin) in patients with cutaneous melanoma with or without sentinel lymph node biopsy (SLNB) or former elective or consecutive complete lymph node dissection in case of positive sentinel lymph node (CLND). Methods: Prospective multicenter study of the Departments of Dermatology of the Universities of Homburg/Saar, Tubingen and Munich (Germany) in which the distribution of lymph node and subcutaneous metastases were mapped from the scar of primary to the lymphatic drainage region in 53 melanoma patients ( 23 women, 30 men; median age: 64 years; median tumor thickness: 1.99 mm) with known primary, visible lymph nodes or subcutaneous metastases proven by ultrasound and histopathology during the follow-up. Results: Especially in the axilla, infraclavicular region and groin the metastases were not limited to the anatomic lymph node regions. In 5 patients (9.4%) ( 4 of them were in stage IV) lymph node metastases were not located in the corresponding lymph node area. 32 patients without former SLNB had a time range between melanoma excision and lymph node metastases of 31 months ( median), 21 patients with SLNB had 18 months ( p < 0.005). In 11 patients with positive SLNB the time range was 17 months, in 10 patients with negative SLNB 21 months ( p < 0.005); in 32 patients with CLND the time range was 31 m< 0.005). In thinner melanomas lymph node metastases occurred later ( p < 0.05). Conclusions: After surgery of cutaneous melanoma, SLNB and CLND the lymphatic drainage can show significant changes which should be considered in clinical and ultrasound follow-up examinations. Especially for high-risk melanoma patients follow-up examinations should be performed at intervals of 3 months in the first years. Patients at stage IV should be examined in all regional lymph node areas clinically and by ultrasound. Copyright (c) 2006 S. Karger AG, Basel

Effect of tibial plateau angle < 5° on ground reaction forces in dogs treated with tibial plateau leveling osteotomy for cranial cruciate ligament rupture up to 6 months postoperatively

Tibial plateau leveling osteotomy (TPLO) has been commonly performed in dogs with cranial cruciate ligament disease (CCLD) since the introduction by Slocum and Slocum (1993). To reduce cranial tibial thrust the TPLO technique aims for a postoperative tibial plateau angle (TPA) of 5–6.5°. In recent years studies have shown that a postoperative TPA below 5° could be beneficial regarding stifle stability or meniscal load. Dogs with CCLD that were treated with TPLO, were examined preoperatively, six weeks, three and six months postoperatively with gait analysis and grouped according to their postoperative TPA. The aims of study was (1) to evaluate if dogs with a postoperative TPA below 5° would have a faster limb function recovery up to six months postoperatively as measured objectively with ground reaction forces (GRFs) and (2) to determine whether the postoperative TPA correlates with the outcome measurements. Dogs with TPA 0.05). No correlation for the postoperative TPA 5° and <5° TPA together), indicating that with lower postoperative TPA dogs had a more symmetrical gait in hindlimbs SIPVF (r = 0.144, p < 0.05) and SIVI (r = 0.189, p < 0.01). The study indicates that a lower postoperative TPA could be beneficial regarding hindlimb symmetry indices of GRFs

SLE local martingales in logarithmic representations

A space of local martingales of SLE type growth processes forms a representation of Virasoro algebra, but apart from a few simplest cases not much is known about this representation. The purpose of this article is to exhibit examples of representations where L_0 is not diagonalizable - a phenomenon characteristic of logarithmic conformal field theory. Furthermore, we observe that the local martingales bear a close relation with the fusion product of the boundary changing fields. Our examples reproduce first of all many familiar logarithmic representations at certain rational values of the central charge. In particular we discuss the case of SLE(kappa=6) describing the exploration path in critical percolation, and its relation with the question of operator content of the appropriate conformal field theory of zero central charge. In this case one encounters logarithms in a probabilistically transparent way, through conditioning on a crossing event. But we also observe that some quite natural SLE variants exhibit logarithmic behavior at all values of kappa, thus at all central charges and not only at specific rational values.Comment: 40 pages, 7 figures. v3: completely rewritten, new title, new result

Using Rheo-Small-Angle Neutron Scattering to Understand How Functionalised Dipeptides Form Gels

