A Triboelectric-Electromagnetic Hybrid Nanogenerator with Magnetic Coupling Assisted Waterproof Encapsulation for Long-Lasting Energy Harvesting.

Ocean energy harvesting based on a triboelectric nanogenerator (TENG) has great application potential, while the encapsulation of triboelectric devices in water poses a critical issue. Herein, a triboelectric-electromagnetic hybrid nanogenerator (TE-HNG) consisting of TENGs and electromagnetic generators (EMGs) is proposed to harvest water flow energy. A magnetic coupling transmission component is applied to replace traditional bearing structures, which can realize the fully enclosed packaging of the TENG devices and achieve long-lasting energy harvesting from water flow. Under the intense water impact, magnetic coupling reduces the possibility of internal gear damage due to excessive torque, indicating superior stability and robustness compared to conventional TENG. At the waterwheel rotates speed of 75 rpm, the TE-HNG can generate an output peak power of 114.83 mW, corresponding to a peak power density of 37.105 W m-3. After 5 h of continuous operation, the electrical output attenuation of TENG is less than 3%, demonstrating excellent device durability. Moreover, a self-powered temperature sensing system and a self-powered cathodic protection system based on the TE-HNG are developed and illustrated. This work provides a prospective strategy for improving the output stability of TENGs, which benefits the practical applications of the TENGs in large-scale blue energy harvesting.

Boron-based ternary MgTa2B6 cluster: a turning nanoclock with dynamic structural fluxionality.

Boron-based complex clusters are a fertile ground for the exploration of exotic chemical bonding and dynamic structural fluxionality. Here we report on the computational design of a ternary MgTa2B6 cluster via global structural searches and quantum chemical calculations. The cluster turns out to be a new member of the molecular rotor family, closely mimicking a turning clock at the subnanoscale. It is composed of a hexagonal B6 ring with a capping Ta atom at the top and bottom, whereas the Mg atom is linked to one Ta site as a radial Ta-Mg dimer. These components serve as the dial, axis, and hand of a nanoclock, respectively. Chemical bonding analyses reveal that the inverse sandwich Ta2B6 motif in the cluster features 6π/6σ double aromaticity, whose electron counting conforms to the (4n + 2) Hückel rule. The Ta-Mg dimer has a Lewis-type σ bond, and the Mg site has negligible bonding with B6 ring. The ternary cluster can be formulated as an [Mg]0[Ta2B6]0 complex. Molecular dynamics simulations suggest that the cluster is structurally fluxional analogous to a nanoclock, even at a low temperature of 100 K. The Ta-Mg hand turns almost freely around the Ta2 axis and along the B6 dial. The tiny intramolecular rotation barrier is less than 0.3 kcal mol-1, being dictated by the bonding nature of double 6π/6σ aromaticity. The present system offers a new type of molecular rotor in physical chemistry.

Be3B11- cluster: a dynamically fluxional beryllo-borospherene.

The beryllium-doped Be3B11- cluster has two nearly isoenergetic isomers, adopting the smallest trihedral spherical geometries with a boron single-chain skeleton. The B11 skeleton in the global minimum (C2v, 1A1) comprises three conjoined boron rings (one B8/two B7) on the waist, sharing two B3 equilateral triangles at the top and bottom, respectively. However, the local minimum (Cs, 1A') has one deformed B4 pyramid at the top. The drastic structural transformation of B11 skeletons from perfectly planar B11 clusters mainly profited from robust electrostatic interaction between Be atoms and B11 skeletons. The dynamic simulations suggest that two species can interconvert via a novel mechanism, that is "triangle-pyramid-triangle", which facilitates the free migration of boron atoms in the B11 skeleton, thereby showing the fascinating dynamic fluxionality. The chemical bonding analyses reveal that the B11 skeleton is covered by two types of delocalized π bonds in an orthogonal direction, which leads to its spherical aromaticity.

