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Pot experiments were conducted using Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) and Phoebe bournei (Hemsl.) Yang) to investigate whether soil microplastics adversely affect the nurturing and renewal of plantations. Microplastics composed of polyethylene and polypropylene with a size of 48 µm were used. The treatments included a control group (without microplastics) and groups treated with microplastic concentrations of 1% and 2% (w/w). The effects of microplastics on the growth, photosynthetic pigments in leaves, antioxidant systems, and osmotic regulation substances of the seedlings were analysed by measuring the seedling height, ground-line diameter growth, chlorophyll (chlorophyll a, chlorophyll b, and total chlorophyll) contents, antioxidant enzyme (superoxide dismutase, peroxidase, catalase) activities, and malondialdehyde, soluble sugar, and soluble protein levels. The results indicated that treatment with 1% polyethylene microplastics increased the chlorophyll a, total chlorophyll, and soluble protein contents in the leaves of both types of seedlings while inhibiting superoxide dismutase and peroxidase activities in P. bournei seedlings. Treatment with 2% polyethylene or polypropylene microplastics suppressed the chlorophyll a, chlorophyll b, and total chlorophyll contents; superoxide dismutase, peroxidase, and catalase activities; and soluble sugar and soluble protein levels in the leaves of both types of seedlings, resulting in reduced growth in terms of height and ground-line diameter. The physiological effects of polyethylene microplastics were more evident than those of polypropylene at the same concentration. The results demonstrated that microplastics can affect photosynthesis, the antioxidant system, and osmotic regulation in Chinese fir and P. bournei seedlings, thereby inhibiting their normal growth and development. Exposure to 1% (w/w) microplastics triggered stress responses in seedlings, whereas 2% (w/w) microplastics impeded seedling growth.
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Xanthoceras sorbifolium Bunge is priced for its medical and energetic values. The species also plays a key role in stabilizing ecologically fragile areas exposed to excess soil salinity. In this study, the effects of salinity on the growth, physiological, and photosynthetic parameters of X. sorbifolium Bunge were investigated. The X. sorbifolium seedlings were subjected to five salt treatments: 0 (control, CK), 70, 140, 210, and 280 mM of sodium chloride (NaCl) solutions. NaCl caused a decrease in plant height, specific leaf area, biomass, and root parameters. Leaf wilting and shedding and changes in root morphology, such as root length, root surface area, and root tips were observed. This study found that X. sorbifolium is tolerant to high salinity. Compared with the CK group, even if the concentration of NaCl was higher than 210 mM, the increase of the relative conductivity was also slow, while intercellular CO2 concentration had a similar trend. Moreover, NaCl stress caused an increase in the malondialdehyde (MDA), soluble proteins, and proline. Among the enzymes in the plant, the catalase (CAT) activity increases first and decreased with the increase in the intensity of NaCl stress, but the salt treatment had no significant effect on superoxide dismutase (SOD) activity. The peroxidase (POD) showed an increasing trend under salt stress. It was found that the photosynthesis of X. sorbifolium was notably impacted by saline stress. NaCl toxicity induced a noticeable influence on leaf net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci), transpiration rate (E), and water use efficiency (Wue). As salt concentration increased, the content of chlorophyll decreased. It can be found that a low concentration of NaCl induced the increase of photosynthetic capacity but a high-intensity exposure to stress resulted in the reduction of photosynthetic efficiency and SOD activity, which had a positive correlation. In summary, salt-induced ionic stress primarily controlled root morphology, osmotic adjustment, and enzyme activities of salt-treated X. sorbifolium leaves, whereas the low salt load could, in fact, promote the growth of roots.
RESUMO
Objective @#To analyze the status and influencing factors of the intention of people aged 18 to 25 years to primary medical institutions and their satisfaction for health services in Zhejiang Province, so as to provide basis for the improvement of health services in primary medical institutions.@*Methods@#During November and December in 2019,the 18-25 year-old people in Zhejiang Province were recruited to investigate the general information, intention to seek medical advice and satisfaction for health services in primary medical institutions through WeChat. Logistic regression was performed to analyze the influencing factors of the intention and the satisfaction. Importance matrix was used to analyze the key drivers of the satisfaction. @*Results@#Among the 620 people surveyed, with a response rate of 93.37%, 142 (22.90%) chose primary medical institutions for advice. Actually 516 (83.23%) people went to primary medical institutions last year, and 384 ( 74.42% ) of them were satisfied with the health services. The results of multivariate logistic regression analysis showed that the people aged 18-25 years who were under the new rural cooperative medical care system ( OR=3.062, 95%CI: 1.745-5.373 ) and who had records in community health centers ( OR=0.547, 95%CI: 0.308-0.970 ) were more likely to go to primary medical institutions for medical advice; the ability of doctors ( OR=1.478, 95%CI:1.168-1.871 ) ,the drug notification by medical staff ( OR=1.308, 95%CI: 1.065-1.606 ) , routine examination items ( OR=1.523, 95%CI: 1.227-1.889 ) , the ways of payment ( OR=1.168, 95%CI: 1.017-1.340 ) , the comfort of environment ( OR=1.785, 95%CI: 1.437-2.219 ) and the bulletin boards of health knowledge ( OR=1.302, 95%CI: 1.086-1.561 ) were associated with the satisfaction. The results of importance matrix analysis showed that the ability of doctors and routine examination items were the priorities to improve, followed by the drug notification by medical staff; the comfort of environment had competitive advantages; the ways of payment and the bulletin boards of health knowledge needed to be further analyzed. @*Conclusions@#The 18-25-year-old people in Zhejiang Province were less intended to seek medical advice in primary medical institutions, which was associated with the type of medical insurance and records in community health centers. They were satisfied with the health services, the ability of doctors and routine examination items were the key drivers.
