[Traditional Chinese medicine preparations in medical institutions: current situation and inspirations on research and development of new traditional Chinese medicine preparations].

Traditional Chinese medicine(TCM) preparations in medical institutions embody the characteristics of TCM and are the source for the development of new TCM drugs. This study summarizes the current situation, existing problems, and development trends of the TCM preparations in medical institutions in 31 provinces across China. Furthermore, this paper puts forward the development path of new TCM preparations based on the requirements of registration and management regulations of TCM preparations, providing new ideas for promoting the inheritance, innovation, and development of TCM.

Development of a compact high-current repetitive pulsed x-ray system.

Pulsed x-rays are crucial for various applications such as radiography, biological effects, and the system-generated electromagnetic pulse effect. X rays with a higher dose rate and a higher total dose can generate more significant radiation effects and more effective radiography. However, most pulsed sub-100 keV x-ray systems with high dose rates operate in the single pulse mode with limited total dose, and most repetitive pulsed x-ray systems have a low dose rate. This paper develops a compact high-current repetitive pulsed x-ray system with a low-impedance diode to generate high dose rate pulsed x-rays with an average energy below 100 keV. A diode with a double-ring cathode is designed and tested to produce uniform pulsed x-rays. In order to investigate the x-ray intensity and the pulse number of repetitions for different anode thicknesses, five typical thicknesses are tested. The experimental results show that this system can operate stably at a repetitive rate of 0.2 Hz with a peak voltage of about 200 kV and a peak current of about 100 kA. The dose rate is about 2.4 × 105 Gy(LiF)/s, and the average x-ray energy is about 55 keV with the 40 µm thick tantalum anode. The x-ray uniformity is better than 2:1 over the measuring plane.

Phase-Transition-Driven Regional Distribution of Rare-Earth Ions for Multiplexed Upconversion Emissions.

Phase transition of the polymorphs is critical for controlled synthesis and property modulation of functional materials. Upconversion emissions from an efficient hexagonal sodium rare-earth (RE) fluoride compound, ß-NaREF4, which is generally obtained from the phase transition of the cubic (α-) phase counterpart, are attractive for photonic applications. However, the investigation of the α → ß phase transition of NaREF4 and its effect on the composition and architecture is still preliminary. Herein, we investigated the phase transition with two kinds of α-NaREF4 particles. Instead of a uniform composition, the ß-NaREF4 microcrystals exhibited regionally distributed RE3+ ions, in which the RE3+ with a smaller ionic radius (smaller RE3+) sandwiched the RE3+ with a larger ionic radius (larger RE3+). We unravel that the α-NaREF4 particles transformed to ß-NaREF4 nuclei with no controversial dissolution, and the α → ß phase transition toward NaREF4 microcrystals included nucleation and growth steps. The component-dependent phase transition is corroborated with RE3+ ions from Ho3+ to Lu3+ and multiple sandwiched microcrystals were obtained, in which up to five kinds of RE components were distributed regionally. Moreover, with rational integration of luminescent RE3+ ions, a single particle with multiplexed upconversion emissions in wavelength and lifetime domains is demonstrated, which provides a unique platform for optical multiplexing applications.

Highly Polarized Upconversion Emissions from Lanthanide-Doped LiYF4 Crystals as Spatial Orientation Indicators.

Polarized emission, an inherent characteristic that correlated with structure and morphology, is very sensitive to orientation. For the upconversion (UC) emission of lanthanides, the mechanism of polarization is rarely discussed, and the highly polarized UC emissions are poorly developed. Herein, with the benefit of the strong anisotropic crystal field, well-resolved emissions from lanthanide-doped LiYF4 crystals were studied, and highly polarized UC emissions from Er3+ and Ho3+ were investigated. With multiple sub-energy level transitions, the UC emissions are classified into two sets, with transition dipoles being either parallel or perpendicular to the c-axis of the LiYF4 crystal. An optical three-dimensional orientation sensor was further investigated, in which the in-plane angle is referenced from the orientation of the transition dipoles. In contrast, the out-of-plane angle can be deduced from the change in the degree of polarization. This research deepens our understanding of the polarized photoluminescence, and it opens up an avenue toward unique UC orientation sensors.

Lanthanide Upconverted Microlasing: Microlasing Spanning Full Visible Spectrum to Near-Infrared under Low Power, CW Pumping.

The miniaturization of lasers holds promise in ultradense data storage and biosensing, but greater pump power is required to reach the lasing thresholds to overcome increased optical losses with reduced resonant cavity sizes. Here, the whispering galley mode (WGM) of Yb3+ /Tm3+ doped upconversion nanoparticles (UCNPs) coupled with microcavities (≈5 µm) is used to achieve ultralow threshold upconverted lasing at 800 nm with excitation fluences as low as 4 W cm-2 . The continuous-wave (CW) upconverted lasing, with a Q factor on the order of 103 , can remain stable for more than 6 h. In addition, ultralow threshold upconverted microlasers spanning the full visible spectrum from Yb3+ /Er3+ , Yb3+ /Ho3+ , and Yb3+ /Tm3+ doped UCNPs are obtained with the same WGM cavity design. These upconverted microlasers working under low power CW 980 nm laser will enable promising applications in biosensing and imaging.