Boron-based Pd3B26 alloy cluster as a nanoscale antifriction bearing system: tubular core-shell structure, double π/σ aromaticity, and dynamic structural fluxionality.

Boron-based nanoclusters show unique geometric structures, nonclassical chemical bonding, and dynamic structural fluxionality. We report here on the theoretical prediction of a binary Pd3B26 cluster, which is composed of a triangular Pd3 core and a tubular double-ring B26 unit in a coaxial fashion, as identified through global structural searches and electronic structure calculations. Molecular dynamics simulations indicate that in the core-shell alloy cluster, the B26 double-ring unit can rotate freely around its Pd3 core at room temperature and beyond. The intramolecular rotation is virtually barrier free, thus giving rise to an antifriction bearing system (or ball bearing) at the nanoscale. The dimension of the dynamic system is only 0.66 nm. Chemical bonding analysis reveals that Pd3B26 cluster possesses double 14π/14σ aromaticity, following the (4n + 2) Hückel rule. Among 54 pairs of valence electrons in the cluster, the overwhelming majority are spatially isolated from each other and situated on either the B26 tube or the Pd3 core. Only one pair of electrons are primarily responsible for chemical bonding between the tube and the core, which greatly weaken the bonding within the Pd3 core and offers structural flexibility. This is a key mechanism that effectively diminishes the intramolecular rotation barrier and facilitates dynamic structural fluxionality of the system. The current work enriches the field of nanorotors and nanomachines.

NAl4X4 + (X = S, Se, Te): Clusters with a planar tetracoordinate nitrogen and significantly improved stability.

The design of clusters featuring non-classical planar hypercoordinate atoms (phAs) often depends on the delocalized multicenter bonds involving reactive electron-deficient elements, which both destabilize the clusters and lead to difficulty in achieving the phA arrangement for electronegative elements such as nitrogen due to their preference for localized bonds. In this work, we computationally designed a series of aluminum chalcogenide clusters NAl4X4 + (X = S, Se, Te) with a desired planar tetracoordinate nitrogen and meaningfully improved chemical stability, as evidenced by the wide gaps (6.51-7.23 eV) between their highest occupied molecular orbitals and lowest unoccupied molecular orbitals, high molecular rigidity (dynamically stable up to 1500 K), and exclusively low global energy minima nature (their isomers locate at least 51.2 kcal/mol higher). Remarkably, these clusters are stabilized by peripheral chalcogen atoms, which not only sterically protect the NAl4 core moiety but also electronically compensate for the electron-deficient aluminum atoms via X → Al π back bonds, meeting the description of our recently proposed "electron-compensation" strategy.

Boron-Based Inverse Sandwich V2B7- Cluster: Double π/σ Aromaticity, Metal-Metal Bonding, and Chemical Analogy to Planar Hypercoordinate Molecular Wheels.

Inverse sandwich clusters composed of a monocyclic boron ring and two capping transition metal atoms are interesting alloy cluster systems, yet their chemical bonding nature has not been sufficiently elucidated to date. We report herein on the theoretical prediction of a new example of boron-based inverse sandwich alloy clusters, V2B7-, through computational global-minimum structure searches and quantum chemical calculations. This alloy cluster has a heptatomic boron ring as well as a perpendicular V2 dimer unit that penetrates through the ring. Chemical bonding analysis suggests that the inverse sandwich cluster is governed by globally delocalized 6π and 6σ frameworks, that is, double 6π/6σ aromaticity following the (4n + 2) Hückel rule. The skeleton B-B σ bonding in the cluster is shown not to be strictly Lewis-type two-center two-electron (2c-2e) σ bonds. Rather, these are quasi-Lewis-type, roof-like 4c-2e V-B2-V σ bonds, which amount to seven in total and cover the whole surface of inverse sandwich in a truly three-dimensional manner. Theoretical evidence is revealed for a 2c-2e Lewis σ single bond within the V2 dimer. Direct metal-metal bonding is scarce in inverse sandwich alloy clusters. The present inverse sandwich alloy cluster also offers a new type of electronic transmutation in physical chemistry, which helps establish an intriguing chemical analogy between inverse sandwich clusters and planar hypercoordinate molecular wheels.

