Enhancement of noncontact friction between closely spaced bodies by two-dimensional systems

. We consider the effect of an external bias voltage and the spatial variation of the surface potential, on the damping of cantilever vibrations. The electrostatic friction is due to energy losses in the sample created by the electromagnetic field from the oscillating charges induced on the surface of the tip by the bias voltage and spatial variation of the surface potential. A similar effect arises when the tip is oscillating in the electrostatic field created by charged defects in a dielectric substrate. The electrostatic friction is compared with the van der Waals friction originating from the fluctuating electromagnetic field due to quantum and thermal fluctuation of the current density inside the bodies. We show that the electrostatic and van der Waals friction can be greatly enhanced if on the surfaces of the sample and the tip there are two-dimension (2D) systems, e.g. a 2D-electron system or incommensurate layers of adsorbed ions exhibiting acoustic vibrations. We show that the damping of the cantilever vibrations due to the electrostatic friction may be of similar magnitude as the damping observed in recent experiments of Stipe \textit{et al} [B.C.Stipe, H.J.Mamin, T.D.Stowe, T.W.Kenny, and D.Rugar, Phys.Rev. Lett.% \textbf{87}, 0982001]. We also show that at short separation the van der Waals friction may be large enough to be measured experimentally.Comment: 11 pages, 2 figure

Standardization of Marine Meteorological Data from FINO Offshore Platforms

KlimawandelDer Ausbau der Offshore-Windenergie gehört zu den erklärten Zielen der Bundesregierung. Um bessere Ken ntnisse der Bedingungen auf See zu erlangen, wurden drei Forschungsplattformen in der Nordsee (FINO 1 und 3) und Ostsee (FINO 2) errichtet. An diesen werden meteorologische und ozeanographische Größen in unterschiedlichen Höhen gemessen, um unter anderem Aussagen zu Vertikalprofilen der Windgeschwindigkeit treffen zu können. Da sich die Plattformen und Masten im Design unterscheiden und sich insbesondere bei den Windmessungen deutlich ein richtungsabhängiger Einfluss auf die Messungen zeigt, ist für die Vergleichbarkeit der Standorte eine standardisierte Auswertung der Messergebnisse erforderlich. Ziel des Projektes FINO-Wind ist es, die Vergleichbarkeit der Daten der drei Standorte zu verbessern und den Datennutzern nach standardisierten Methoden qualitätsgeprüfte Daten zur Verfügung zu stellen. Es sollen deshalb Standardisierungsverfahren zur Auswertung der Winddaten entwickelt werden. Insbesondere die verschiedenen Masteffekte werden eingehend untersucht und durch Windkanalmessungen, Vergleich mit LiDAR-Daten, CFD (Computational Fluid Dynamics)-Modellierungen und Anwendung der UAM (Uniform ambient flow mast correction)-Methode abgeschätzt. Daraus werden Korrekturfaktoren für Windmessungen abgeleitet, die später angewendet werden sollen. Die Messdaten, die als 10-Minuten-Werte vorliegen, werden des Weiteren einer umfassenden und automatisierten Qualitätsprüfung unterzogen. Dabei durchlaufen die Daten in aufeinanderfolgenden Schritten formale, klimatologische, zeitliche, Wiederholungs- und Konsistenzprüfungen und werden nach erfolgreichem Abschluss jeder Sequenz mit spezifischen Qualitätsflags gekennzeichnet. Aus der Analyse und dem Vergleich der Instrumentierung in unterschiedlichen Höhen, der Installation und Ausrichtung sowie die Mastkonstruktionen sollen Empfehlungen herausgearbeitet werden, wie zukünftige Anwendungen im Bereich der Offshore-Windmessungen verbessert werden können

PENENTUAN KANDUNGAN TOTAL FLAVONOID DAN TOTAL FENOL DARI AKAR KERSEN (Mutingia calabura) SERTA AKTIVITASNYA SEBAGAI ANTIOKSIDAN

Penelitian ini bertujuan untuk mengetahui kadar fenol dan flavonoid total dari ekstrak akar kersen serta aktivitas antioksidannya. Hasil ekstraksi 1 kg akar kersen menghasilkan ekstrak etanol (30,56 g), kloroform (6,52 g), etilasetat (6,1 g), n-butanol (3,21 g) dan air (4,65 g). Penapisan fitokimia menunjukkan ekstrak yang positif flavonoid adalah ekstrak air, kloroform, etanol dan etil asetatsedangkankelimaekstrak tersebut positif mengandung polifenol.  Ekstrak etanol, n-butanol, kloroform, etil asetat, dan air memiliki kandungan total fenol berturut-turut yaitu 12,62%, 3,81%, 6,12%, 8,75%, dan 11,93%. Kandungan flavonoid pada ekstrak etanol, kloroform, etil asetat, dan air berturut-turut yaitu 0,22%, 0,05%, 0,12%, dan 0,03%. Aktivitas antioksidan pada ekstrak etanol diukur dengan metode DPPH dan dinyatakan dengan nilai IC50 sebesar 36,44 pp

