Irreversible inactivation of interleukin 2 in a pump-based delivery environment.

The physical stability of pharmaceutical proteins in delivery environments is a critical determinant of biological potency and treatment efficacy, and yet it is often taken for granted. We studied both the bioactivity and physical stability of interleukin 2 upon delivery via continuous infusion. We found that the biological activity of the delivered protein was dramatically reduced by approximately 90% after a 24-hr infusion program. Only a portion of these losses could be attributed to direct protein deposition on the delivery surfaces. Analysis of delivered protein by size exclusion chromatography gave no indication of insulin-like, surface-induced aggregation phenomena. Examination of the secondary and tertiary structure of both adsorbed and delivered protein via Fourier-transform infrared spectroscopy, circular dichroism, and fluorescence spectroscopy indicated that transient surface association of interleukin 2 with the catheter tubing resulted in profound, irreversible structural changes that were responsible for the majority of the biological activity losses.

Efflux pump of the proton antiporter family confers low-level fluoroquinolone resistance in Mycobacterium smegmatis.

Due to the resurgence of tuberculosis and the emergence of multidrug-resistant strains, fluoroquinolones (FQ) are being used in selected tuberculosis patients, but FQ-resistant strains of Mycobacterium tuberculosis have rapidly begun to appear. The mechanisms involved in FQ resistance need to be elucidated if the effectiveness of this class of antibiotics is to be improved and prolonged. By using the rapid-growing Mycobacterium smegmatis as a model genetic system, a gene was selected that confers low-level FQ resistance when present on a multicopy plasmid. This gene, lfrA, encodes a putative membrane efflux pump of the major facilitator family, which appears to recognize the hydrophilic FQ, ethidium bromide, acridine, and some quaternary ammonium compounds. It is homologous to qacA from Staphylococcus aureus, tcmA, of Streptomyces glaucescens, and actII and mmr, both from Streptomyces coelicoler. Increased expression of lfrA augments the appearance of subsequent mutations to higher-level FQ resistance.

The photoreceptor sensory rhodopsin I as a two-photon-driven proton pump.

Proton translocation experiments with intact cells of Halobacterium salinarium overproducing sensory rhodopsin I (SRI) revealed transport activity of SRI in a two-photon process. The vectoriality of proton translocation depends on pH, being outwardly directed above, and inwardly directed below, pH 5.7. Activation of the transport cycle requires excitation of the initial dark state of SRI, SRI590, to form the intermediate SRI380. Action spectra identify the photocycle intermediates SRI380 and SRI520 as the two photochemically reactive species in the outwardly directed transport process. As shown by flash photolysis experiments, SRI520 undergoes a so-far unknown photochemical reaction to SRI380 with a half-time of <200 micros. Mutation of SRI residue Asp-76, the residue which is equivalent to the proton acceptor Asp-85 in bacteriorhodopsin, to asparagine leads to inactivation of proton translocation. This demonstrates that the underlying mechanisms of proton transport in both retinal proteins share similar features. However, SRI is to our knowledge the first case where photochemical reactions between two thermally unstable photoproducts of a retinal protein constitute a catalytic ion transport cycle.

Examining the University of Denver's Family Friendly Benefits Plans: A look at Creating More Family Friendly Benefits to Drive Employee Retention

In the latter half of the twentieth century the workforce dynamic changed when the number of women entering the workforce increased by record amounts. In direct opposition to this change was the inability of organizations to meet the needs of employees with childcare concerns. Organizations and employees alike are best served when policies, procedures, and benefits are implemented to achieve a positive work/life balance. Companies that institute benefits that are supportive to families observe decreases in turnover and increased employee retention. Employees who are offered family friendly resources have been known to stay with companies even when offered a higher salary elsewhere. Demonstrating that retention of valued employees is linked to an organizations ability to offer support for family needs.