Chemical Bonding and Dynamic Structural Fluxionality of a Boron-Based Na5B7 Sandwich Cluster.

Doping alkali metals into boron clusters can effectively compensate for the intrinsic electron deficiency of boron and lead to interesting boron-based binary clusters, owing to the small electronegativity of the former elements. We report on the computational design of a three-layered sandwich cluster, Na5B7, on the basis of global-minimum (GM) searches and electronic structure calculations. It is shown that the Na5B7 cluster can be described as a charge-transfer complex: [Na4]2+[B7]3-[Na]+. In this sandwich cluster, the [B7]3- core assumes a molecular wheel in shape and features in-plane hexagonal coordination. The magic 6π/6σ double aromaticity underlies the stability of the [B7]3- molecular wheel, following the (4n + 2) Hückel rule. The tetrahedral Na4 ligand in the sandwich has a [Na4]2+ charge-state, which is the simplest example of three-dimensional aromaticity, spherical aromaticity, or superatom. Its 2σ electron counting renders σ aromaticity for the ligand. Overall, the sandwich cluster has three-fold 6π/6σ/2σ aromaticity. Molecular dynamics simulation shows that the sandwich cluster is dynamically fluxional even at room temperature, with a negligible energy barrier for intramolecular twisting between the B7 wheel and the Na4 ligand. The Na5B7 cluster offers a new example for dynamic structural fluxionality in molecular systems.

Structures and chemical bonding of boron-based B12O and B11Au clusters. A counterexample in boronyl chemistry.

Boron oxide clusters have structural diversity and unique chemical bonding, and recent literature has shown that boronyl complexes dominate boron-rich oxide clusters. A counterexample in boronyl chemistry is presented in this work. Using global structural searches, electronic structure calculations, and chemical bonding analyses, we shall report on the computational design of two boron-based quasi-planar or planar clusters: B12O and B11Au. Contrary to expectation, the B12O cluster has a circular quasi-planar shape with a peripheral B-O-B bridge, which resembles bare B12 cluster. It does not contain a boronyl ligand. The isomeric boronyl complex turns out to be 10.32 kcal mol-1 higher in energy at the single-point CCSD(T) level. In contrast, B11Au cluster behaves normally with an elongated B11 moiety and a terminal Au ligand. Chemical bonding analyses reveal three-fold π/σ aromaticity in circular B12O cluster, including global 6π aromaticity, as well as spatially isolated inner 2σ aromaticity and outer 10σ aromaticity. The three-fold 6π/2σ/10σ aromaticity underlies the stability of B12O cluster. This bonding picture is unknown for bare B12 cluster and its derivatives. The elongated B11Au cluster has conflicting π/σ aromaticity (with 6π versus 8σ electron-counting). The B12O cluster is actually isoelectronic with bare B12 cluster in terms of delocalized π/σ bonding, which inherits the structural and electronic robustness of the latter.

Ternary 14-electron XB2Be2 (X = Si, Ge, Sn, Pb) clusters: a planar tetracoordinate silicon (ptSi) system and its ptGe/Sn/Pb congeners.

A class of ternary 14-electron clusters, XB2Be2 (X = Si, Ge, Sn, Pb), have been computationally predicted with a planar tetracoordinate silicon (ptSi) unit, as well as its heavier ptGe/Sn/Pb congeners. These pentaatomic ptSi/Ge/Sn/Pb species are established as global-minimum structures via computer global searches, followed by electronic structure calculations at the PBE0-D3, B3LYP-D3, and single-point CCSD(T) levels. Molecular dynamics simulations indicate that they are also kinetically stable against isomerization or decomposition. Chemical bonding analyses show that the clusters have double 2π/2σ aromaticity. The latter concept underlies the stability of ptSi/Ge/Sn/Pb clusters, overriding the 14-electron count or its variants, such as the 18-electron rule. No sp3 hybridization occurs in these species, which naturally explains why they are ptSi/Ge/Sn/Pb (rather than traditional tetrahedral) systems.

