Recent advances in minimally invasive colorectal cancer surgery

Laparoscopy has improved surgical treatment of various diseases due to its limited surgical trauma and has developed as an interesting therapeutic alternative for the resection of colorectal cancer. Despite numerous clinical advantages (faster recovery, less pain, fewer wound and systemic complications, faster return to work) the laparoscopic approach to colorectal cancer therapy has also resulted in unusual complications, i.e. ureteral and bladder injury which are rarely observed with open laparotomy. Moreover, pneumothorax, cardiac arrhythmia, impaired venous return, venous thrombosis as well as peripheral nerve injury have been associated with the increased intraabdominal pressure as well as patient's positioning during surgery. Furthermore, undetected small bowel injury caused by the grasping or cauterizing instruments may occur with laparoscopic surgery. In contrast to procedures performed for nonmalignant conditions, the benefits of laparoscopic resection of colorectal cancer must be weighed against the potential for poorer long-term outcomes of cancer patients that still has not been completely ruled out. In laparoscopic colorectal cancer surgery, several important cancer control issues still are being evaluated, i.e. the extent of lymph node dissection, tumor implantation at port sites, adequacy of intraperitoneal staging as well as the distance between tumor site and resection margins. For the time being it can be assumed that there is no significant difference in lymph node harvest between laparoscopic and open colorectal cancer surgery if oncological principles of resection are followed. As far as the issue of port site recurrence is concerned, it appears to be less prevalent than first thought (range 0-2.5%), and the incidence apparently corresponds with wound recurrence rates observed after open procedures. Short-term (3-5 years) survival rates have been published by a number of investigators, and survival rates after laparoscopic surgery appears to compare well with data collected after conventional surgery for colorectal cancer. However, long-term results of prospective randomized trials are not available. The data published so far indicate that the oncological results of laparoscopic surgery compare well with the results of the conventional open approach. Nonetheless, the limited information available from prospective studies leads us to propose that minimally invasive surgery for colorectal cancer surgery should only be performed within prospective trials

Strain enhancement of superconductivity in CePd2Si2 under pressure

We report resistivity and calorimetric measurements on two single crystals of CePd2Si2 pressurized up to 7.4 GPa. A weak uniaxial stress induced in the pressure cell demonstrates the sensitivity of the physics to anisotropy. Stress applied along the c-axis extends the whole phase diagram to higher pressures and enhances the superconducting phase emerging around the magnetic instability, with a 40% increase of the maximum superconducting temperature, Tc, and a doubled pressure range. Calorimetric measurements demonstrate the bulk nature of the superconductivity.Comment: 4 pages, 4 figure

Quasifree pion photoproduction on the deuteron in the Δ\Delta region

Photo production of pions on the deuteron is studied in the spectator nucleon model. The Born terms of the elementary production amplitude are determined in pseudovector $\pi$N coupling and supplied with a form factor. The $\Delta$ resonance is considered both in the $s$ and the $u$ channel. The parameters of the $\Delta$ resonance and the cutoff of the form factors are fixed on the leading photoproduction multipoles. Results for total and differential cross sections are compared with experimental data. Particular attention is paid to the role of Pauli correlations of the final state nucleons in the quasifree case. The results are compared with those for pion photoproduction on the nucleon.Comment: 17 pages LateX2e including 5 postscript figure

Herzfrequenzvariabilität in der Postmenopause

Zusammenfassung: Autonomes Nervensystem und Herzfrequenzvariabilität: Sowohl eine Dysregulation des autonomen Nervensystems (ANS) als auch die Menopause sind mit einem erhöhten kardiovaskulären Risiko verbunden. Das kardiale ANS kann anhand der Herzfrequenzvariabilität (HRV) beurteilt und in Frequenzspektren aufgespalten werden, die sich dem Parasympathikus- und/oder Sympathikuseinfluss zuordnen lassen. Einfluss der endokrinen Lebensphasen: Bereits während des Menstruationszyklus zeigt sich eine zyklusabhängige Fluktuation der HRV. Mit dem menopausalen Östrogenabfall ist ein Anstieg des Sympathikotonus mit HRV-Reduktion verbunden, was mit einem erhöhten kardiovaskulären Risiko einhergeht. Das mit menopausalen Hitzewallungen verbundene erhöhte kardiovaskuläre Erkrankungsrisiko ist möglicherweise ebenso auf eine Sympathikusaktivierung zurückzuführen. Therapie: Eine Hormonersatztherapie vermag eventuell eine Wiederherstellung der autonomen Balance herbeizuführe

