RESUMO
Pu'er tea is a Yunnan geographical indication product, and its brand value ranks first in China. At present, qualitative and quantitative methods with low prediction accuracy are used to predict price. In this paper, based on the current situation and industry characteristics, a differential autoregressive integrated moving average model (ARIMA) is used to predict the short-term price. From the perspective of macro and micro, back-propagation neural network model (BP) was established to predict the long-term price based on the weight ranking of 16 factors affecting the price by technique for order preference by similarity to ideal solution method (TOPSIS). The future price is predicted and analyzed, and then based on the empirical results, suggestions are put forward for the industry in terms of reducing production capacity, increasing consumer demand and combining with the publicity and promotion of Internet.
RESUMO
An organic-inorganic hybrid silver iodobismuthate characteristic of the infrequent [Ag2BiI6L2] cluster (L = I or I3) and with a unique Ag/Bi molar ratio (2/1), namely, [Zn(bipy)3]2Ag2BiI6(I)1.355(I3)1.645 (bipy = 2,2'-bipyridine; 1), was solvothermally synthesized, and structurally, optically, and theoretically studied. Intriguingly, compound 1 exhibited semiconductor behavior with an optical band gap of 2.33 eV, which endowed it with excellent photoelectric and photocatalytic properties. Electronic structure calculations further revealed that the relative separate conduction band (CB) and valence band (VB) in compound 1 may be responsible for the good optical activity. This study also includes the Hirshfeld surface analyses, thermogravimetric measurements and X-ray photoelectron spectroscopy (XPS) characterization.
RESUMO
BACKGROUND: Children as a population have high antimicrobial prescribing rates which may lead to high resistance of bacteria according to data from some single-center surveys of antibiotic prescribing rates in China. The acquirement of baseline data of antibiotic prescribing is the basis of developing intervention strategies on inappropriate antimicrobial prescriptions. Few studies show clearly the pattern and detailed information on classes of antibiotics and distribution of indications of antibiotic prescriptions in children in China. This study aims to assess the antibiotic prescribing patterns among children and neonates hospitalized in 18 hospitals in China. METHODS: A 24-hour point prevalence survey on antimicrobial prescribing was conducted in hospitalized neonates and children in China from December 1st, 2016 to February 28th, 2017. Information on the antibiotic use of patients under 18 years of age who were administered one or more on-going antibiotics in the selected wards over a 24-hour period was collected. These data were submitted to the GARPEC (Global Antimicrobial Resistance, Prescribing and Efficacy in Children and Neonates) web-based application ( https://pidrg-database.sgul.ac.uk/redcap/ ). For statistical analysis, Microsoft Excel 2007 and SPSS 22.0 were used. RESULTS: The antibiotic data were collected in 35 wards in 18 hospitals from 9 provinces. In total, 67.76% (975/1439) of the patients (n = 1439) were given at least one antibiotic, including 58.1% (173/298) of neonates (n = 298) and 70.3% (802/1141) of children (n = 1141). In neonates, the three most frequently prescribed antibiotics were third-generation cephalosporins (41.7%), penicillins plus enzyme inhibitor (23.8%), and carbapenems (11.2%). In children, the three most frequently prescribed antibiotics were third-generation cephalosporins (35.5%), macrolides (23.2%), and penicillins plus enzyme inhibitors (15.9%). The most common indication for antibiotics was proven or probable bacterial lower respiratory tract infection (30.9% in neonates and 66.6% in children). CONCLUSIONS: Antibiotics are commonly prescribed in the Chinese children population. It is likely that the third-generation cephalosporins and macrolides are currently overused in Chinese children. Efforts must be made to ensure safe and appropriate antibiotic prescribing to reduce and prevent the future development of antibiotic resistance.