Nonlinear vectorial holography with quad-atom metasurfaces.

Vectorial optical holography represents a solution to control the polarization and amplitude distribution of light in the Fourier space. While vectorial optical holography has been experimentally demonstrated in the linear optical regime, its nonlinear counterpart, which can provide extra degrees of freedom of light-field manipulation through the frequency conversion processes, remains unexplored. Here, we experimentally demonstrate the nonlinear vectorial holography through the second harmonic generation process on a quad-atom plasmonic metasurface. The quad-atom metasurface consists of gold meta-atoms with threefold rotational symmetry. Based on the concept of nonlinear geometric phase, we can simultaneously manipulate the phase and amplitude of the left and right circularly polarized second harmonic waves generated from the quad-atom metasurface. By superposing the two orthogonal polarization components, the quad-atom metasurface can produce nonlinear holographic images with vectorial polarization distributions. The proposed metasurface platform may have important applications in vectorial polarization nonlinear optical source, high-capacity optical information storage, and optical encryption.

Biomimetic Synchronization in Biciliated Robots.

Direct mechanical coupling is known to be critical for establishing synchronization among cilia. However, the actual role of the connections is still elusive-partly because controlled experiments in living samples are challenging. Here, we employ an artificial ciliary system to address this issue. Two cilia are formed by chains of self-propelling robots and anchored to a shared base so that they are purely mechanically coupled. The system mimics biological ciliary beating but allows fine control over the beating dynamics. With different schemes of mechanical coupling, artificial cilia exhibit rich motility patterns. Particularly, their synchronous beating display two distinct modes-analogous to those observed in C. reinhardtii, the biciliated model organism for studying synchronization. Close examination suggests that the system evolves towards the most dissipative mode. Using this guideline in both simulations and experiments, we are able to direct the system into a desired state by altering the modes' respective dissipation. Our results have significant implications in understanding the synchronization of cilia.

A Centimeter-Scale Dielectric Metasurface for the Generation of Cold Atoms.

The single-beam magneto-optical trap (MOT) based on the diffractive optical element offers a new route to develop compact cold atom sources. However, the optical efficiency in the previous single-beam MOT systems is usually low and unbalanced, which will affect the quality of the trapped atoms. To solve this issue, we developed a centimeter-scale dielectric metasurface optical chip with dynamic phase distributions, which was used to split a single incident laser beam into five separate ones with well-defined polarization states and uniform energy distributions. The measured diffraction efficiency of the metasurface is up to 47%. A single-beam MOT integrated with the metasurface optical chip was then used to trap the 87Rb atoms with numbers ∼1.4 × 108 and temperatures ∼7.0 µK. The proposed concept in this work may provide a promising solution for developing ultracompact cold atom sources.

Quasicrystal metasurface for optical holography and diffraction.

Quasicrystal metasurfaces, a kind of two-dimensional artificial optical materials with subwavelength meta-atoms arranged in quasi-periodic tiling schemes, have attracted extensive attentions due to their novel optical properties. In a recent work, a dual-functional quasicrystal metasurface, which can be used to simultaneously generate the diffraction pattern and holographic image, is experimentally demonstrated. The proposed method expands the manipulation dimensions for multi-functional quasicrystal metasurfaces and may have important applications in microscopy, optical information processing, optical encryption, etc.

All-optical ultrafast polarization switching with nonlinear plasmonic metasurfaces.

Optical switching has important applications in optical information processing, optical computing, and optical communications. The long-term pursuit of optical switch is to achieve short switching time and large modulation depth. Among various mechanisms, all-optical switching based on Kerr effect represents a promising solution. However, it is usually difficult to compromise both switching time and modulation depth of a Kerr-type optical switch. To circumvent this constraint, symmetry selective polarization switching via second-harmonic generation (SHG) in nonlinear crystals has been attracting scientists' attention. Here, we demonstrate SHG-based all-optical ultrafast polarization switching by using geometric phase controlled nonlinear plasmonic metasurfaces. A switching time of hundreds of femtoseconds and a modulation depth of 97% were experimentally demonstrated. The function of dual-channel all-optical switching was also demonstrated on a metasurface, which consists of spatially variant meta-atoms. The nonlinear metasurface proposed here represents an important platform for developing all-optical ultrafast switches and would benefit the area of optical information processing.