Teachers' notions about their communicative competencies

This article describes the results of four empirical research studies of teachers' notions about effective conduct in various pedagogical situations and about communicative competencies, which can help in resolving difficult pedagogical problems. The findings indicate that teachers' ideas concerning their professional conduct and communicative competencies are rather positive. The majority of teachers identify their conduct in difficult pedagogical situations with that of an "ideal" teacher. At the same time, the results received when the semantic differential was used revealed the ambiguous character of teachers' assessments of their own communicative competencies. Psychological training focused on deepening teachers' notions about communicative culture was carried out. As a result of the training, teachers' notions about their own communicative competencies changed. © Lomonosov Moscow State University, 2014

Assessment of the U and Co magnetic moments in UCoGe by X-ray magnetic circular dichroism

The ferromagnetic superconductor UCoGe has been investigated by high field X-ray magnetic circular dichroism (XMCD) at the U-M$_{4,5}$ and Co/Ge-K edges. The analysis of the branching ratio and XMCD at the U-M$_{4,5}$ edges reveals that the U-5$f$ electrons count is close to 3. The orbital ($\sim0.70\,\mu_B$) and spin ($\sim-0.30\,\mu_B$) moments of U at 2.1K and 17T (H//c) have been determined. Their ratio ($\sim-2.3$) suggests a significant delocalization of the 5$f$ electron states. The similar field dependences of the local U/Co and the macroscopic magnetization indicate that the Co moment is induced by the U moment. The XMCD at the Co/Ge-K edges reveal the presence of small Co-4$p$ and Ge-4$p$ orbital moments parallel to the macroscopic magnetization. In addition, the Co-3$d$ moment is estimated to be at most of the order of 0.1$\mu_B$ at 17T. Our results rule out the possibility of an unusual polarisability of the U and Co moments as well as their antiparallel coupling. We conclude that the magnetism which mediates the superconductivity in UCoGe is driven by U.Comment: 4 figures + supplementary materia

Quantum nondemolition-like, fast measurement scheme for a superconducting qubit

We present a measurement protocol for a flux qubit coupled to a dc-Superconducting QUantum Interference Device (SQUID), representative of any two-state system with a controllable coupling to an harmonic oscillator quadrature, which consists of two steps. First, the qubit state is imprinted onto the SQUID via a very short and strong interaction. We show that at the end of this step the qubit dephases completely, although the perturbation of the measured qubit observable during this step is weak. In the second step, information about the qubit is extracted by measuring the SQUID. This step can have arbitrarily long duration, since it no longer induces qubit errors.Comment: published version, minor correction

Kondo Effect in Multiple-Dot Systems

We study the Kondo effect in multiple-dot systems for which the inter- as well as intra-dot Coulomb repulsions are strong, and the inter-dot tunneling is small. The application of the Ward-Takahashi identity to the inter-dot dynamical susceptibility enables us to analytically calculate the conductance for a double-dot system by using the Bethe-ansatz exact solution of the SU(4) impurity Anderson model. It is clarified how the inter-dot Kondo effect enhances or suppresses the conductance under the control of the gate voltage and the magnetic field. We then extend our analysis to multiple-dot systems including more than two dots, and discuss their characteristic transport properties by taking a triple-dot system as an example.Comment: 8 pages, 9 figure

Crossover from weak to strong coupling regime in dispersive circuit QED

We study the decoherence of a superconducting qubit due to the dispersive coupling to a damped harmonic oscillator. We go beyond the weak qubit-oscillator coupling, which we associate with a phase Purcell effect, and enter into a strong coupling regime, with qualitatively different behavior of the dephasing rate. We identify and give a physicaly intuitive discussion of both decoherence mechanisms. Our results can be applied, with small adaptations, to a large variety of other physical systems, e. g. trapped ions and cavity QED, boosting theoretical and experimental decoherence studies.Comment: Published versio