Y©B8C4 cluster: a boron-carbon molecular wheel with dodeca-coordination number in plane.

Computational evidence is reported for the largest planar molecular wheel of the Y©B8C4 cluster, featuring an yttrium atom enclosed by a highly symmetric B8C4 ring. The B8C4 ring is viable in the -(BCB)4- form with double 9π/10σ aromaticity. The centered yttrium atom is dodeca-coordinated with the peripheral B8C4 ring, which sets a record coordination number for a planar structure in chemistry heretofore.

Clinical assessments and gait analysis for patients with Trimalleolar fractures in the early postoperative period.

BACKGROUND: Trimalleolar fracture is a common ankle fracture with serious complications and costly healthcare problem. Most studies used clinical assessments to evaluate the functional status of the patients. Although clinical assessments are valid, they are static and subjective. Dynamic, objective and precise evaluations such as gait analysis are needed. Ankle biomechanics studies on gait in patients with trimalleolar fractures are still rare. This study aimed to investigate the clinical outcomes and gait biomechanics in patients with trimalleolar fractures in the early postoperative period and compared to healthy controls. METHODS: This was a cross-sectional study. 12 patients with trimalleolar fractures were recruited, and 12 healthy people served as controls. All patients underwent clinical assessments: Olerud and Molander ankle score (OMAS), ankle swelling and passive range of motion (ROM) of ankle, and completed gait biomechanical analysis when weight-bearing was allowed: temporal-spatial parameters, plantar pressure distributions, and surface electromyography (sEMG). The control group only performed gait test. RESULTS: Patients had poor outcomes of clinical assessments in the short-term. During gait analysis, patients presented compromised gait patterns: shorter step length, larger step width, slower walking speed and shorter single support compared to healthy controls (P < 0.001), and patients showed asymmetrical gait. Symmetry index of step width and walking speed were mainly correlated with the difference of ankle inversion ROM between two sides (R = -0.750, P = 0.005; R = -0.700, P = 0.011). During walking, patients showed abnormal dynamic plantar pressure features (mainly in the hindfoot and forefoot regions), and the IEMG (integrated electromyography) of tibial anterior muscle (TA) and peroneal longus muscle (PL) were larger than healthy controls (P = 0.002, 0.050). CONCLUSIONS: Patients with trimalleolar fractures showed physical impairments of the ankle, and presented altered gait parameters compared to healthy subjects in the short-term. The ankle stability of patients declined, and deficits in TA and PL muscle ability might contribute to it. Restoring complete muscle functions and improving passive ankle ROM are significant to promote the recovery of a normal gait pattern.

Real-time capture of single particles in controlled flow by a rapidly generated foci array with adjustable intensity and pattern.

We propose a new, to the best of our knowledge, technique to capture single particles in real-time in a microfluidic system with controlled flow using micro-pillar traps fabricated by one-step. The micro pillars are fabricated in parallel by femtosecond multi-foci laser beams, which are generated by multiplexing gratings. As the generation process does not need integration loops, the pattern and the intensity distribution of the foci array can be controlled in real-time by changing the parameters of gratings. The real-time control of the foci array enables rapidly fabricating microtraps in the microchannel with adjustment of the pillar spaces and patterns according to the sizes and shapes of target particles. This technology provides an important step towards using platforms based on single-particle analysis, and it paves the way for the development of innovative microfluidic devices for single-cell analysis.

Concentric Inner 2π/6σ and Outer 10π/14σ Aromaticity Underlies the Dynamic Structural Fluxionality of Planar B19- Wankel Motor Cluster.