We explore the use of rheo-small-angle neutron scattering as a method to collect structural information from neutron scattering simultaneously with rheology to understand how low-molecular-weight hydrogels form and behave under shear. We examine three different gelling hydrogel systems to assess what structures are formed and how these influence the rheology. Furthermore, we probe what is happening to the network during syneresis and why the gels do not recover after an applied strain. All this information is vital when considering gels for applications such as 3D-printing and injection

Random walks on activity-driven networks with attractiveness

Virtually all real-world networks are dynamical entities. In social networks, the propensity of nodes to engage in social interactions (activity) and their chances to be selected by active nodes (attractiveness) are heterogeneously distributed. Here, we present a time-varying network model where each node and the dynamical formation of ties are characterized by these two features. We study how these properties affect random-walk processes unfolding on the network when the time scales describing the process and the network evolution are comparable. We derive analytical solutions for the stationary state and the mean first-passage time of the process, and we study cases informed by empirical observations of social networks. Our work shows that previously disregarded properties of real social systems, such as heterogeneous distributions of activity and attractiveness as well as the correlations between them, substantially affect the dynamical process unfolding on the network

Proposal for a CFT interpretation of Watts' differential equation for percolation

G. M. T. Watts derived that in two dimensional critical percolation the crossing probability Pi_hv satisfies a fifth order differential equation which includes another one of third order whose independent solutions describe the physically relevant quantities 1, Pi_h, Pi_hv. We will show that this differential equation can be derived from a level three null vector condition of a rational c=-24 CFT and motivate how this solution may be fitted into known properties of percolation.Comment: LaTeX, 20p, added references, corrected typos and additional content

Time separation as a hidden variable to the Copenhagen school of quantum mechanics

The Bohr radius is a space-like separation between the proton and electron in the hydrogen atom. According to the Copenhagen school of quantum mechanics, the proton is sitting in the absolute Lorentz frame. If this hydrogen atom is observed from a different Lorentz frame, there is a time-like separation linearly mixed with the Bohr radius. Indeed, the time-separation is one of the essential variables in high-energy hadronic physics where the hadron is a bound state of the quarks, while thoroughly hidden in the present form of quantum mechanics. It will be concluded that this variable is hidden in Feynman's rest of the universe. It is noted first that Feynman's Lorentz-invariant differential equation for the bound-state quarks has a set of solutions which describe all essential features of hadronic physics. These solutions explicitly depend on the time separation between the quarks. This set also forms the mathematical basis for two-mode squeezed states in quantum optics, where both photons are observable, but one of them can be treated a variable hidden in the rest of the universe. The physics of this two-mode state can then be translated into the time-separation variable in the quark model. As in the case of the un-observed photon, the hidden time-separation variable manifests itself as an increase in entropy and uncertainty.Comment: LaTex 10 pages with 5 figure. Invited paper presented at the Conference on Advances in Quantum Theory (Vaxjo, Sweden, June 2010), to be published in one of the AIP Conference Proceedings serie

Studies on metal-organic frameworks of Cu(II) with isophthalate linkers for hydrogen storage

