[Research progress in preparations of Panax ginseng].

Panax ginseng, known as the "king of herbs", is a highly valued medicinal plant, and its medicinal parts include roots, stems, leaves, flowers, and fruits, among which the roots are the most commonly used. The main active components of this medicinal plant include triterpenoid saponins, polysaccharides, peptides, and volatile oils. The chemical components and active metabolites endow this herb with a variety of pharmacological effects, and thus this herb is used to treat various diseases and play healthcare roles. Currently, a wide range of preparations of P. ginseng have been officially registered and marketed, including tablets, oral liquids, and injections, which demonstrate good clinical efficacy in regulating immunity, adjuvant treatment of tumors, alleviating fatigue, delaying the aging process, improving glucose and lipid metabolism, treating cardiovascular diseases, and relieving inflammation and pain. The production process and quality standards of these drugs are of great significance to ensure their efficacy. According to the theory that Ginseng Radix et Rhizoma can greatly replenish original Qi, tonify the spleen and lung, promote fluid production to quench thirst, tranquilize mind and enrich the intelligence, this paper systematically summarized the clinical application progress of P. ginseng and rela-ted preparations on the market and prospected the further development of preparations from P. ginseng, providing a reference for further exploring the medicinal value and healthcare function of this herb. The above contents, as an important basis for the in-depth development of P. ginseng and related drugs, increase the possibilities for the application of P. ginseng.

Interlayer donor-acceptor pair excitons in MoSe2/WSe2 moiré heterobilayer.

Localized interlayer excitons (LIXs) in two-dimensional moiré superlattices exhibit sharp and dense emission peaks, making them promising as highly tunable single-photon sources. However, the fundamental nature of these LIXs is still elusive. Here, we show the donor-acceptor pair (DAP) mechanism as one of the origins of these excitonic peaks. Numerical simulation results of the DAP model agree with the experimental photoluminescence spectra of LIX in the moiré MoSe2/WSe2 heterobilayer. In particular, we find that the emission energy-lifetime correlation and the nonmonotonic power dependence of the lifetime agree well with the DAP IX model. Our results provide insight into the physical mechanism of LIX formation in moiré heterostructures and pave new directions for engineering interlayer exciton properties in moiré superlattices.

Quantum interference between dark-excitons and zone-edged acoustic phonons in few-layer WS2.

Fano resonance which describes a quantum interference between continuum and discrete states, provides a unique method for studying strongly interacting physics. Here, we report a Fano resonance between dark excitons and zone-edged acoustic phonons in few-layer WS2 by using the resonant Raman technique. The discrete phonons with large momentum at the M-point of the Brillouin zone and the continuum dark exciton states related to the optically forbidden transition at K and Q valleys are coupled by the exciton-phonon interactions. We observe rich Fano resonance behaviors across layers and modes defined by an asymmetry-parameter q: including constructive interference with two mirrored asymmetry Fano peaks (weak coupling, q > 1 and q < - 1), and destructive interference with Fano dip (strong coupling, ∣q∣ < < 1). Our results provide new insight into the exciton-phonon quantum interference in two-dimensional semiconductors, where such interferences play a key role in their transport, optical, and thermodynamic properties.

Terahertz cavity optomechanics using a topological nanophononic superlattice.

Cavity optomechanical systems operating at the quantum ground state provide a novel way for the ultrasensitive measurement of mass and displacement and provide a new toolbox for emerging quantum information technologies. The high-frequency optomechanical devices could reach the quantum ground state at a high temperature because the access to high frequency is favorable for the cavity optomechanical devices to decouple from the thermal environment. However, reaching ultra-high frequency (THz) is extremely difficult due to the structure of cavity optomechanical devices and properties of materials. In this paper, by introducing acoustic topological interface states, we designed a THz mechanical frequency semiconductor pillar microcavity optomechanical device based on a GaAs/AlAs nanophononic superlattice. In the optomechanical system, multi-optical cavity modes are obtained and the frequency separation between adjacent optical modes is equal to the frequency of the mechanical mode (optomechanical frequency matching). By detuning the laser pump to a lower (higher) energy-resolved sideband to make a spontaneously scattering photon doubly resonate with optical cavity modes at an anti-Stokes (Stokes) frequency and pump frequency, we can achieve an anti-Stokes (Stokes) scattering efficiency 2600 (1800) times larger than that of Stokes (anti-Stokes) scattering, which provides potential for laser cooling and low threshold phonon lasing in the optomechanical system.

Laser Cooling of a Lattice Vibration in van der Waals Semiconductor.

