Chemoenzymatic Synthesis of Globo-series Glycosphingolipids and Evaluation of Their Immunosuppressive Activities.

Glycosphingolipids (GSLs) play essential roles in many important biological processes, making them attractive synthetic targets. In this paper, a viable chemoenzymatic method is described for the synthesis of globo-series GSLs, namely, Gb4, Gb5, SSEA-4, and Globo H. The strategy uses a chemically synthesized lactoside acceptor equipped with a partial ceramide structure that is uniquely extended by glycosyltransferases in a highly efficient one-pot multiple enzyme (OPME) procedure. A direct and quantitative conversion of Gb4 sphingosine to Globo H sphingosine is achieved by performing two-sequential OPME glycosylations. A reduction and N-acylation protocol allows facile incorporation of various fatty acids into the lipid portions of the GSLs. The chemically well-defined lipid-modified Globo H-GSLs displayed some differences in their immunosuppressive activities, which may benefit the structural modifications of Globo H ceramides in finding new types of immunosuppressive agents. The strategy outlined in this work should be applicable to the rapid access to other complex GSLs.

Design of a high-efficiency train headlamp with low power consumption using dual half-parabolic aluminized reflectors.

We propose a train headlamp system using dual half-circular parabolic aluminized reflectors. Each half-circular reflector contains five high-efficiency and small-package light-emitting diode (LED) chips, and the halves are 180° rotationally symmetric. For traffic safety, the headlamp satisfies the Code of Federal Regulations. To predict the pattern of illumination, an analytical derivation is developed for the optical path of a ray that is perpendicular to and emitted from the center of an LED chip. This ray represents the main ray emitted from the LED chip and is located at the maximum illuminance of the spot projected by the LED source onto a screen. We then analyze the design systematically to determine the locations of the LED chips in the reflector that minimize electricity consumption while satisfying reliability constraints associated with traffic safety. Compared to a typical train headlamp system with an incandescent or halogen lamp needing several hundred watts, the proposed system only uses 20.18 W to achieve the luminous intensity requirements.

Wide-angle and ultrathin camera module using a curved hexagonal microlens array and all spherical surfaces.

In this paper, we propose a wide-angle and thin camera module integrating the principles of an insect's compound eye and the human eye, mimicking them with a curved hexagonal microlens array and a hemispherical lens, respectively. Compared to typical mobile phone cameras with more than four lenses and a limited full field of view (FFOV), the proposed system uses only two lenses to achieve a wide FFOV. Furthermore, the thickness of our proposed system is only 2.7 mm. It has an f-number of 2.07, an image diameter of 4.032 mm, and a diagonal FFOV of 136°. The results showed good image quality with a modulation transfer function above 0.3 at a Nyquist frequency of 166 cycles/mm.

Wide-angle camera with multichannel architecture using microlenses on a curved surface.

We propose a multichannel imaging system that combines the principles of an insect's compound eye and the human eye. The optical system enables a reduction in track length of the imaging device to achieve miniaturization. The multichannel structure is achieved by a curved microlens array, and a Hypergon lens is used as the main lens to simulate the human eye, achieving large field of view (FOV). With this architecture, each microlens of the array transmits a segment of the overall FOV. The partial images are recorded in separate channels and stitched together to form the final image of the whole FOV by image processing. The design is 2.7 mm thick, with 59 channels; the 100°×80° full FOV is optimized using ZEMAX ray-tracing software on an image plane. The image plane size is 4.53 mm×3.29 mm. Given the recent progress in the fabrication of microlenses, this image system has the potential to be commercialized in the near future.