Spatial patterns and influencing factors of financial agglomeration in Guangdong-Hong Kong-Macao Greater Bay Area.

The Guangdong-Hong Kong-Macao Greater Bay Area (GBA) represents a significant economic zone with a diverse financial landscape. Understanding the spatial distribution of financial resources within this area is crucial for promoting balanced economic growth and financial development. This study investigates the spatial patterns of financial agglomeration in the GBA, identifying key influencing factors and assessing their impact on the region's financial landscape. We employ the entropy value method to evaluate financial agglomeration levels across the GBA's cities. Additionally, we use spatial econometric techniques to analyze the spatial correlations and the Geo-Detector model to determine the primary factors influencing financial agglomeration. The analysis reveals an overall increase in financial agglomeration, with significant disparities among cities. Key factors driving this agglomeration include transportation infrastructure, overseas trade, foreign direct investment (FDI), and technological advancements. Hong Kong and Shenzhen display notable unevenness in the distribution of financial industries. The interplay between finance, technology, and industrial sectors suggests considerable development potential. Understanding and optimizing the spatial distribution of financial resources is essential for fostering high-quality financial development and sustainable economic growth in the GBA. This study provides insights that can inform policy decisions aimed at enhancing financial integration and cooperation within the region.

COVID-19 prevention and control in China: grid governance.

The coronavirus disease 2019 (COVID-19) pandemic has spread worldwide and caused negative economic and health effects. China is one of the most seriously affected countries, and it has adopted grid governance measures at the basic level of society, which include city lockdown, household survey and resident quarantine. By the end of April, China had basically brought the pandemic under control within its own borders, and residents' lives and factory production gradually began to return to normal. In referring to the specific cases of different communities, schools, and enterprises in the four cities of Anhui, Beijing, Shenzhen and Zibo, we analyze grid-based governance measures and we summarize the effectiveness and shortcomings of these measures and discuss foundations and future challenges of grid governance. We do so in the expectation (and hope) that the world will gain a comprehensive understanding of China's situation and introduce effective measures that enable the prevention and control of COVID-19.

Optimum induction of recombinant thymidine phosphorylase and its application.

Recombinant E. coli pDEOA was constructed and lactose can be used instead of IPTG to induce the expression of thymidine phosphorylase by pDEOA. The use of lactose at concentrations higher than 0.5 mmol/L had an induction effect similar to that of IPTG but resulted in a longer initial induction time and better cell growth. The thymidine phosphorylase induced by lactose was very stable at 50°C. Intact pDEOA cells induced by lactose can be used as a source of thymidine phosphorylase. Under standard reaction conditions, several deoxynucleosides were effectively produced from thymidine.

Enzymatic synthesis of nucleosides by nucleoside phosphorylase co-expressed in Escherichia coli.

Nucleoside phosphorylase is an important enzyme involved in the biosynthesis of nucleosides. In this study, purine nucleoside phosphorylase and pyrimidine nucleoside phosphorylase were co-expressed in Escherichia coli and the intact cells were used as a catalyst for the biosynthesis of nucleosides. For protein induction, lactose was used in place of isopropyl ß-D-1-thiogalactopyranoside (IPTG). When the concentration of lactose was above 0.5 mmol/L, the ability to induce protein expression was similar to that of IPTG. We determined that the reaction conditions of four bacterial strains co-expressing these genes (TUD, TAD, DUD, and DAD) were similar for the biosyntheses of 2,6-diaminopurine nucleoside and 2,6-diaminopurine deoxynucleoside. When the substrate concentration was 30 mmol/L and 0.5% of the recombinant bacterial cell volume was used as the catalyst (pH 7.5), a greater than 90% conversion yield was reached after a 2-h incubation at 50 °C. In addition, several other nucleosides and nucleoside derivatives were efficiently synthesized using bacterial strains co-expressing these recombinant enzymes.

Induction of nucleoside phosphorylase in Enterobacter aerogenes and enzymatic synthesis of adenine arabinoside.

Nucleoside phosphorylases (NPases) were found to be induced in Enterobacter aerogenes DGO-04, and cytidine and cytidine 5'-monophosphate (CMP) were the best inducers. Five mmol/L to fifteen mmol/L cytidine or CMP could distinctly increase the activities of purine nucleoside phosphorylase (PNPase), uridine phosphorylase (UPase) and thymidine phosphorylase (TPase) when they were added into medium from 0 to 8 h. In the process of enzymatic synthesis of adenine arabinoside from adenine and uracil arabinoside with wet cells of Enterobacter aerogenes DGO-04 induced by cytidine or CMP, the reaction time could be shortened from 36 to 6 h. After enzymatic reaction the activity of NPase in the cells induced remained higher than that in the cells uninduced.