Planar C2v B19- global-minimum (GM) cluster is known as a molecular Wankel motor, featuring unique chemical bonding and structural fluxionality. While the geometry, bonding, and molecular dynamics of the cluster are documented in the literature, it remains warranted to fully understand its bonding nature and unravel the mechanism behind the structural dynamics. We shall offer herein an updated bonding model on the bases of canonical molecular orbital (CMO) analysis and adaptive natural density partitioning (AdNDP), further aided by natural bond orbital (NBO) analysis and orbital composition calculations. The computational data indicate that the B19- cluster has inner 2π/6σ and outer 10π/14σ concentric 4-fold π/σ aromaticity. Being spatially isolated from each other, the inner B6 disk supports 2π and 6σ subsystems, whereas the outer B18 double-ring ribbon has 10π and 14σ subsystems. All 4-fold π/σ subsystems are intrinsically delocalized and conform to the (4n + 2) Hückel rule for aromaticity. The change of Wiberg bond index (WBI) from GM to transition-state (TS) for radial B-B links is minimal and uniform, which offers a semiquantitative measure of structural dynamics and underlies the low energy barrier.

Rapid fabrication of high-resolution multi-scale microfluidic devices based on the scanning of patterned femtosecond laser.

Femtosecond-laser-induced two-photon polymerization has distinct advantages in micro-nanofabrication due to its intrinsic three-dimensional processing capability and high precision with sub-100 nanometer fabrication resolution. However, the high resolution causes a drawback in fabricating large-scale structures due to unacceptably long processing times. To solve this problem, we applied the patterned focus as the basic element for scanning processing. Theoretically, the relationship between patterned-focus scanning parameters and the uniformity of scanned light field was analyzed and optimized. Experimentally, we quantitatively investigated the relationship between the microstructure surface quality and the parameters of patterned-focus scanning. Based on above, we put forward a hybrid method that combines the femtosecond laser patterned exposure with direct-writing fabrication to rapidly fabricate large-scale microfluidic devices for various practical applications.

Are all planar and quasi-planar boron clusters aromatic? Counter examples of island or global π antiaromaticity from chemical bonding analysis.

Boron is an electron-deficient element. The flatland of planar or quasi-planar (2D) boron clusters is believed to possess aromaticity for all members, which remains a fundamental issue in debate in boron chemistry. Using a selected set of D2h B62-, C2h B282-, and C2v B29- clusters as counter examples, we shall present computational evidence for global or island π antiaromaticity in 2D boron clusters. The latter two are flattened for the purpose of clarity, which model their quasi-planar C2 or Cs monoanion clusters observed in prior gas-phase experiments. Chemical bonding in the clusters is elucidated collectively on the basis of canonical molecular orbital (CMO) analysis, adaptive natural density partitioning (AdNDP), electron localization functions (ELFs), and localized molecular orbital (LMO) analysis. These results are complementary to each other and yet highly coherent. As a quantitative indicator, nucleus-independent chemical shifts (NICSs) are calculated at selected specific points in the clusters, which help differentiate between π aromaticity and antiaromaticity. Intriguingly, triangular sites in the same boron cluster can be aromatic, antiaromatic, or nonaromatic, despite the fact that they are physically indistinguishable. The phenomenon is understood in analogy to hydrocarbons and polycyclic aromatic hydrocarbons (PAHs). Even perfect sheet-like boron clusters are convertible to the PAH analogous systems. This work provides compelling examples for global and island π antiaromaticity in the 2D boron clusters.

Anchoring a bow-shaped boron single chain in binary Be6B7- cluster: hybrid octagonal ring, multifold π/σ aromaticity, and dual electronic transmutation.

