Impact of perceived ease of use, organizational support mechanism, and industry competitive pressure on physicians’ use of liver cancer screening technology in medical alliances

Background: Liver cancer is one of the malignant tumors worldwide, while the prevention and control situation is grim at present, and the diffusion of its early screening technology still faces some challenges. This study aims to investigate the influencing mechanism of perceived ease of use, organizational support mechanism, and industry competitive pressure on hepatic early screening technologies use by physicians, so as to promote the wider use of corresponding technologies. Methods: Under the theoretical guidance of technology-organization-environment framework and mindsponge theory, this study took hepatic contrast-enhanced ultrasound as an example, and conducted a cross-sectional questionnaire by randomly selecting physicians from Fujian and Jiangxi provinces in China with a high and low incidence of liver cancer, respectively. Structural equation modeling was used to determine the correlation among perceived ease of use, organizational support mechanism, and industry competitive pressure, as well as their impact on the physicians’ behavior toward contrast-enhanced ultrasound use. Results: The hypothesis model fits well with the data (χ2/df = 1.863, GFI = 0.937, AGFI = 0.908, RMSEA = 0.054, NFI = 0.959, IFI = 0.980, CFI = 0.980). Under technology-organization-environment framework, the perceived ease of use (β = 0.171, p \u3c 0.05), organizational support mechanism (β = 0.423, p \u3c 0.01), industry competitive pressure (β = 0.159, p \u3c 0.05) significantly influenced physicians’ use of hepatic contrast-enhanced ultrasound. Besides, perceived ease of use and organizational support mechanism (β = 0.216, p \u3c 0.01), perceived ease of use and industry competitive pressure (β = 0.671, p \u3c 0.01), organizational support mechanism and industry competitive pressure (β = 0.330, p \u3c 0.01) were all associated significantly. Conclusion: From the lens of information processing (mindsponge theory) and technology-organization-environment framework, this study clarified the social and psychological influencing mechanism of perceived ease of use, organizational support mechanism, and industry competitive pressure on physicians’ use of hepatic contrast-enhanced ultrasound. The results will directly propose recommendations for expanding hepatic contrast-enhanced ultrasound utilization and indirectly promoting other appropriate and effective health technologies diffusion within the integrated health system

Delineating the biosynthesis of gentamicin x2, the common precursor of the gentamicin C antibiotic complex.

Gentamicin C complex is a mixture of aminoglycoside antibiotics used worldwide to treat severe Gram-negative bacterial infections. Despite its clinical importance, the enzymology of its biosynthetic pathway has remained obscure. We report here insights into the four enzyme-catalyzed steps that lead from the first-formed pseudotrisaccharide gentamicin A2 to gentamicin X2, the last common intermediate for all components of the C complex. We have used both targeted mutations of individual genes and reconstitution of portions of the pathway in vitro to show that the secondary alcohol function at C-3″ of A2 is first converted to an amine, catalyzed by the tandem operation of oxidoreductase GenD2 and transaminase GenS2. The amine is then specifically methylated by the S-adenosyl-l-methionine (SAM)-dependent N-methyltransferase GenN to form gentamicin A. Finally, C-methylation at C-4″ to form gentamicin X2 is catalyzed by the radical SAM-dependent and cobalamin-dependent enzyme GenD1.This work was supported by a project grant from the Medical Research Council, UK (G1001687) to P.F.L.; and by the 973 and 863 programs from the Ministry of Science and Technology of China, National Science Foundation of China, and the Translational Medical Research Fund of Wuhan University School of Medicine to Y.S.; E.M. thanks the Gates Cambridge Trust for a scholarship. We also gratefully acknowledge Dr. Xinzhou Yang, SouthCentral University for Nationalities, for his assistance in separation of gentamicin A2. We thank Dr. Andrew Truman (John Innes Institute) for helpful discussions.This is the final published version. It was originally published in Chemistry and Biology, Volume 22, Issue 2, 19 February 2015, Pages 251–261, doi:10.1016/j.chembiol.2014.12.01

Methyltransferases of gentamicin biosynthesis

Gentamicin C complex from Micromonospora echinospora remains a globally important antibiotic, and there is revived interest in the semisynthesis of analogs that might show improved therapeutic properties. The complex consists of five components differing in their methylation pattern at one or more sites in the molecule. We show here, using specific gene deletion and chemical complementation, that the gentamicin pathway up to the branch point is defined by the selectivity of the methyltransferases GenN, GenD1, and GenK. Unexpectedly, they comprise a methylation network in which early intermediates are ectopically modified. Using whole-genome sequence, we have also discovered the terminal 6'-N-methyltransfer required to produce gentamicin C2b from C1a or gentamicin C1 from C2, an example of an essential biosynthetic enzyme being located not in the biosynthetic gene cluster but far removed on the chromosome. These findings fully account for the methylation pattern in gentamicins and open the way to production of individual gentamicins by fermentation, as starting materials for semisynthesis.This work was supported by National Natural Science Foundation of China Grant 31470186; by the 973 Program Grant 2012CB721005 from the Ministry of Science and Technology of China; by Open Project Grant MMLKF15-12 from the State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University (to Y.S.); by Medical Research Council (MRC) Grants G1001687 and MR/M019020/1 (to P.F.L.); and by an MRC postgraduate studentship (1343325) (to A.R.)

Runoff and Sediment Response to Cascade Hydropower Exploitation in the Middle and Lower Han River, China

With the rapid development of hydropower exploitation in China, changes in runoff and sediment transport have become a significant issue that cannot be neglected. In this study, the Han River was selected as a study case, where the runoff variation and changes in sediment load at the Baihe, Huangjiagang, Huangzhuang, and Xiantao stations were analyzed in different time periods. The results indicate that impact of cascade hydropower exploitation on runoff and sediment transport is significantly different even during the same time periods. After reservoir regulation, the decreasing of sediment load is faster than that of runoff. Strong positive correlation between runoff and sediment load exists during different time periods, while reservoir operation leads to different turning points at the Baihe, Huangjiagang, Huangzhuang, and Xiantao stations in the middle and lower Han River. As a key driving factor, runoff variation contributed to sediment transport with different impact index CR. The impact index CR before and after the first change point at the Baihe, Huangjiagang, Huangzhuang, and Xiantao stations is 43.35%, −3.68%, 11.17%, and 30.12%, respectively. This study helps us understand and evaluate the hydrological changes under cascade hydropower exploitation in the middle and lower Han River

A Dielectric Metasurface Optical Chip for the Generation of Cold Atoms

Compact and robust cold atom sources are increasingly important for quantum research, especially for transferring cutting-edge quantum science into practical applications. In this letter, we report on a novel scheme that utilizes a metasurface optical chip to replace the conventional bulky optical elements used to produce a cold atomic ensemble with a single incident laser beam, which is split by the metasurface into multiple beams of the desired polarization states. Atom numbers $~10^7$ and temperatures (about 35 ${\mu}$K) of relevance to quantum sensing are achieved in a compact and robust fashion. Our work highlights the substantial progress towards fully integrated cold atom quantum devices by exploiting metasurface optical chips, which may have great potential in quantum sensing, quantum computing and other areas