Analysis on the medication and methods of ancient traditional Chinese medicine in the prevention of plague

Background:To analyze the medication and methods of ancient traditional Chinese medicine for the prevention of plague and seasonal pathogen in order to reduce the spread of infectious diseases such as flu and protect the susceptible people.Methods:Search the medication and the methods for preventing plague and seasonal pathogen in the Chinese Medical Code,classify and summarize the methods,perform frequency analysis and efficacy cluster analysis on Chinese medicines of involved medicines.Results:The methods of preventing ancient plague were as follows:burning and fumigating Chinese medicines,medicating nostrils,wearing bags filled with Chinese medicines,oral Chinese medicines and applying medicines to skin.The 3 main ways for drugs to work were external medication,nostril inhalation,and internal absorption.The Chinese medicines for preventing plague are mostly warm in nature and pungent in flavour,belonging to the spleen,stomach,liver,lung meridian.The 3 categories of drugs obtained by cluster analysis are C1:drugs for facilitating lung,relieving exterior and dissipating cold,such as Cangzhu(Atractylodis rhizoma)-Qianghuo(Notopterygh rhizoma et radix)-Xixin(Asari radix et rhizoma)-Baizhi(Angelicae dahuricae radix)-Fangfeng(Saposhnikoviae radix)-Zaojiao(Gleditsiae sinensis fructus);C2:drugs for promoting blood circulation and removing blood stasis,such as Xionghuang(Realgar)-Zhusha(Cinnabaris)-Dahuang(Rhei radix rhizoma)-Chuanxiong(Chuanxiong rhizoma)-Jiegeng(Platycodonis radix);C3:drugs for replenishing Qi(it is the most basic element that constitutes human body and maintains life activities in traditional Chinese medicine)and tonifying the spleen,such as Gancao(Glycyrrhizae radix et rhizoma)-Dazao(Jujubae fructus)-Ganjiang(Zingiberis rhizoma)-Rougui(Cinnamomi cortex)-Gansong(Nardostachyos radix et rhizoma)-Chenpi(Citri reticulatae pericarpium)-Baizhu(Atractylodis macrocephalae rhizoma).Conclusion:Through analysis the medication and methods of ancient traditional Chinese medicine for the prevention of plague,we can provide reference for modern research from the original plague prevention methods,and make an important contribution to the use of traditional Chinese medicine in the prevention and treatment of epidemic infectious diseases in modern clinic.

Microstructures and properties of Cu-Cr-W composite coatings fabricated by surface mechanical alloying technique

Cu-Cr-W composite coatings were prepared by mechanical alloying(MA)method using different powder ratios,rotational speeds and milling time.The micro structures and chemical compositions of as-synthesized coatings were analyzed by scanning electron microscopy(SEM)and energy-dispersive spectroscopy(EDS).Phases of ball-milled powders were identified by X-ray diffraction(XRD).The results indicate that the coating fabricated with powder ratio of 40 wt%Cu-Cr-W has better surface and cross-sectional microstructures and higher microhardness.The comparisons of cross-sectional micro structures of the coatings fabricated at different rotational speeds suggest that rotational speed of 300 r·min-1is the optimal for fabrication the coating,and the optimal milling time for the formation of coating is 7 h.The results of microhardness test show that the hardness of the substrate is largely improved because of the as-fabricated coatings.The results of the friction and wear tests indicate that the wear resistance of the copper substrate is improved after the deposition of Cu-Cr-W coating on it.The coating fabricated for 7 h exhibits the lowest friction coefficient,indicating its favorable friction and wear resistance.The formation mechanism of the coating was elucidated.According to the investigations in this work,the Cu-Cr-W coating fabricated by MA method is considered to be effective to reinforce the copper substrate.

Microstructure and mechanical properties of Ti-Cu amorphous coating synthesized on pure Cu substrate by mechanical alloying method

Mechanical alloying method was applied to fabricate coating with amorphous structure on pure Cu substrate.The microstructure,the phase composition and the mechanical properties including microhardness and wear resistance of the coating were,respectively,characterized and analyzed.The results show that the coating is rough but continuous.It has favorable adhesion to the substrate.The coating is made up of an inner composite layer and an outer amorphous layer.The microhardness and the wear resistance of the pure Cu substrate are improved because of the bilayer structure.The formation mechanism of the coating was discussed.The as-synthesized coating is considered to be effective to strengthen the surface of pure Cu substrate.

Dynamical Behavior of SEIR-SVS Epidemic Models with Nonlinear Incidence and Vaccination

For some infectious diseases such as mumps,HBV,there is evidence showing that vaccinated individuals always lose their immunity at different rates depending on the inoculation time.In this paper,we propose an age-structured epidemic model using a step function to describe the rate at which vaccinated individuals lose immunity and reduce the age-structured epidemic model to the delay differential model.For the age-structured model,we consider the positivity,boundedness,and compactness of the semiflow and study global stability of equilibria by constructing appropriate Lyapunov functionals.Moreover,for the reduced delay differential equation model,we study the existence of the endemic equilibrium and prove the global stability of equilibria.Finally,some numerical simulations are provided to support our theoretical results and a brief discussion is given.