On the Unified Theory for Non-Equilibrium Phenomena in the Isotropic and Nematic Phases of a Liquid Crystal; Spatially Inhomogeneous Alignment

A nonlinear equation is derived which describes the relaxation of the alignment and the flow alignment in the isotropic and nematic phases of a liquid crystal. In addition to the previously treated case, contributions associated with spatial derivatives of the alignment are taken into account which stem from gradient terms occuring in the free energy (elastic energy) and from the flux of the alignment. Some applications are discussed. In particular, the Leslie and Frank coefficients of the nematic phase are expressed in terms of the equilibrium alignment order parameter and coefficients which are meaningful in both phases

Electron- and proton-impact excitation of hydrogenlike uranium in relativistic collisions

The K shell excitation of H-like uranium (U(91+)) in relativistic collisions with different gaseous targets has been studied at the experimental storage ring at GSI Darmstadt. By performing measurements with different targets as well as with different collision energies, we were able to observe for the first time the effect of electron-impact excitation (EIE) process in the heaviest hydrogenlike ion. The large fine-structure splitting in H-like uranium allowed us to unambiguously resolve excitation into different L shell levels. State-of-the-art calculations performed within the relativistic framework which include excitation mechanisms due to both protons (nucleus) and electrons are in good agreement with the experimental findings. Moreover, our experimental data clearly demonstrate the importance of including the generalized Breit interaction in the treatment of the EIE process.

Dynamic Properties of Surfactants: Influence on Processes and Technologies

Industrial processes become faster and faster. The corresponding formulations have to keep pace with new technical solutions like spray coating in paper production or the substitution of isopropanol in fountain solutions for offset printing. Fast diffusion of amphiphiles to interfaces and the formation of interfacial films to lower the interfacial energy are the fundamental molecular mechanisms which have to be optimised for all high speed spraying and wetting processes. Our results show that the interfacial tension at water/air and at water/solid interfaces primarily depends on the concentration of free surfactants. Micelles act as depots for free surfactants which adjust the concentration in solution as soon as surfactants disappear by interface adsorption. By using synergistic mixtures it is possible to extend the application range of dynamic surfactants towards detergency by combining fast adsorption at interfaces with micellar properties.

Interfacial Tensions, Partition Coefficients, and Interfacial Elasticities: Measures for Emulsion Stability?

In this study the interfacial as well as the surface tensions, the partition coefficients Kp, the interfacial elasticities, and the stabilities of o/w-emulsions of the same systems were measured and compared to find a quantitative correlation which can help to control the emulsion stability. The systems in question contain water, paraffin oil and one of four non-ionic technical surfactants commonly used as emulsifiers. While a clear correlation between emulsion stability and equilibrium interfacial tension was found, the different emulsifying capacities cannot be explained by the partition coefficients Kp or the surface tension. However, combining the Kp results with the surface tension data allows us to estimate which emulsifier is more effective in solubilising a given amount of dispersed phase. Another method to classify emulsifiers is to carry out interfacial rheology measurements over a frequency range as broad as possible. Again a clear correlation between interfacial rheology and emulsifying capacity was found. This correlation, however, was restricted to surfactants of the same class. No correlation between interfacial rheology and emulsifying capacity could be found for emulsifiers of different molecular structure.

Low recurrence rate and low chronic pain associated with inguinal hernia repair by laparoscopic placement of Parietex ProGrip™ mesh: clinical outcomes of 220 hernias with mean follow-up at 23 months

INTRODUCTION

The aim of this study was to demonstrate the safety and the efficacy of the self-gripping Parietex ProGrip™ mesh (Sofradim Production, Trévoux, France) used with the laparoscopic approach for inguinal hernia repair. The incidence of chronic pain, post-operative complications, patient satisfaction and hernia recurrence at follow-up after 12 months was evaluated.

METHODS

Data were collected retrospectively from patient files and were analyzed for 169 male and female patients with 220 primary inguinal hernias. All patients included had undergone surgical repair for inguinal hernia by the laparoscopic transabdominal preperitoneal approach using Parietex ProGrip™ meshes performed in the same clinical center in Germany. Pre-, per- and post-operative data were collected, and a follow-up after 12 months was performed prospectively. Complications, pain scored on a 0-10 numeric rating scale (NRS), patient satisfaction and hernia recurrence were assessed.

