Precise measurements of electron and hole g-factors of single quantum dots by using nuclear field

We demonstrated the cancellation of the external magnetic field by the nuclear field at one edge of the nuclear polarization bistability in single InAlAs quantum dots. The cancellation for the electron Zeeman splitting gives the precise value of the hole g-factor. By combining with the exciton g-factor that is obtained from the Zeeman splitting for linearly polarized excitation, the magnitude and sign of the electron and hole g-factors in the growth direction are evaluated.Comment: 3 pages, 2 figure

Duality with expanding maps and shrinking maps, and its applications to Gauss maps

We study expanding maps and shrinking maps of subvarieties of Grassmann varieties in arbitrary characteristic. The shrinking map was studied independently by Landsberg and Piontkowski in order to characterize Gauss images. To develop their method, we introduce the expanding map, which is a dual notion of the shrinking map and is a generalization of the Gauss map. Then we give a characterization of separable Gauss maps and their images, which yields results for the following topics: (1) Linearity of general fibers of separable Gauss maps; (2) Generalization of the characterization of Gauss images; (3) Duality on one-dimensional parameter spaces of linear subvarieties lying in developable varieties.Comment: 28 pages, v3: added some examples, v2: the title has been changed from v1 "Linearity of general fibers of separable Gauss maps

Axisymmetric polydimethysiloxane microchannels for in vitro hemodynamic studies

The current microdevices used for biomedical research are often manufactured using microelectromechanical systems (MEMS) technology. Although it is possible to fabricate precise and reproducible rectangular microchannels using soft lithography techniques, this kind of geometry may not reflect the actual physiology of the microcirculation. Here, we present a simple method to fabricate circular polydimethysiloxane (PDMS) microchannels aiming to mimic an in vivo microvascular environment and suitable for state-of-the-art microscale flow visualization techniques, such as confocal µPIV/PTV. By using a confocal µPTV system individual red blood cells (RBCs) were successfully tracked trough a 75 µm circular PDMS microchannel. The results show that RBC lateral dispersion increases with the volume fraction of RBCs in the solution, i.e. with the hematocrit

Chemical Effects on Kβ/Kα X-Ray Intensity Ratio for 97mTc and 95mTc

開始ページ、終了ページ: 冊子体のページ付

The Imprecision of Sonographic Assessment of Jugular Venous Distension Among Novice Operators

ObjectiveTo assess the precision of sonographic assessment of jugular venous distension (US-JVD).MethodsSixteen emergency physicians underwent a short training in US-JVD comparable to a previously described training module. Then, they each performed US-JVD on three healthy individuals: Participant 1 with a “long, thin neck,” Participant 2 with a “normal neck,” and Participant 3 with a “short, thick neck.” The criterion standard for US-JVD was the measurements by an expert sonographer who had previously performed 100 US-JVD exams.ResultsThere were a total of 48 US-JVD measurements. Twenty-five measurements were within 1 cmH2O of the criterion standard (52%). Ten out of 16 operators were within 1 cmH2O for Participant 1, as opposed to six of out 16 and nine of out 16 for Participants 2 and 3, respectively. The range of values was largest for Participant 2 (4-11 cmH2O) and smallest for Participant 3 (6-10 cmH2O). Five measurements (10%) were wrong, indicating abnormally low measurements consistent with hypovolemia.ConclusionPhysicians were the most precise while performing US-JVD on the participant with a “short, thick neck,” and the least precise in the participant with a “normal neck.” Ten percent of the measurements misidentified these healthy participants as having hypovolemia