Current Status of Intensified Neo-Adjuvant Systemic Therapy in Locally Advanced Rectal Cancer

The addition of 5-fluorouracil (5-FU) or its prodrug capecitabine to radiotherapy (RT) is a standard approach in the neo-adjuvant treatment of patients with rectal tumors extending beyond the muscularis propria (stage II) and/or with clinical evidence of regional lymph node metastases (stage III). According to European randomized trials, the combined treatment modality resulted in favorable local control rates as compared with radiotherapy (RT) alone, but no improvement was found regarding the occurrence of distant metastases or overall survival. In an effort to further enhance the response rates and to decrease the high incidence of distant metastases in locally advanced rectal cancer patients, the addition of other chemotherapeutical drugs and biologic agents as radiation sensitizers to neo-adjuvant 5-FU based chemoradiotherapy (CRT) has been recently investigated. The role of those agents is however questionable as first results from phase III data do not show improvement on pathologic complete remission and circumferential resection margin negative resection rates as compared to 5-FU based CRT, nevertheless an increased toxicity

Oxidation, Coordination, and Nickel-Mediated Deconstruction of a Highly Electron-Rich Diboron Analogue of 1,3,5-Hexatriene

The reductive coupling of an N-heterocyclic carbene (NHC) stabilized (dibromo)vinylborane yields a 1,2-divinyldiborene, which, although isoelectronic to a 1,3,5-triene, displays no extended π conjugation because of twisting of the C2B2C2 chain. While this divinyldiborene coordinates to copper(I) and platinum(0) in an η2-B2 and η4-C2B2 fashion, respectively, it undergoes a complex rearrangement to an η4-1,3-diborete upon complexation with nickel(0)

Phase II study of helical tomotherapy in the multidisciplinary treatment of oligometastatic colorectal cancer

<p>Abstract</p> <p>Background</p> <p>Complete metastasectomy provides a real chance for long-term survival in patients with oligometastatic colorectal cancer (CRC). For inoperable patients, we evaluated in this study intensity-modulated and image-guided radiotherapy (IMRT-IGRT) by helical tomotherapy.</p> <p>Methods</p> <p>Twenty-four CRC patients with ≤ 5 metastases were enrolled, receiving a dose of 50 Gy in fractions of 5 Gy. No limitations concerning dimension or localization of the metastases were imposed. Whole body PET-CT was performed at baseline and 3 months after the initiation of RT to evaluate the metabolic response rate according to PET Response Criteria in Solid Tumors (PERCIST) version 1.0.</p> <p>Results</p> <p>A total of 53 metastases were treated. Seventeen patients (71%) received previously ≥ 1 line of chemotherapy for metastatic disease, displaying residual (n = 7) or progressive (n = 10) metabolic active oligometastatic disease at time of inclusion. Most common sites were the lung, liver and lymphnodes. One patient (4%) experienced grade 3 dysphagia. Twenty-two patients were evaluated by post-treatment PET-CT. Twelve patients achieved a complete (n = 6) or partial (n = 6) metabolic response, resulting in an overall metabolic response rate of 55%. At a median follow-up of 10 months, 7 patients (29%) are in remission, of which 5 received previous chemotherapy with residual oligometastatic disease at time of inclusion. The actuarial 1-year local control, progression-free survival, and overall survival were 54%, 14% and 78%.</p> <p>Conclusions</p> <p>Helical tomotherapy delivering 10 fractions of 5 Gy resulted in a metabolic response rate of 55%, and appeared to be attractive as consolidation of inoperable oligometastatic disease after effective chemotherapy.</p> <p>Trial registration</p> <p>Eudract 2008-008300-40; <a href="http://www.clinicaltrials.gov/ct2/show/NCT00807313">NCT00807313</a></p

Ab initio Berechnung der (110) Oberfläche von III - V Halbleitern : Simulation von Rastertunnelmikroskopieaufnahmen

Verbindungshalbleiter sind vor allem wegen ihrer Verwendbarkeit in optoelektronischen Bauelementen von besonderem technologischen Interesse. Voraussetzung ftlr Herstellung und zielgerichtetes Design elektronischer Bauelemente ist ein genaues Verstandnis der atomaren und elektronischen Struktur von Halbleiter-Schichtsystemen und Oberflachen. Eines der wichtigsten experimentellen Werkzeuge fiir die Untersuchung von Oberflachen ist die Rastertunnelmikroskopie (RTM). Obwohl die RTM auf einzigartige Weise eine Abbildung der elektronischen Oberflachenstruktur mit atomarer Aufldsung ermoglicht, so kann sie doch dieatomare Oberflachengeometrie nicht immer direkt und zweifelsfrei klaren. Die hierzu fehlende Verbindung zwischen elektronischer Struktur (lokale Zustandsdichte) und atomarer Geometrie (Atompositionen) kann durch "ab initio"-Rechnungen hergestellt werde

Ab-initio-Berechnung der (110)-Oberfläche von III-V-Halbleitern : Simulation von Rastertunnelmikroskopie-Aufnahmen

Verbindungshalbleiter sind vor allem wegen ihrer Verwendbarkeit in optoelektronischen Bauelementen von besonderem technologischen Interesse. Voraussetzung ftlr Herstellung und zielgerichtetes Design elektronischer Bauelemente ist ein genaues Verstandnis der atomaren und elektronischen Struktur von Halbleiter-Schichtsystemen und Oberflachen. Eines der wichtigsten experimentellen Werkzeuge fiir die Untersuchung von Oberflachen ist die Rastertunnelmikroskopie (RTM). Obwohl die RTM auf einzigartige Weise eine Abbildung der elektronischen Oberflachenstruktur mit atomarer Aufldsung ermoglicht, so kann sie doch dieatomare Oberflachengeometrie nicht immer direkt und zweifelsfrei klaren. Die hierzu fehlende Verbindung zwischen elektronischer Struktur (lokale Zustandsdichte) und atomarer Geometrie (Atompositionen) kann durch "ab initio"-Rechnungen hergestellt werde