RESULTS

The only complications were minor and were post-operative: hematoma/seroma (3 cases), secondary hemorrhage through the trocar's site (2 cases), hematuria, emphysema in the inguinal regions (both sides) and swelling above the genital organs (1 case for each). At mean follow-up at 22.8 months, there were only 3 reports of hernia recurrence: 1.4 % of the hernias. Most patients (95.9 %) were satisfied or very satisfied with their hernia repair with only 1.2 % reporting severe pain (NRS score 7-10) and 3.6 % reported mild pain.

CONCLUSION

This study demonstrates that in experienced hands, inguinal hernia repair surgery performed by laparoscopic transabdominal preperitoneal hernioplasty using Parietex ProGrip™ self-gripping meshes is rapid, efficient and safe with low pain and low hernia recurrence rate.

Polarization transfer of bremsstrahlung arising from spin-polarized electrons

We report on a study of the polarization transfer between transversely polarized incident electrons and the emitted x rays for electron-atom bremsstrahlung. By means of Compton polarimetry we performed for the first time an energy-differential measurement of the complete properties of bremsstrahlung emission related to linear polarization, i.e., the degree of linear polarization as well as the orientation of the polarization axis. For the high-energy end of the bremsstrahlung continuum the experimental results for both observables show a high sensitivity on the initial electron spin polarization and prove that the polarization orientation is virtually independent of the photon energy.

EGFR gene copy number increase in vulvar carcinomas is linked with poor clinical outcome

EGFR copy number increases have been frequently reported in cancer including vulvar carcinomas. Co-amplification of cancer genes plays an important role in the development of many tumour types. To better understand the effect of EGFR aberrations on vulvar cancer phenotype and patient prognosis, the authors analysed EGFR copy number changes using fluorescence in situ hybridisation and EGFR expression by immunohistochemistry in a tissue microarray containing 183 squamous cell carcinomas of vulva. Furthermore, the authors analysed the co-amplification frequency of EGFR with HER2, CCND1, MYC and PIK3CA, respectively. EGFR copy number increase was found in 39.3% of the tumours. Seventeen per cent of vulvar carcinomas showed EGFR high polysomy including 9% with amplification of the EGFR gene. Copy number gain of the EGFR locus was associated with non-basaloid phenotype (p=0.03), high-tumour stage (p<0.001), human papillomaviruse negativity of tumours (p=0.04) and the number of lymph node metastases (p=0.02). EGFR protein expression was statistically correlated to EGFR copy number increase (p<0.05). The observed co-amplification rate of EGFR with all four additionally examined oncogenes was much higher than statistically expected. There was a highly significant association between EGFR copy number increase and CCND1 amplifications (p<0.001) as well as the total number of gene amplifications (p=0.04). EGFR copy number gains were significantly related to unfavourable patient outcome in univariate analysis and multivariate Cox regression analysis. In conclusion, EGFR copy number increases are detectable in a substantial proportion of vulvar carcinomas with relationships to advanced tumour stages and the development of lymph node metastases. EGFR copy number aberrations are connected to other gene amplifications and probably define an human papillomaviruses-independent pathway in the development of vulvar carcinomas. These data support the potential utility of EGFR inhibitors as a therapeutic alternative in a subset of vulvar carcinomas.

Direct determination of the magnetic quadrupole contribution to the Lyman-α₁ transition in a hydrogenlike ion

We report the observation of an interference between the electric dipole (E1) and the magnetic quadrupole (M2) amplitudes for the linear polarization of the Ly-α1 (2p3/2→1s1/2) radiation of hydrogenlike uranium. This multipole mixing arises from the coupling of the ion to different multipole components of the radiation field. Our observation indicates a significant depolarization of the Ly-α1 radiation due to the E1-M2 amplitude mixing. It proves that a combined measurement of the linear polarization and of the angular distribution enables a very precise determination of the ratio of the E1 and the M2 transition amplitudes and the corresponding transition rates without any assumptions concerning the population mechanism for the 2p3/2 state.

Spectral shape of the two-photon decay of the 2 1S0 state in he-like tin

The spectral distribution of the 1s2s {1}S{0}-->1s{2} 1S0 two-photon decay of He-like tin was measured using a novel approach at the gas-jet target of the ESR storage ring. Relativistic collisions of Li-like projectiles with low-density gaseous matter have been exploited to selectively populate the desired 1s2s state. Compared to conventional techniques, this approach results in a substantial gain in statistical and systematic accuracy, which allowed us to achieve for the first time a sensitivity to relativistic effects on the two-photon decay spectral shape as well as to discriminate the measured spectrum for Sn from theoretical shapes for different elements along the He-isoelectronic sequence.

