ABSTRACT
Labor and water scarcity requires crop establishment of double-season rice to be shifted from traditional transplanting to direct seeding. Owing to the limited thermal time, only ultrashort-duration cultivars of about 95 d can be used for direct-seeded, double-season rice (DDR) in central China. However, whether the shift in crop establishment of double-season rice can reduce greenhouse gas emissions without yield penalty remains unclear. Field experiments were conducted in Hubei province, central China with three treatments of crop establishment in the early and late seasons of 2017 and 2018. Treatments included DDR with ultrashort-duration cultivars (DDRU), transplanted double-season rice with ultrashort-duration cultivars (TDRU), or with widely grown cultivars which have short duration of about 110 d (TDRS). It was found that crop growth duration of DDRU was 6-20 days shorter than that of TDRU and TDRS, respectively. Ultrashort-duration cultivars under DDRU achieved 15.1 t ha-1 of annual yield that was 9.4% higher than TDRU, and only 3.2% lower than TDRS. DDRU reduced the annual cumulative CH4 emission by 32.0-46.1%, but had no difference in N2O emission in comparison with TDRU and TDRS. The highest CO2 emission was TDRS followed by DDRU, and then TDRU. As a result, shifting from TDRU and TDRS to DDRU decreased global warming potential and yield-scaled greenhouse gas intensity by 28.9-53.2% and 20.7-63.8%, respectively. These findings suggest that DDR can be a promising alternative to labor- and water-intensive TDR in central China that offers important advantages in mitigating agricultural greenhouse gas emissions without sacrificing grain yield.
ABSTRACT
OBJECTIVE：To systematically evaluate the research and development status quo of respiratory inhalation preparations. METHODS ：Related literatures or data about R&D status quo of domestic and foreign respiratory inhalation preparations were retrieved from 5 databases（PubMed，Embase，CNKI，Wanfang database and VIP ），4 clinical trial registration platforms，15 national/regional drug administration platforms and yaozhi.com . The status quo of related studies was analyzed by descriptive analysis. RESULTS & CONCLUSIONS ：A total of 27 second literatures were included. The information of respiratory inhalation preparations approved by European Union ，the United States ，Canada，Japan and China was collected ，and the information of related drugs under registration and approval in China was also collected. The market situation of respiratory inhalation preparations was analyzed from the perspective of dosage form ：powder aerosols accounted for 46％，aerosols account ed for 32％，and atomized inhalation solutions accounted for 22％ in the global consumption sum of each dosage form. From the perspective of market share ，companies such as AstraZeneca in the UK ，Boehringer Ingelheim in Germany and GlaxoSmithKline in the UK had a total market share of about 70％. At present ，there were 39 kinds of respiratory inhalation preparations on the market in European Union ，121 kinds in the United States ，111 kinds in Canada ，37 kinds in Japan ，69 kinds of domestic inhalation preparations and 80 kinds of imported inhalation preparations in China. Respiratory inhalation preparations were undergoing clinical trials with 511 cases abroad and 69 cases in China. The barriers to the imitation of respiratory inhalation preparations mainly included research and development ，clinical trial ，approval and production barriers. At present ，the support is provided for 0035） domestic drug innovation and localization of medical devices in China through a series of policies ，which is helpful to promote the localization research and development of inha led preparations. Future research and development can pay more cn attention to combination ，indication，dosage and device of inhalation preparation.
