Different response to epidermal growth factor of hepatocytes in cultures isolated from male or female rat liver. Inhibitor effect of estrogen on binding and mitogenic effect of epidermal growth factor

Deoxyribonucleic acid (DNA) synthesis in hepatocytes isolated from the livers of male and female rats has been compared in monolayer culture. Plating efficiency, DNA and protein content, viability, and morphologic appearance were the same in cultures prepared with hepatocytes isolated from male or female rats. Epidermal growth factor (EGF)-induced DNA synthesis was significantly higher in hepatocytes from male rats than in hepatocytes from female rats. This was the case whether hepatocytes were isolated from normal or partially hepatectomized male or female rats. Hepatocytes isolated from regenerating liver synthesize more DNA than those isolated from normal liver in response to EGF. This increased response to EGF in hepatocytes derived from regenerating liver was relatively the same for male- and female-derived hepatocytes, but the magnitude of the response was considerably higher in male-derived hepatocytes. In contrast, in vivo DNA synthesis in the liver remnant after partial hepatectomy was similar in male and female rats if measured 24 h after the operation. A comparison of EGF binding to male- and female-derived hepatocytes maintained in primary culture indicated a lower number of high-affinity receptors for EGF in the female hepatocytes. The addition of estrogen to primary cultures of hepatocytes isolated from male rats inhibited EGF binding as well as EGF-induced DNA synthesis. Our studies show significant differences in DNA synthesis in response to EGF when male and female hepatocytes are compared in primary culture. The regenerative response after partial hepatectomy, on the other hand, was the same in male and female rats. Thus, our studies indicate that the sex of the donor rat is important when hepatocytes in culture are used for a variety of studies, such as hepatocyte metabolism, induction and control of DNA synthesis, and hepatocarcinogenesis. In addition, our results indicate that caution is advised when inferences are made from in vitro findings for in vivo conditions. © 1987

Do Primary Care Doctors Behave the Same in Antibiotic Prescribing for Upper Respiratory Tract Infections?

Purpose: To compare the extent of using an evidence-based approach in managing upper respiratory tract infections (URTIs) among primary care doctors from two different government clinic settings in Malaysia. Method: This is a cross sectional, prospective study carried out in a teaching university primary care centre in Kuala Lumpur (KL) where doctors are constantly exposed to continuing medical education (CME) and seven health clinics in Seremban, Malaysia where doctors have less exposure to CME in the year 2000. Twelve primary care practitioners in KL and 13 in Seremban participated in the study. Each practitioner was asked to record clinical data and prescriptions given to twenty consecutive patients with URTIs using a structured questionnaire for each patient. The extent of usage of an evidence-based approach in managing URTIs among practitioners was assessed

Are Doctors in the University-Based Primary Care Clinic More Evidence-Based?

Letter to the editor

Developing and applying a user-centered model for the design and implementation of information visualization tools

The objective of this paper is to show how approaches for user-centered information visualization design and development are being applied in the context of healthcare where users are not familiar with information visualization techniques. We base our design methods on user-centered frameworks in which 'prototyping' plays an important role in the process. We modify existing approaches to involve prototyping at an early stage of the process as the problem domain is assessed. We believe this to be essential, as it increases users' awareness of what information visualization techniques can offer them and that it enables users to participate more effectively in later stages of the design and development process. This also acts as a stimulus for engagement. The problem domain analysis stage of a pilot study using this approach is presented, in which techniques are being collaboratively developed with domain users from a healthcare institution. Our results suggest that this approach has engaged users, who are subsequently able to apply generic information visualization concepts to their domains and as a result are better equipped to take part in the subsequent collaborative design and development process

Elevated Expression and Pro-Inflammatory Activity of IL-36 in Patients with Systemic Lupus Erythematosus

published_or_final_versio

Quantum interference and phonon-mediated back-action in lateral quantum dot circuits

Spin qubits have been successfully realized in electrostatically defined, lateral few-electron quantum dot circuits. Qubit readout typically involves spin to charge information conversion, followed by a charge measurement made using a nearby biased quantum point contact. It is critical to understand the back-action disturbances resulting from such a measurement approach. Previous studies have indicated that quantum point contact detectors emit phonons which are then absorbed by nearby qubits. We report here the observation of a pronounced back-action effect in multiple dot circuits where the absorption of detector-generated phonons is strongly modified by a quantum interference effect, and show that the phenomenon is well described by a theory incorporating both the quantum point contact and coherent phonon absorption. Our combined experimental and theoretical results suggest strategies to suppress back-action during the qubit readout procedure.Comment: 25 pages, 8 figure

The eyes of the deep diving hooded seal (Cystophora cristata) enhance sensitivity to ultraviolet light

The mammalian visual range is approximately 400-700nm, although recent evidence suggests varying ultraviolet (UV) extensions in diverse terrestrial species. UV sensitivity may have advantages in the dim, blue light shifted environment experienced by submerged marine mammals. It may also be advantageous when seals are hauled out as UV is reflected by snow and ice but absorbed by fur, enhancing visual contrast. Here we show that the pelagic hooded seal (Cystophora cristata) has a highly UV permissive cornea and lens. Seals like other carnivores have a tapetum lucidum (TL) reflecting light back through the retina increasing sensitivity. The TL in this seal is unusual being white and covering almost the entire retina unlike that in other carnivores. Spectral reflectance from its surface selectively increases the relative UV/blue components >10 times than other wavelengths. Retinal architecture is consistent with a high degree of convergence. Enhanced UV from a large TL surface with a high degree of retinal convergence will increase sensitivity at a cost to acuity. UV electrophysiological retina responses were only obtained to dim, rod mediated stimuli, with no evidence of cone input. As physiological measurements of threshold sensitivity are log units higher than those for psychophysical detection, these seals are likely to be more UV sensitive than our results imply. Hence, UV reflections from the TL will afford increased sensitivity in dim oceanic environments

A two dimensional nanopatterned thin metallic transparent conductor with high transparency from the ultraviolet to the infrared

Cataloged from PDF version of article.The optical properties of a two-dimensional nanohole patterned aluminum thin film in hexagonal lattice are studied. The transmission dip can be moved out from the visible range by manipulating the lattice constant. The resulting nanopatterned thin film is demonstrated to exhibit a high transparency in a wide wavelength range. The origins of the transmission dip and the transmission drop are explained. For constant resistance, thicker films with a larger filling ratio lead to better transmittance in the visible range. Angular response of the nanopatterned metallic film is also analyzed, and transmittances using several other metals are compared. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4765341

Development of a stochastic computational fluid dynamics approach for offshore wind farms

In this paper, a method for stochastic analysis of an offshore wind farm using computational fluid dynamics (CFD) is proposed. An existing offshore wind farm is modelled using a steady-state CFD solver at several deterministic input ranges and an approximation model is trained on the CFD results. The approximation model is then used in a Monte-Carlo analysis to build joint probability distributions for values of interest within the wind farm. The results are compared with real measurements obtained from the existing wind farm to quantify the accuracy of the predictions. It is shown that this method works well for the relatively simple problem considered in this study and has potential to be used in more complex situations where an existing analytical method is either insufficient or unable to make a good prediction