Knowledge domain and emerging trends in sacubitril/valsartan study from 2008 to 2023 - a visualized conclusive analysis based on novel scientometric tools.

OBJECTIVE: This study aimed to determine the evolution of sacubitril-valsartan research and analyze the publications quantitatively and qualitatively. MATERIALS AND METHODS: We used the bibliometric method and a combination of CiteSpace_6.1.6 and VOSviewer_1.6.18 to identify top authors, countries, institutions, co-cited articles, co-cited journals, keywords, and trends. This study prioritized key aspects in the existing global research on Entresto (Sacubitril/Valsartan) to assess our depth of knowledge in this field and identify potential insights. The objective was to generate a reference for the utilization of the "angiotensin receptor-neprilysin inhibitor" (ARNI). RESULTS: From 2008 to 2022, citations of sacubitril-valsartan showed an upward trend. VOSviewer keyword analysis of 3,408 publications identified 624 keywords and divided them into seven different clusters. The clustered network was constructed based on 1,191 references cited by 3,408 publications that met the terms, where the clustered network of sacubitril-valsartan was presented. These publications can be regarded as fundamental to Entresto's research. Analysis of co-cited reference clusters showed that other than Entresto's novel application in other diseases, the new combination with other medication or mechanical assistance therapies against heart failure was Entresto's latest focus. Analysis of citation bursts showed that the rank of the top 25 keywords, according to the chronological sequence, marked Entresto's research entering a new era of exploring the extended application in other diseases and novel combinations with other diverse therapies. CONCLUSIONS: We found that emerging new mechanisms in sacubitril-valsartan therapy intended for more targets in the pathogenesis of specific diseases will be the focus of further studies.

Genetic and physiological studies of Bacillus subtilis sigma A mutants defective in promoter melting.

The Bacillus subtilis sigA gene encodes the primary sigma factor of RNA polymerase and is essential for cell growth. We have mutated conserved region 2.3 of the sigma A protein to substitute each of seven aromatic amino acids with alanine. Several of these aromatic amino acids are proposed to form a melting motif which facilitates the strand separation step of initiation. Holoenzymes containing mutant sigma factors recognize promoters, but some are defective for DNA melting in vitro. We have studied the ability of each mutant sigma factor to support cell growth by gene replacement and complementation. The two region 2.3 mutants least impaired in promoter melting in vitro (Y180A and Y184A) support cell growth in single copy, although the Y184A allele imparts a slow-growth phenotype at low temperatures. A strain expressing only the Y189A variant of the sigma A protein, known to be defective in DNA melting in vitro, grows very slowly and is altered in its pattern of protein synthesis. Only the wild-type and Y180A sigma A proteins efficiently complement a temperature-sensitive allele of sigA. Overexpression of three of the sigma A proteins defective for promoter melting in vitro (Y189A, W192A, and W193A) leads to a decrease in RNA synthesis and cell death. These results indicate that mutations which specifically impair DNA melting in vitro also impair sigma function in vivo and therefore support the hypothesis that sigma plays an essential role in both DNA melting and promoter recognition.