Fuzzy control of a water pump for an agricultural plant growth system

At the present time there is a high pressure toward the improvement of all the production processes. Those improvements can be sensed in several directions in particular those that involve energy efficiency. The definition of tight energy efficiency improvement policies is transversal to several operational areas ranging from industry to public services. As can be expected, agricultural processes are not immune to this tendency. This statement takes more severe contours when dealing with indoor productions where it is required to artificially control the climate inside the building or a partial growing zone. Regarding the latter, this paper presents an innovative system that improves energy efficiency of a trees growing platform. This new system requires the control of both a water pump and a gas heating system based on information provided by an array of sensors. In order to do this, a multi-input, multi-output regulator was implemented by means of a Fuzzy logic control strategy. Presented results show that it is possible to simultaneously keep track of the desired growing temperature set-point while maintaining actuators stress within an acceptable range.

Konventionelle Laparoskopie versus Handheld Roboter: eine Pelvitrainer Studie zum objektiven und subjektiven Vergleich des Terumo© Kymerax© Precision-Drive Articulating Surgical System mit konventionellen laparoskopischen Instrumenten

EINLEITUNG Anhand eines Pelvitrainer Modells wurde ein sogenannter „Handheld Roboter“ (Kymerax© Precision- Drive Articulating Surgical System von Terumo©) mit konventionellen laparoskopischen Instrumenten verglichen. Das Kymerax© System verfügt über eine Instrumentenspitze, welche durch Knöpfe am Handgriff zusätzlich abgewinkelt und rotiert werden kann. METHODE 45 Probanden wurden in 2 Erfahrungsgruppen aufgeteilt: 20 ExpertInnen (mehr als 50 selbstständig durchgeführte laparoskopische Operationen pro Jahr) und 25 StudentInnen (keine Erfahrung in der Laparoskopie). Sie führten 6 standardisierte Übungen durch, wobei die ersten beiden Übungen jeweils nur der Instrumenteninstruktion dienten und nicht ausgewertet wurden. In den restlichen 4 Übungen wurden Zeit, Fehleranzahl und Präzision erfasst. Es wurde in 2 Gruppen randomisiert. Eine Gruppe führte die Übungen zuerst mit dem konventionellen System und dann mit dem Kymerax© System durch. Bei der anderen Gruppe erfolgten die Übungen in umgekehrter Reihenfolge. Am Ende beantworteten die Teilnehmer Fragen zu den Übungen und den Operationssystemen. Die Daten wurden mittels Varianzanalyse ausgewertet. RESULTATE In allen 4 gemessenen Übungen brauchten die Probanden mit Kymerax© signifikant mehr Zeit (20%-40%). Vorteile des Kymerax© Systems waren eine bessere Nadelkontrolle bei einer auf den Operateur gerichteten Stichrichtung, eine geringere Abweichung beim Schneiden einer graden Linie, sowie ein geringeres Ausfransen der Schnittlinie beim graden wie beim runden Schneiden. Im Gegensatz zu den Experten kamen Studenten, welche das Kymerax© System in der zweiten Runde verwendeten, besser mit diesem zu Recht, als Ihre Studentenkollegen, die das Kymerax© System in der ersten Runde verwendeten. In der Befragung gaben über 90% der Teilnehmer an, dass das Kymerax© System bei der Durchführung der Übungen einen Vorteil bringt. Die Probanden empfanden jedoch die Bedienung als gewöhnungsbedürftig und erschöpften mit dem Kymerax© System schneller. Bemängelt wurde beim Kymerax© System die nicht freie Rotation, die eingeschränkte Abwinklung, die Sichteinschränkung durch den 7mm Schaft sowie die Ergonomie des Handgriffs. DISKUSSION Das Kymerax© System bringt Vorteile bei gewissen komplexen laparoskopischen Aufgaben. Der Preis hierfür ist die langsamere Durchführung der Aufgaben, die längere Angewöhnungszeit an das Instrument sowie die schnellere Ermüdung des Benutzers. Das System zeigt ein grosses Potential für die laparoskopische Chirurgie, jedoch sind weitere Verbesserungen notwendig. Von der Firma Terumo© wurde zwischenzeitlich das Operationssystem vom Markt genommen.

Algorithm for Estimation of Electricity Consumption Reduction by Using Variable Frequency Drive of Main Line Pumps

The article is about using of variable frequency drives for reduction oil pumping main line pumps energy consumption. Block diagram of developed computer program is shown in the article. The computer program allows to determine the reduction of energy consumption and to estimate payback period of variable frequency drives.