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By comprehensive analysis of macroscopic characteristics of hardness, electrical conductivity and tensile properties and features of microcosmic morphology, the influence mechanism of process parameters of laser selective melting and following aging treatment on the microstructure, supersaturated solid solution and second-phase precipitation behavior of Al-3.4Mg-1.08Sc alloy fabricated by SLM was discussed. By utilizing the change rules of density and hardness,finally the optimum SLM process parameters and aging system were obtained.The results show that the microstructure of the Al-Mg-Sc alloy fabricated in this experiment is composed of ultrafine equiaxed grains and relatively coarser columnar grains around. The optimal fabrication parameter of Al-Mg-Sc alloy fabricated at platform temperature of 35 ℃ is conducted with scanning speed of 1600 mm/s, laser power of 370 W. The optimum aging time is 12 h at 300 ℃, the yield strength of studied alloy can reach 479.0 MPa through peak aging treatment. Under rapid cooling rate of SLM process, supersaturated solid solution is formed in Al-Mg-Sc alloy, and a large number of nanometer Al3(Sc,Zr) particles are precipitated during the fabrication and heat treatment process, which makes the Al-Mg-Sc alloy present excellent potential of mechanical properties. The fine grain strengthening and the second phase strengthening are the main factors for exhibiting properties of Al-Mg-Sc alloy fabricated by SLM.

Background The contribution of geriatric health examination services of national essential public health services to the detection of abnormal health conditions in the elderly and the awareness of examination results of the elderly has been rarely reported in the current studies. Objective To investigate the abnormal detection of several common diseases including abnormal blood pressure, abnormal blood glucose, overweight and obesity, anemia, fatty liver disease, gallstones or cholecystitis in the health examination of the older adults aged 65 years and above. Methods The older adults aged 65 years and above who visited 20 primary care institutions in 5 cities of 3 provinces in eastern, central and western China were selected as study subjects (excluding those with unclear health examination results in this year) from November to December 2019 by using a multi-stage stratified sampling method, and divided into the general older adults (without hypertension or diabetes), older adults with hypertension, older adults with diabetes. A one-on-one questionnaire survey was conducted on all respondents (The questionnaire included the general demographic characteristics of the respondents and the abnormal detection in the health examination of the elderly) . Results Among 3 018 older adults, 2 033 (67.36%) reported abnormalities in the health examination. There were statistically significant differences in the abnormal detection rates of health examination for the older adults with different types of residence, population, and household registration (P

DNA marked-assisted selection of medicinal plants accelerated the breeding and promotion of new cultivars, and guaranteed the healthy development of Chinese medicinal materials industry. The first disease-resistant cultivar of notoginseng, namely "Miaoxiang Kangqi 1", served as the object of study. We evaluated the Kangqi's resistance of seeds, seedlings and root against the pathological bacteria (Fusarum oxysporum) of root rot. Compared to the traditional cultivars, the disease index of notoginseng seeds declined by 52.0% after inoculation for seven days; the death rate of seedlings and disease index of root respectively decreased by 72.1% and 62.4% after inoculation for 25 days. Additionally, the growth inhibition ratio of notoginseng seeds and seedlings declined after inoculation. The seeds, seedlings and roots of "Miaoxiang Kangqi 1" showed significantly resistant to root rot. The evaluation of disease-resistance of Kangqi provided the basis for the popularization of new cultivar and guaranteed the favoring conduct of notoginseng pollution-free cultivation., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Chinese Pharmaceutical Association.)

Continuous cropping obstacles resulted in the yield losses of Panax ginseng, and affected the development of ginseng industry. Soil fungal communities participated in the key ecological process, and their changes of diversity and composition were related to the continuous cropping obstacles. We analyzed the changes of fungal diversity and composition in the rhizosphere of ginseng using the high-throughput sequencing method, stated the effects of ginseng cultivation on the micro-ecology, and provided effective strategies for overcoming continuous cropping obstacles. Compared to those of the forest soils, the fungal diversity of ginseng rhizosphere soils was increased, and the increasing trends were declined with an increasing years of ginseng cultivation; the relative abundance of Sordariomycetes, Alatospora, Eurotiomycetes, Leotiomycetes, Saccharomycetes, Mucorales and Pezizomycetes were increased in the rhizosphere of ginseng. Pearson's correlation index indicated that soil chemical perporties affected the relative abundance of fungal communities. pH was significantly related to the relative abundance of Dothideomycetes and Alatospora; the content of available potassium was markedly associated with the relative abundance of Dothideomycetes, Alatospora and Mucorales; the content of total nitrogen was significant correlation with the relative abundance of Sordariomycetes and Mucorales. These results indicated that fertilization was one of pivotal factors affecting the rhizosphere micro-ecology of ginseng, and optimization of fertilization system was an effective method to overcome continuous cropping obstacles., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Chinese Pharmaceutical Association.)

DNA marker-assisted selection of medicinal plants is based on the DNA polymorphism, selects the DNA sequences related to the phenotypes such as high yields, superior quality, stress-resistance and so on according to the technologies of molecular hybridization, polymerase chain reaction and high-throughput sequencing, and assists the breeding of new cultivars. This study bred the first disease-resistant cultivar of notoginseng "Miaoxiang Kangqi 1" using the technology of DNA marker-assisted selection of medicinal plants and systematic breeding. The disease-resistant cultivar of notoginseng contained 12 special SNPs based on the analysis of Restriction-site Associated DNA Sequencing (RAD-Seq). Among the SNP (record_519688) was related to the root rot-resistant characteristics, which indicated this SNP could serve as genetic markers of disease-resistant cultivars and assist the systematic breeding. Compared to the conventional cultivated cultivars, the incidence rate of root-rot and rust-rot in notoginseng seedlings decreased by 83.6% and 71.8%, respectively. The incidence rate of root-rot respectively declined by 43.6% and 62.9% in notoginseng cultivation for 2 and 3 years compared with those of the conventional cultivated cultivars. Additionally, the potential disease-resistant groups were screened based on the relative SNP, and this model enlarged the target groups and advanced the breeding efficiency. DNA marker-assisted selection of medicinal plants accelerated the breeding and promotion of new cultivars, and guaranteed the healthy development of Chinese medicinal materials industry., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Chinese Pharmaceutical Association.)