Laser cooling atoms and molecules to ultralow temperatures has produced plenty of opportunities in fundamental physics, precision metrology, and quantum science. Although theoretically proposed over 40 years, the laser cooling of certain lattice vibrations (i.e., phonon) remains a challenge owing to the complexity of solid structures. Here, we demonstrate Raman cooling of a longitudinal optical phonon in two-dimensional semiconductor WS2 by red-detuning excitation at the sideband of the exciton (bound electron-hole pair). Strong coupling between the phonon and exciton and appreciable optomechanical coupling rates provide access to cooling high-frequency phonons that are robust against thermal decoherence even at room temperature. Our experiment opens possibilities of laser cooling and control of individual optical phonon and, eventually, possible cooling of matter in van der Waals semiconductor.

Multiphonon Process in Mn-Doped ZnO Nanowires.

The multiphonon process plays an essential role in understanding electron-phonon coupling, which significantly influences the optical and transport properties of solids. Multiphonon processes have been observed in many materials, but how to distinguish them directly by their spectral characteristics remains controversial. Here, we report high-order Raman scattering up to 10 orders and hot luminescence involving 11 orders of phonons in Mn-doped ZnO nanowires by selecting the excitation energy. Our results show that the intensity distribution of high-order Raman scattering obeys an exponential decrease as the order number increases, while hot luminescence is fitted with a Poisson distribution with a resonance factor. Their linewidth and frequency can be well explained by two different transition models. Our work provides a paradigm for understanding the multiphonon-involved decay process of an excited state and may inspire studies of the statistical characteristics of excited state decay.

Magneto-Raman Study of Magnon-Phonon Coupling in Two-Dimensional Ising Antiferromagnetic FePS3.

Recently, the coupling between magnons (quanta of spin waves) and phonons (quanta of lattice vibrations) in two-dimensional (2D) antiferromagnet FePS3 offers a myriad of applications ranging from spintronic devices to quantum information technologies. However, the reported magnon-phonon coupling in the FePS3 flake using Raman measurements requires an ultrahigh magnetic field up to 30 T. Here, we investigate the magnon-phonon coupling in FePS3 by near-resonant magneto-Raman spectroscopy under a relatively small magnetic field (|H0| ≤ 9 T). Under near-resonant excitation, we find more pronounced coupling effects that are absent in non-resonant excitation: three optical phonons sensitive to the applied magnetic field are resolved, two of which show a frequency anti-crossing coupling with magnon, while the other coupled phonon exhibits only a polarization-coupled character without frequency anti-crossing. Besides, our polarized Raman results also show the polarization transferring between coupled magnon-phonon modes. On the basis of a modified theoretical model, we can well explain the measured Raman spectra.

Donor-Acceptor Pair Quantum Emitters in Hexagonal Boron Nitride.

Quantum emitters are needed for a myriad of applications ranging from quantum sensing to quantum computing. Hexagonal boron nitride (hBN) quantum emitters are one of the most promising solid-state platforms to date due to their high brightness and stability and the possibility of a spin-photon interface. However, the understanding of the physical origins of the single-photon emitters (SPEs) is still limited. Here we report dense SPEs in hBN across the entire visible spectrum and present evidence that most of these SPEs can be well explained by donor-acceptor pairs (DAPs). On the basis of the DAP transition generation mechanism, we calculated their wavelength fingerprint, matching well with the experimentally observed photoluminescence spectrum. Our work serves as a step forward for the physical understanding of SPEs in hBN and their applications in quantum technologies.

Awareness, perception and experience on child restraint system (CRS) and its legislation among Malaysian parents with newborns.

Objective: The aim of this study was to explore parents' awareness and usage of CRS, incentives and challenges in CRS use, as well as their perception about potential CRS legislation in Malaysia.Methods: This was a cross-sectional study conducted in a public tertiary care center in Northern Malaysia. A self-developed researcher-assisted questionnaire was developed in English and translated into Malay language, to explore parents' awareness ad CRS usage, as well as the incentives and barriers in CRS use. Parents of a newborn were conveniently sampled, excluding parents with pre-term newborn or those without a car. Upon obtaining written informed consent, the parents were allowed to answer the questionnaire within 20 minutes, assisted by the researchers. Parents who were found not using CRS for their newborn were given a digital pamphlet with CRS-related information via mobile devices.Results: A total of 200 parents were approached and 193 of them consented to participate in this study. The majority of the parents (87.6%) were aware of CRS, but only half of them (57.0%) provided a CRS for their current newborn. From 100 CRS users, most of them used a CRS for "child's safety" purposes (84.5%). Among 83 CRS nonuser, nearly half of them (45.8%) perceived that it is adequate to carry their child during traveling without using a CRS. When exploring previous experience in using CRS among all parents (n = 193), more than half of them (63.9%) faced difficulty as their child refused to use the CRS. More than half (54.9%) of all parents were not aware about the possible CRS legislation in Malaysia. However, the majority of them (90.7%) agreed with the implementation of CRS law.Conclusions: Although majority of the parents were aware about CRS, but only half had a CRS for their current newborn. Most of the parents supported CRS legislation in Malaysia, but assistance will be required to help them through challenges related to CRS use.