In Situ Laser Light Scattering for Temporally and Locally Resolved Studies on Nanoparticle Trapping in a Gas Aggregation Source

Gas phase synthesis of nanoparticles (NPs) via magnetron sputtering in a gas aggregation source (GAS) has become a well-established method since its conceptualization three decades ago. NP formation is commonly described in terms of nucleation, growth, and transport alongside the gas stream. However, the NP formation and transport involve complex non-equilibrium processes, which are still the subject of investigation. The development of in situ investigation techniques such as UV–Vis spectroscopy and small angle X-ray scattering enabled further insights into the dynamic processes inside the GAS and have recently revealed NP trapping at different distances from the magnetron source. The main drawback of these techniques is their limited spatial resolution. To understand the spatio-temporal behavior of NP trapping, an in situ laser light scattering technique is applied in this study. By this approach, silver NPs are made visible inside the GAS with good spatial and temporal resolution. It is found that the argon gas pressure, as well as different gas inlet configurations, have a strong impact on the trapping behavior of NPs inside the GAS. The different gas inlet configurations not only affect the trapping of NPs, but also the size distribution and deposition rate of NPs

Recurrent Fistula between Ileal Pouch and Vagina—Successful Treatment with a Gracilis Muscle Flap

Fistulae between an ileal pouch and the vagina are an uncommon complication of ileal pouch-anal anastomosis following proctocolectomy and mucosectomy in patients with familial adenomatous polyposis coli. Several reports describe the successful use of muscle flaps to close recurrent pouch-vaginal-fistulae (PVF). However, series only contain small numbers and an optimal management has not yet been determined. We report the case of a 26-year old woman with a third recurrence of a PVF after proctocolectomy for treatment of familial adenomatous polyposis in October 2005. Because local approaches failed, definitive closure of the fistula was achieved by interposition of a gracilis muscle flap between the pouch-anal anastomosis and the vagina. The postoperative course was uneventful; the patient was discharged 7 days after surgery and remained free of recurrence and symptomatic complaints for 22 months now. The gracilis muscle flap proved to be an effective method in the treatment of recurrent PVF

Ep-CAM expression in squamous cell carcinoma of the esophagus: a potential therapeutic target and prognostic marker

BACKGROUND: To evaluate the expression and test the clinical significance of the epithelial cellular adhesion molecule (Ep-CAM) in esophageal squamous cell carcinoma (SCC) to check the suitability of esophageal SCC patients for Ep-CAM directed targeted therapies. METHODS: The Ep-CAM expression was immunohistochemically investigated in 70 primary esophageal SCCs using the monoclonal antibody Ber-EP4. For the interpretation of the staining results, we used a standardized scoring system ranging from 0 to 3+. The survival analysis was calculated from 53 patients without distant metastasis, with R0 resection and at least 2 months of clinical follow-up. RESULTS: Ep-CAM neo-expression was observed in 79% of the tumors with three expression levels, 1+ (26%), 2+ (11%) and 3+ (41%). Heterogeneous expression was observed at all expression levels. Interestingly, tumors with 3+ Ep-CAM expression conferred a significantly decreased median relapse-free survival period (log rank, p = 0.0001) and median overall survival (log rank, p = 0.0003). Multivariate survival analysis disclosed Ep-CAM 3+ expression as independent prognostic factor. CONCLUSION: Our results suggest Ep-CAM as an attractive molecule for targeted therapy in esophageal SCC. Considering the discontenting results of the current adjuvant concepts for esophageal SCC patients, Ep-CAM might provide a promising target for an adjuvant immunotherapeutic intervention

Tunable polytetrafluoroethylene electret films with extraordinary charge stability synthesized by initiated chemical vapor deposition for organic electronics applications