Hydrogen (H2) is a promising alternative energy carrier due to its environmental benefits, high energy density and its abundance. However, development of a practical storage system to enable the “Hydrogen Economy” remains a huge challenge. Metal-organic frameworks (MOFs) are an important class of crystalline coordination polymers constructed by bridging metal centers with organic linkers, and show promise for H2 storage due to their high surface area and tuneable properties. We summarize our research on novel porous materials with enhanced H2 storage properties, and describe frameworks derived from 3,5-substituted dicarboxylates (isophthalates) that serve as versatile molecular building blocks for the construction of a range of interesting coordination polymers with Cu(II) ions. A series of materials has been synthesised by connecting linear tetracarboxylate linkers to {Cu(II)2} paddlewheel moieties. These (4,4)-connected frameworks adopt the fof-topology in which the Kagomé lattice layers formed by {Cu(II)2} paddlewheels and isophthalates are pillared by the bridging ligands. These materials exhibit high structural stability and permanent porosity, and the pore size, geometry and functionality can be modulated by variation of the organic linker to control the overall H2 adsorption properties. NOTT-103 shows the highest H2 storage capacity of 77.8 mg g−1 at 77 K, 60 bar among the fof-type frameworks. H2 adsorption at low, medium and high pressures correlates with the isosteric heat of adsorption, surface area and pore volume, respectively. Tri-branched C3-symmetric hexacarboxylate ligands with Cu(II) give highly porous (3,24)-connected frameworks incorporating {Cu(II)2} paddlewheels. These ubt-type frameworks comprise three types of polyhedral cage: a cuboctahedron, truncated tetrahedron and a truncated octahedron which are fused in the solid state in the ratio 1:2:1, respectively. Increasing the length of the hexacarboxylate struts directly tunes the porosity of the resultant material from micro- to mesoporosity. These materials show exceptionally high H2 uptakes owing to their high surface area and pore volume. NOTT-112, the first reported member of this family reported, adsorbs 111 mg g−1 of H2 at 77 K , 77 bar. More recently, enhanced H2 adsorption in these ubt-type frameworks has been achieved using combinations of polyphenyl groups linked by alkynes to give an overall gravimetric gas capacity for NU-100 of 164 mg g−1 at 77 K, 70 bar. However, due to its very low density NU-100 shows a lower volumetric capacity of 45.7 g L-1 compared with 55.9 g L-1 for NOTT-112, which adsorbs 2.3 wt% H2 at 1 bar, 77K. This significant adsorption of H2 at low pressures is attributed to the arrangement of the {Cu24(isophthalate)24} cuboctahedral cages within the polyhedral structure. Free metal coordination positions are the first binding sites for D2, and in these ubt-type frameworks there are two types of Cu(II) centres, one with its vacant site pointing into the cuboctahedral cage and another pointing externally. D2 molecules bind first at the former position, and then at the external open metal sites. However, other adsorption sites between the cusp of three phenyl groups and a Type I pore window in the framework are also occupied. Ligand and complex design feature strongly in enhancing and maximising H2 storage, and, although current materials operate at 77 K, research continues to explore routes to high capacity H2 storage materials that can function at higher temperatures

Endothelin receptor B antagonists decrease glioma cell viability independently of their cognate receptor

Background: Endothelin receptor antagonists inhibit the progression of many cancers, but research into their influence on glioma has been limited. Methods: We treated glioma cell lines, LN-229 and SW1088, and melanoma cell lines, A375 and WM35, with two endothelin receptor type B (ETRB)-specific antagonists, A-192621 and BQ788, and quantified viable cells by the capacity of their intracellular esterases to convert non-fluorescent calcein AM into green-fluorescent calcein. We assessed cell proliferation by labeling cells with carboxyfluorescein diacetate succinimidyl ester and quantifying the fluorescence by FACS analysis. We also examined the cell cycle status using BrdU/propidium iodide double staining and FACS analysis. We evaluated changes in gene expression by microarray analysis following treatment with A-192621 in glioma cells. We examined the role of ETRB by reducing its expression level using small interfering RNA (siRNA). Results: We report that two ETRB-specific antagonists, A-192621 and BQ788, reduce the number of viable cells in two glioma cell lines in a dose- and time-dependent manner. We describe similar results for two melanoma cell lines. The more potent of the two antagonists, A-192621, decreases the mean number of cell divisions at least in part by inducing a G2/M arrest and apoptosis. Microarray analysis of the effects of A-192621 treatment reveals up-regulation of several DNA damage-inducible genes. These results were confirmed by real-time RT-PCR. Importantly, reducing expression of ETRB with siRNAs does not abrogate the effects of either A-192621 or BQ788 in glioma or melanoma cells. Furthermore, BQ123, an endothelin receptor type A (ETRA)-specific antagonist, has no effect on cell viability in any of these cell lines, indicating that the ETRB-independent effects on cell viability exhibited by A-192621 and BQ788 are not a result of ETRA inhibition. Conclusion: While ETRB antagonists reduce the viability of glioma cells in vitro, it appears unlikely that this effect is mediated by ETRB inhibition or cross-reaction with ETRA. Instead, we present evidence that A-192621 affects glioma and melanoma viability by activating stress/DNA damage response pathways, which leads to cell cycle arrest and apoptosis. This is the first evidence linking ETRB antagonist treatment to enhanced expression of DNA damage-inducible genes