Elemental boron clusters do not form linear chain or monocyclic ring structures, which is in contrast to carbon. Based on computer global searches and quantum chemical calculations, we report on the viability of a curved boron single chain in binary Be6B7- cluster. The boron motif assumes a bow shape, being anchored on a Be6 prism. Such a motif, which appears to be highly strained in its free-standing form, is exotic in boron-based clusters and nanostructures. Chemically, the cluster is analogous to a "clam-and-pearl-chain" system at the nanoscale (about 1 nm in size), in which a Be6 clam moderately opens its mouth, except that a B7 pearl chain is too large to be encapsulated inside. The picture differs from a three-layered sandwich. This cluster features a hybrid Be2B7 monocyclic ring, which is octagonal in nature and supports double 10π/6σ aromaticity. The number of π bonds substantially surpasses that in bare boron clusters of similar sizes. Two Be3 rings in the prism are also σ aromatic, albeit with effective 1σ/1σ electron-counting only. The unique multifold 1σ/10π/6σ/1σ aromaticity governs the geometry of the Be6B7- cluster, which can also be rationalized using the concept of dual electronic transmutation.

Boron-based ternary Rb6Be2B6 cluster featuring unique sandwich geometry and a naked hexagonal boron ring.

Computational evidence is reported on a boron-based ternary Rb6Be2B6 cluster as the "Big Mac" sandwich on a subnanoscale with thickness of 0.58 nm. The core hexagonal B6 ring, occurring in the naked form due to double 6π/6σ aromaticity, is capped by two tetrahedral BeRb3 ligands. Such a B6 motif is scarce in boron clusters. The sandwich cluster has four-fold 2σ/6π/6σ/2σ aromaticity and its tetrahedral BeRb3 ligand is the simplest case of three-dimensional aromaticity (or spherical aromaticity). The sandwich can be formulated as a charge-transfer complex, [Rb3Be]3+[B6]6-[BeRb3]3+, whose components are held together by robust electrostatics, facilitating dual-mode dynamic fluxionality.

Acceptance of the 'Assessment of Physiotherapy Practice (Chinese)' as a standardised evaluation of professional competency in Chinese physiotherapy students: an observational study.

BACKGROUND: Development of an entry-level physiotherapy curriculum in China currently follows the World Confederation for Physical Therapy (WCPT) guidelines, however there is no standard, validated, assessment tool for physiotherapy practice in use in China. This article reports the process of translation of the "Assessment of Physiotherapy Practice" (APP), a validated assessment instrument adopted by all universities in Australia and New Zealand, into Chinese (APP-Chinese) and its implementation by Chinese physiotherapy clinical educators (CEs) and students during clinical placements. METHODS: The process of forward and backward translation of the APP was undertaken by a team of academics from universities in Shanghai, Hong Kong, United States and Australia. An APP-Chinese version was produced and used for assessment of the clinical performance of 4th year students at a university in Shanghai. Feedback on the implementation of the APP-Chinese was solicited from students and CEs using the same two questionnaires employed to assess implementation of the original APP. RESULTS: All CEs agreed that the rules used to score the APP-Chinese were helpful in assessing student performance. Over 90% of the CEs considered the APP-Chinese was pragmatic for use in the clinical environment in China. All students agreed with the rating of their performance on the APP-Chinese marked by their educators, and that the performance indicators were useful in guiding their expected performance behaviour. CONCLUSION: The APP-Chinese is the first standardised assessment tool for evaluation of clinical performance of physiotherapy students in China and was shown to be well accepted by both students and CEs in the clinical education unit and university involved in this study.

[Rationality of Asari Radix et Rhizoma in Qingfei Paidu Decoction based on literature analysis].