Treatment options of traditional Chinese patent medicines for dyslipidemia in patients with prediabetes: A systematic review and network meta-analysis.

Objective: To compare the clinical efficacy and safety of SIX Traditional Chinese Patent Medicines (TCPM) recommended by guidelines in improving lipids for patients with prediabetes by network meta-analysis. Methods: Randomized controlled trials of 6 TCPM in the treatment of prediabetes were searched systematically in various databases. After extracting effective data, the risk of bias was assessed using Review Manager 5.3 and Cochrane Collaboration Systems Evaluator's Manual. Network meta-analysis was performed using STATA 15.0 based on the frequency statistical model. The effect size and credibility of the evidence for the intervention were summarized based on a minimal contextualized framework. Results: A total of 27 studies involving 2,227 patients were included. Compared with lifestyle modification (LM), Shenqi + LM [SMD -0.49 (95% CI: -0.85, -0.12)] and Jinqi + LM [SMD -0.44 (95% CI: -0.81, -0.06)] showed statistically significant effect in lowering TG, Shenqi + LM [SMD -0.51 (95%CI: -0.86, -0.17)] and Jinqi + LM [SMD -0.44 (95%CI: -0.80, -0.08)] in lowering TC, Jinlida + LM [SMD -0.31 (95%CI: -0.59, -0.04)] in lowering LDL-C, Shenqi + LM [SMD 0.29 (95%CI: 0.06, 0.51)] and Jinqi + LM [SMD 0.16 (95%CI: 0.01, 0.31)] in increasing HDL-C. Conclusion: For patients with prediabetes, Traditional Chinese patent medicine Jinqi and Shenqi combined with lifestyle modification were associated with a significant reduction in TG and TC, while Shenqi + LM was among the most effective. Jinlida + LM was among the least effective. Systematic Review Registration: https://clinicaltrials.gov/, identifier PROSPERO(CRD42021279332).

Drug-Related Problems of Patients in Primary Health Care Institutions: A Systematic Review.

Introduction: Drug-related problems (DRPs) are not only detrimental to patients' physical health and quality of life but also lead to a serious waste of health care resources. The condition of DRPs might be more severe for patients in primary health care institutions. Objective: This systematic review aims to comprehensively review the characteristics of DRPs for patients in primary health care institutions, which might help find effective strategies to identify, prevent, and intervene with DRPs in the future. Methods: We searched three English databases (Embase, The Cochrane Library, and PubMed) and four Chinese databases (CNKI, CBM, VIP, and Wanfang). Two of the researchers independently conducted literature screening, quality evaluation, and data extraction. Qualitative and quantitative methods were combined to analyze the data. Results: From the 3,368 articles screened, 27 met the inclusion criteria and were included in this review. The median (inter-quartile range, IQR) of the incidences of DRPs was 70.04% (59%), and the median (IQR) of the average number of DRPs per patient was 3.4 (2.8). The most common type of DRPs was "treatment safety." The causes of DRPs were mainly in the prescribing section, including "drug selection" and "dose selection", while patients' poor adherence in the use section was also an important cause of DRPs. Risk factors such as the number of medicines, age, and disease condition were positively associated with the occurrence of DRPs. In addition, the medians (IQR) of the rate of accepted interventions, implemented interventions, and solved DRPs were 78.8% (22.3%), 64.15% (16.85%), and 76.99% (26.09%), respectively. Conclusion: This systematic review showed that the condition of DRPs in primary health care institutions was serious. In pharmaceutical practice, the patients with risk factors of DRPs should be monitored more closely. Pharmacists could play important roles in the identification and intervention of DRPs, and more effective intervention strategies need to be established in the future.