Abstract Bulk polytetrafluoroethylene (PTFE) possesses excellent chemical stability and dielectric properties. Indeed, thin films with these same characteristics would be ideal for electret applications. Previously, the electret properties of PTFE-like thin films produced by rf sputtering or plasma enhanced chemical vapor deposition were found to deteriorate due to structural changes and surface oxidation. In this article, the technique of initiated chemical vapor deposition (iCVD) is evaluated for electret applications for the first time. The iCVD method is known for its solvent-free deposition of conformal, pinhole-free polymer thin films in mild process conditions. It is shown that PTFE thin films prepared in this way, show excellent agreement to commercial bulk PTFE with regard to chemical properties and dielectric dissipation factors. After ion irradiation in a corona discharge the iCVD PTFE thin films exhibit stable electret properties, which can be tailored by the process parameters. Due to the mild deposition conditions, the iCVD technique is suitable for deposition on flexible organic substrates for the next-generation electret devices. It is also compatible with state-of-the-art microelectronic processing lines due to the characteristics of conformal growth and easy scaling up to larger size substrates

In situ split plus portal vein ligation (ISLT) - a salvage procedure following inefficient portal vein embolization to gain adequate future liver remnant volume prior to extended liver resection.

BACKGROUND Right extended liver resection is frequently required to achieve tumor-free margins. Portal venous embolization (PVE) of the prospective resected hepatic segments for conditioning segments II/III does not always induce adequate hypertrophy in segments II and III (future liver remnant volume (FLRV)) for extended right-resection. Here, we present the technique of in situ split dissection along segments II/III plus portal disruption to segments IV-VIII (ISLT) as a salvage procedure to overcome inadequate gain of FLRV after PVE. METHODS In eight patients, FLRV was further pre-conditioned following failed PVE prior to hepatectomy (ISLT-group). We compared FLRV changes in the ISLT group with patients receiving extended right hepatectomy following sufficient PVE (PVEres-group). Survival of the ISLT-group was compared to PVEres patients and PVE patients with insufficient FLRV gain or tumor progress who did not receive further surgery (PVEnores-group). RESULTS Patient characteristics and surgical outcome were comparable in both groups. The mean FLRV-to-body-weight ratio in the ISLT group was smaller than in the PVEres-group pre- and post-PVE. One intraoperative mortality due to a coronary infarction was observed for an ISLT patient. ISLT was successfully completed in the remaining seven ISLT patients. Liver function and 2-year survival of ~ 50% was comparable to patients with extended right hepatectomy after efficient PVE. Patients who received a PVE but who were not subsequently resected (PVEnores) demonstrated no survival beyond 4 months. CONCLUSION Despite extended embolization of segments I and IV-VIII, ISLT should be considered if hypertrophy was not adequate. Liver function and overall survival after ISLT was comparable to patients with trisectionectomy after efficient PVE

A freestanding photoswitchable aero-polymer with an incorporated bridged azobenzene: 3D structure, photoinduced motion, biocompatibility and potential application as photomechanical cell scaffold

Photoswitchable polymers are of great interest for a variety of applications such as optical data storage, functional membranes and photoactuators. The latter are typically fabricated by wet-chemical approaches including gels, liquid-crystalline elastomers and supramolecular polymers. In this work we demonstrate the fabrication of a new freestanding photoswitchable aeropolymer-structure via solvent-free, single-step initiated chemical vapor deposition (iCVD) using tetrapodal zinc oxide (t-ZnO) as sacrificial substrate material. On the molecular scale, the copolymer is composed of 2-hydroxyethyl methacrylate (HEMA) and a specifically synthesized diazocine (a bridged azobenzene) as photoswitchable cross-linking unit. iCVD enables in this connection a combination of both comonomers while preserving their chemical functionalities as well as the individual structure of the t-ZnO templates without pore clogging. After post-reactional etching and drying, a hollow polymer network with nanoscopic thin walls remains maintaining the substrate characteristic tetrapodal structure, which we coined aero-photoswitch. We identify and differentiate specific properties of the fabricated structures, originating from the switchable copolymer and the highly porous tetrapodal conformation, for a comprehensive description of the overall aero-structures. These aero-photoswitchable polymers provide unique properties due to their extremely delicate yet stable morphology and their efficient transformation of molecular photoisomerization to motion on the macroscopic scale upon illumination with blue light. In addition, we investigate their biocompatibility as well as successful cell attachment and proliferation. These new photoswitchable actuators turn out to be highly promising smart materials for future research on photoswitchable scaffolds