Enzymatic Mechanisms Involved in Evasion of Fungi to the Oxidative Stress: Focus on Scedosporium apiospermum

The airways of patients with cystic fibrosis (CF) are frequently colonized by various filamentous fungi, mainly Aspergillus fumigatus and Scedosporium species. To establish within the respiratory tract and cause an infection, these opportunistic fungi express pathogenic factors allowing adherence to the host tissues, uptake of extracellular iron, or evasion to the host immune response. During the colonization process, inhaled conidia and the subsequent hyphae are exposed to reactive oxygen species (ROS) and reactive nitrogen species (RNS) released by phagocytic cells, which cause in the fungal cells an oxidative stress and a nitrosative stress, respectively. To cope with these constraints, fungal pathogens have developed various mechanisms that protect the fungus against ROS and RNS, including enzymatic antioxidant systems. In this review, we summarize the different works performed on ROS- and RNS-detoxifying enzymes in fungi commonly encountered in the airways of CF patients and highlight their role in pathogenesis of the airway colonization or respiratory infections. The potential of these enzymes as serodiagnostic tools is also emphasized. In addition, taking advantage of the recent availability of the whole genome sequence of S. apiospermum, we identified the various genes encoding ROS- and RNS-detoxifying enzymes, which pave the way for future investigations on the role of these enzymes in pathogenesis of these emerging species since they may constitute new therapeutics targets

The LeucoPatch® system in the management of hard-to-heal diabetic foot ulcers: study protocol for a randomised controlled trial

Background: Diabetic foot ulcers are a common and severe complication of diabetes mellitus. Standard treatment includes debridement, offloading, management of infection and revascularisation where appropriate, although healing times may be long. The LeucoPatch® device is used to generate an autologous platelet-rich fibrin and leucocyte wound dressing produced from the patient's own venous blood by centrifugation, but without the addition of any reagents. The final product comprises a thin, circular patch composed predominantly of fibrin together with living platelets and leucocytes. Promising results have been obtained in non-controlled studies this system, but this now needs to be tested in a randomised controlled trial (RCT). If confirmed, the LeucoPatch® may become an important new tool in the armamentarium in the management of diabetic foot ulcers which are hard-to-heal. Methods: People with diabetes and hard-to-heal ulcers of the foot will receive either pre-specified good standard care or good standard care supplemented by the application of the LeucoPatch® device. The primary outcome will be the percentage of ulcers healed within 20 weeks. Healing will be defined as complete epithelialisation without discharge that is maintained for 4 weeks and is confirmed by an observer blind to randomisation group. Discussion: Ulcers of the foot are a major source of morbidity to patients with diabetes and costs to health care economies. The study population is designed to be as inclusive as possible with the aim of maximising the external validity of any findings. The primary outcome measure is healing within 20 weeks of randomisation and the trial also includes a number of secondary outcome measures. Among these are rate of change in ulcer area as a predictor of the likelihood of eventual healing, minor and major amputation of the target limb, the incidence of infection and quality of life. Trial registration: International Standard Randomised Controlled Trial, ISRCTN27665670. Registered on 5 July 2013

Improving nutritional care quality in the orthopedic ward of a Septic Surgery Center by implementing a preventive nutritional policy using the Nutritional Risk Score: a pilot study.

Septic Surgery Center (SSC) patients are at a particularly high risk of protein-energy malnutrition (PEM), with a prevalence of 35-85% found in various studies. Previous collaboration between our hospital's SSC and its Clinical Nutrition Team (CNT) only focussed on patients with severe PEM. This study aimed to determine whether it was possible to improve the quality of nutritional care in septic surgery patients with help of a nutritional policy using the Nutritional Risk Score (NRS). Nutritional practices in the SSC were observed over three separate periods: in the 3 months leading up to the implementation baseline, 6 months after implementation of preventive nutritional practices, and at 3 years. The nutritional care quality indicator was the percentage of patients whose nutritional care, as prescribed by the SSC, was adapted to their specific requirements. We determined the septic surgery team's NRS completion rate and calculated the nutritional policy's impact on SSC length of stay. Data before (T <sub>0</sub> ) and after (T <sub>1</sub> + T <sub>2</sub> ) implementation of the nutritional policy were compared. Ninety-eight patients were included. The nutritional care-quality indicator improved from 26 to 81% between T <sub>0</sub> and T <sub>2</sub> . During the T <sub>1</sub> and T <sub>2</sub> audits, septic surgery nurses calculated NRS for 100% and 97% of patients, respectively. Excluding patients with severe PEM, SSC length of stay was significantly reduced by 23 days (p = 0.005). These findings showed that implementing a nutritional policy in an SSC is possible with the help of an algorithm including an easy-to-use tool like the NRS

Evaluation de l'état nutritionnel des sujets âgés porteurs d'ulcère(s) de jambe

LE KREMLIN-B.- PARIS 11-BU Méd (940432101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF