Evaluation model of urban tourism competitiveness in the context of sustainable development.

In the contemporary context marked by globalization and the growing prominence of sustainable development, assessing urban tourism competitiveness has emerged as a crucial research domain. This paper aims to develop a comprehensive model for evaluating city tourism competitiveness, grounded in the principles of sustainable development. The model incorporates factors such as city tourism resources, environmental considerations, economic aspects, and societal factors. This holistic approach seeks to offer valuable insights for the city tourism industry. The study conducts a thorough analysis of current research both domestically and internationally, highlighting gaps and articulating the objectives and significance of the research. Employing a machine learning-based empowerment method, the paper determines the significance of evaluation indices and utilizes the Topsis method for assessing urban tourism competitiveness. Distinguishing itself from traditional evaluation methods, this model integrates the principles of sustainable development throughout the evaluation process, with environmental, social, and economic sustainability serving as pivotal evaluation indicators. Empirical analysis involves the evaluation of tourism competitiveness for select cities, facilitating inter-city comparisons. Results from empirical studies demonstrate the model's effectiveness in evaluating urban tourism competitiveness, providing targeted developmental recommendations for urban tourism.

Copper-Induced In Vivo Gene Amplification in Budding Yeast.

In the biotechnological industry, multicopy gene integration represents an effective strategy to maintain a high-level production of recombinant proteins and to assemble multigene biochemical pathways. In this study, we developed copper-induced in vivo gene amplification in budding yeast for multicopy gene expressions. To make copper as an effective selection pressure, we first constructed a copper-sensitive yeast strain by deleting the CUP1 gene encoding a small metallothionein-like protein for copper resistance. Subsequently, the reporter gene fused with a proline-glutamate-serine-threonine-destabilized CUP1 was integrated at the δ sites of retrotransposon (Ty) elements to counter the copper toxicity at 100 µM Cu2+. We further demonstrated the feasibility of modulating chromosomal rearrangements for increased protein expression under higher copper concentrations. In addition, we also demonstrated a simplified design of integrating the expression cassette at the CUP1 locus to achieve tandem duplication under high concentrations of copper. Taken together, we envision that this method of copper-induced in vivo gene amplification would serve as a robust and useful method for protein overproduction and metabolic engineering applications in budding yeast.

Pharmacokinetics and Bioequivalence of Amlodipine Besylate Tablet in Healthy Chinese Volunteers Under Fasting and Fed Conditions.

The purpose of this study was to compare the blood concentration and pharmacokinetic (PK) parameters of 2 formulations under fasting and ed conditions in healthy Chinese volunteers and to evaluate whether the 2 preparations were bioequivalent. This trial screened 170 subjects. Thirteen subjects were assigned to the fasting trial and 18 subjects to the fed trial; 1 subject in the fed trial group was automatically withdrawn for personal reasons. Two cycles had a 14-day washout period. This clinical study was a bioequivalence study, with PK parameters as end point indicators. The bioequivalence PK parameters were the maximal concentration (Cmax ), area under the blood drug concentration-time curve from 0 to 72 hours (AUC0-72 h ), and the time to peak plasma concentration (tmax ) which were determined in human plasma by the liquid chromatography-tandem mass spectrometry method, and nonatrioventricular model analysis was used to determine Cmax , AUC0-72 h , tmax , and other PK parameters. The incidence of adverse events was calculated on the basis of System Organ Classification and Preferred Terms. The results showed that the amlodipine besylate tablets met the equivalence range requirements of bioequivalence in the guidelines for human bioavailability and bioequivalence testing under fasting and fed conditions, compared to the fasting test; the tmax of the fed test was almost unchanged; and the Cmax and AUC0-72 h showed no difference between fasting and fed conditions. It was confirmed that both formulations were well tolerated, and no new safety signals were observed.

A Layered Genetic Design Enables the Yeast Galactose Regulon to Respond to Cyanamide.

The commonly used expression systems in Saccharomyces cerevisiae typically rely on either constitutive or galactose-regulated promoters. The lack of inducible systems in S. cerevisiae limits the precise temporal regulation of protein function and yeast metabolism. We herein repurposed the galactose-regulated system to make it respond to cyanamide. By using a cyanamide-inducible DDI2 promoter to control Gal4 expression in CEN.PK2-1C with Δgal80, a tight and graded cyanamide-inducible GAL system with an enhanced signal output was constructed. Subsequently, we demonstrated that the cyanamide-inducible GAL system was capable of tightly regulating the pentafunctional Aro1 protein to achieve conditional shikimate pathway activity. Taken together, the cyanamide-inducible GAL system could be implemented for both fundamental research and applied biotechnology.

The dynamics of income-related health inequality among American children.

We estimate and decompose income-related inequality in child health in the USA and analyze its dynamics using the recently introduced health mobility index. Data come from the 1997, 2002, and 2007 waves of the Child Development Supplement of the Panel Study of Income Dynamics. The findings show that income-related child health inequality remains stable as children grow up and enter adolescence. The main factor underlying income-related child health inequality is income itself, although other factors, such as maternal education, also play a role. Decomposition of income-related health mobility indicates that health changes over time are more favorable to children with lower initial family incomes versus children with higher initial family incomes. However, offsetting this effect, our findings also suggest that changes in income ranking over time are positively related to children's subsequent health status.