Qingfei Paidu Decoction is a traditional Chinese medicine compound recommended by National Health Commission of the People's Republic of China and National Administration of Traditional Chinese Medicine for clinical therapies of coronavirus disease 2019(COVID-19). Qingfei Paidu Decoction consists of 21 traditional Chinese medicines, such as Asari Radix et Rhizoma. However, the dosage of Asari Radix et Rhizoma has been questioned by some people, because of one ancient proverb. To explore the rationality of the dosage of Asari Radix et Rhizoma in Qingfei Paidu Decoction, this study systematically examined the ancient and modern physicians' understanding of the toxicity of Asari Radix et Rhizoma, and collated the application and dosage of Asari Radix et Rhizoma in ancient prescriptions and modern clinics based on literature analysis. As a result, we found that ancient and modern physicians have different understanding on the toxicity of Asari Radix et Rhizoma and that the theory about the dosage of Asari Radix et Rhizoma is flawed. We also found that the dose of Asari Radix et Rhizoma in ancient and modern clinical applications was not constrained by ancient experience. Physicians usually increase the dosage of Asari Radix et Rhizoma in clinical therapy according to the actual conditions, and there were no adverse reactions. Additionally, according to laws and regulations concerning medical affairs, physician could increase or decrease the dosage of the drug under special circumstances. Based on the analysis of safety and effectiveness of Asari Radix et Rhizoma in Qingfei Paidu Decoction, we conclude that the dose of Asari Radix et Rhizoma in Qingfei Paidu Decoction is safe, effective and reasonable.

[Analysis of property and efficacy of traditional Chinese medicine in staging revention and treatment of coronavirus disease 2019].

Coronavirus disease 2019(COVID-19) triggered a severe and complicated epidemic situation, and it is of great significance to discuss the rules and characteristics of the prescription of COVID-19 in traditional Chinese medicine. This study collected prevention and treatment approaches of traditional Chinese medicine for COVID-19 released from the National Health Committee of China, 7 provinces and municipal health committees, the Chinese Medicine Administration and Handbook of Traditional Chinese Medicine Diagnosis and Treatment of COVID-19 between January 1 and February 18, 2020, and prescriptions prepared by 3 masters of Chinese medicine and 4 well-known Chinese medicine experts. These information were selected according to the inclusion and exclusion criteria, and EpiData 3.0 software was used to establish the "Traditional Chinese Medicine Prescription Library for the Prevention and Treatment of COVID-19" and the "Common Database of Traditional Chinese Medicine for the Prevention and Treatment of COVID-19". A total of 93 effective Chinese medicine prescriptions and a total of 157 kinds of constituent medicines were collected. Data analysis was performed by SPSS 18.0 software. The results showed that: ①most of the medicines are with cold and warm properties, 69 with cold medicines, accounting for 43.95%, 57 with warm medicines, accounting for 36.31%, and less with hot medicines, taking up 1.27%; ②there are many pungent, bitter and sweet medicines, and the distribution of medicinal flavors is different at different disease stage. The pungent medicines are mostly found in the early stage, the bitter drugs are the main flavor in the middle and severe stage, and the sweet medicines are mostly used in the recovery stage; ③the meridian of the drug is more concentrated at the lung, stomach, and heart, and most of drugs are into the lung meridian, accounting for 24.55%; these medicines are mostly into the lungs and stomach in the initial and middle stages, and into the heart and kidney in severe stages; ④oral drugs are mostly non-toxic, among which only 6 kinds are toxic, namely Armeniacae Semen Amarum, Dryopteridis Crassirhizomatis Rhizoma, Paridis Rhizoma, Pinelliae Rhizoma, Aconiti Lateralis Radix Praeparaia; ⑤most of the drugs have five types of functions: treating exterior syndromes, resolving dampness, clearing heat, replenishing deficiency, resolving phlegm, cough, and asthma. In the early stage, both drugs for treating exterior syndromes and heat clearing drugs were equally used, accounting for 18.81% each. In the middle stage, drugs resolving phlegm, cough, and asthma drugs are more often used, accounting for 29.61%. In the severe stage, heat clearing drugs are mostly used, accounting for 33.33%. During the recovery period, tonic deficiency drugs are used the most, accounting for 36.47%. The medical characteristics and efficacy of Chinese medicine in preventing and treating COVID-19 are closely related to the understanding of the etiology of Chinese medicine and the location and pathogenesis of the disease. Staged medication and local conditions need attention during the identification and treatment of COVID-19 clinical syndromes.