NF-kappaB activity in endothelial cells is modulated by cell substratum interactions and influences chemokine-mediated adhesion of natural killer cells

Because changes in subendothelial matrix composition are associated with alterations of the endothelial immune phenotype, we sought to understand if cytokine-induced NF-kappaB activity and downstream effects depend on substrate adherence of endothelial cells (EC). We compared the upstream phosphorylation cascade, activation of NF-kappaB, and expression/secretion of downstream effects of EC grown on tissue culture polystyrene plates (TCPS) with EC embedded within collagen-based matrices (MEEC). Adhesion of natural killer (NK) cells was quantified in vitro and in vivo. NF-kappaB subunit p65 nuclear levels were significantly lower and p50 significantly higher in cytokine-stimulated MEEC than in EC-TCPS. Despite similar surface expression of TNF-alpha receptors, MEEC had significantly decreased secretion and expression of IL-6, IL-8, MCP-1, VCAM-1, and ICAM-1. Attenuated fractalkine expression and secretion in MEEC (two to threefold lower than in EC-TCPS; p < 0.0002) correlated with 3.7-fold lower NK cell adhesion to EC (6,335 +/- 420 vs. 1,735 +/- 135 cpm; p < 0.0002). Furthermore, NK cell infiltration into sites of EC implantation in vivo was significantly reduced when EC were embedded within matrix. Matrix embedding enables control of EC substratum interaction. This in turn regulates chemokine and surface molecule expression and secretion, in particular of those compounds within NF-kappaB pathways, chemoattraction of NK cells, local inflammation, and tissue repair.

Performance of a Ge-microstrip imaging detector and polarimeter

Using 98% linearly polarized radiation at the European Synchrotron Radiation Facility in Grenoble, the performance of a prototype two-dimensional microstrip Ge(i) detector for x-ray imaging and as a Compton polarimeter has been evaluated. Using the energy and position sensitivity of the detector, the ability to obtain a complete reconstruction of the Compton event has been demonstrated. The modulation coefficient of the polarimeter is in good agreement with the theoretical limit of a perfect detector.

A delayed diagnosis of an unstable os odontoideum

We report the case of a 2-year old child from Kuwait with known history of tetraparesis from birth. Radiological evaluation including computed tomographic scan and magnetic resonance imaging confirmed an unstable orthotopic os odontoideum which was complicated by cervical myelopathy.

The effect of three-dimensional matrix-embedding of endothelial cells on the humoral and cellular immune response

The endothelium is a unique immunologic target. The first host-donor reaction in any cell, tissue or organ transplant occurs at the blood-tissue interface, the endothelium. When endothelial cells are themselves the primary component of the implant a second set of immunologic reactions arises. Injections of free endothelial cell implants elicit a profound major histocompatibility complex (MHC) II dominated immune response with significant sensitivity, cascade enhancement and immune memory. Endothelial cells embedded within three-dimensional matrices retain all the biosecretory capacity of quiescent endothelial cells. Perivascular implants of such cells are the most potent inhibitor of intimal hyperplasia and thrombosis following controlled vascular injury, but without any immune reactivity. Allo- and even xenogeneic endothelial cells evoke no significant humoral or cellular immune response in immunocompetent hosts when embedded within matrices. Moreover, endothelial implants are immunomodulatory, reducing the extent of the memory response to previous free cell implants. Attenuated immunogenicity results in muted activation of adaptive and innate immune cells. These findings point toward a pivotal role of matrix-cell-interconnectivity for the cellular immune phenotype and might therefore assist in the design of extracellular matrix components for successful tissue engineering.

Backbone cyclic peptidomimetic melanocortin-4 receptor agonist as a novel orally administrated drug lead for treating obesity

The tetrapeptide sequence His-Phe-Arg-Trp, derived from melanocyte-stimulating hormone (alphaMSH) and its analogs, causes a decrease in food intake and elevates energy utilization upon binding to the melanocortin-4 receptor (MC4R). To utilize this sequence as an effective agent for treating obesity, we improved its metabolic stability and intestinal permeability by synthesizing a library of backbone cyclic peptidomimetic derivatives. One analog, peptide 1 (BL3020-1), was selected according to its selectivity in activating the MC4R, its favorable transcellular penetration through enterocytes and its enhanced intestinal metabolic stability. This peptide was detected in the brain following oral administration to rats. A single oral dose of 0.5 mg/kg in mice led to reduced food consumption (up to 48% vs the control group) that lasted for 5 h. Repetitive once daily oral dosing (0.5 mg/kg/day) for 12 days reduced weight gain. Backbone cyclization was shown to produce a potential drug lead for treating obesity.