Inequity in the access to and deployment of the coronavirus disease 2019 (COVID-19) vaccines has brought about great challenges in terms of resolving the pandemic. Aiming to analyze the association between country income level and COVID-19 vaccination coverage and explore the mediating role of vaccination policy, we conducted a cross-sectional ecological study. The dependent variable was COVID-19 vaccination coverage in 138 countries as of May 31, 2021. A single-mediator model based on structural equation modeling was developed to analyze mediation effects in different country income groups. Compared with high-income countries, upper-middle- (β = −1.44, 95% CI: −1.86–−1.02, p < 0.001), lower-middle- (β = −2.24, 95% CI: −2.67–−1.82, p < 0.001), and low- (β = −4.05, 95% CI: −4.59–−3.51, p < 0.001) income countries had lower vaccination coverage. Vaccination policies mediated 14.6% and 15.6% of the effect in upper-middle- (β = −0.21, 95% CI: −0.39–−0.03, p = 0.020) and lower-middle- (β = −0.35, 95% CI: −0.56–−0.13, p = 0.002) income countries, respectively, whereas the mediation effect was not significant in low-income countries (β = −0.21, 95% CI: −0.43–0.01, p = 0.062). The results were similar after adjusting for demographic structure and underlying health conditions. Income disparity remains an important cause of vaccine inequity, and the tendency toward “vaccine nationalism” restricts the functioning of the global vaccine allocation framework. Stronger mechanisms are needed to foster countries’ political will to promote vaccine equity.

In this communication, a laminated, flexible, microfluidic-integrated, all CNT based liquid-gated transistor and biosensor are reported that comprises single walled CNTs for both the semiconducting channel as well as the contact electrodes. The proposed architecture eliminates the need for lithography, electrode definition processes, and also circumvents substrate surface compatibility issues. Real-time detection of 1 pM poly-L-lysine in a liquid-gated transistor comprising only two materials, single walled CNTs and polydimethoxysilane substrate with microfluidic channel, is demonstrated.

In this paper, three different kinds of steel fibers, being micro (M), end-hooked (H), and corrugated (C), commonly used in engineering applications, are added to high-strength lightweight aggregate concrete (HLAC) to study the effects of steel fiber and volume content ratio of fiber on the compressive, splitting tensile, and flexural strength of HLAC. The range of steel fiber volume content fraction studied is 0.5% to 2.0%. The research shows that different types of steel fiber have different effects on the mechanical properties and toughness of HLAC. M steel fibers have the best reinforcing performance on the mechanical properties. The study also shows that the toughness of M steel fibers is the best with the same fiber content. The toughening effect of H and C steel fibers can only reach 2/3 and 1/2 of M steel fibers, respectively. At the end of this paper, the unified strength formula and toughness index of these three kinds of high-strength steel fiber lightweight aggregate concrete (HSLAC) with different fiber contents are given to provide a reference for engineering practice and design.

Background Ischemic heart disease causes a high disease burden globally and numerous challenges in treatment, particularly in developing countries such as China. The National Chest Pain Centers Program (NCPCP) was launched in China as the first nationwide, hospital-based, comprehensive, continuous quality improvement (QI) program to improve early diagnosis and standardized treatment of acute coronary syndromes (ACS) and improve patients’ clinical outcomes. With implementation and scaling up of the NCPCP, we investigated barriers and enablers in the NCPCP implementation process and provided examples and ideas for overcoming such barriers. Methods We conducted a nationally representative survey in six cities in China. A total of 165 key informant interviewees, including directors and coordinators of chest pain centers (CPCs) in 90 hospitals, participated in semi-structured interviews. The interviews were transcribed verbatim, translated into English, and analyzed in NVivo 12.0. We used the Consolidated Framework for Implementation Research (CFIR) to guide the codes and themes. Results Barriers to NCPCP implementation mainly arose from nine CFIR constructs. Barriers included the complexity of the intervention (complexity), low flexibility of requirements (adaptability), a lack of recognition of chest pain in patients with ACS (patient needs and resources), relatively low government support (external policies and incentives), staff mobility in the emergency department and other related departments (structural characteristics), resistance from related departments (networks and communications), overwhelming tasks for CPC coordinators (compatibility), lack of available resources for regular CPC operations (available resources), and fidelity to and sustainability of intervention implementation (executing). Enablers of intervention implementation were inner motivation for change (intervention sources), evidence strength and quality of intervention, relatively low cost (cost), individual knowledge and beliefs regarding the intervention, pressure from other hospitals (peer pressure), incentives and rewards of the intervention, and involvement of hospital leaders (leadership engagement, engaging). Conclusion Simplifying the intervention to adapt routine tasks for medical staff and optimizing operational mechanisms between the prehospital emergency system and in-hospital treatment system with government support, as well as enhancing emergency awareness among patients with chest pain are critically important to NCPCP implementation. Clarifying and addressing these barriers is key to designing a sustainable QI program for acute cardiovascular diseases in China and similar contexts across developing countries worldwide. Trial registration This study was registered in the Chinese Clinical Trial Registry (ChiCTR 2100043319), registered 10 February 2021.

Cobalt/Palladium (Co/Pd) multilayer film and nanodisc samples were fabricated on polyethylene terephthalate (PET) substrates. The effects of surface roughness and grain size of PET substrate, the Co/Pd layer and the Au intermediate layer on the magnetic properties of these samples were investigated. We observed that the coercivity for Co/Pd films deposited directly on a smoother PET substrate is significantly smaller when compared with Co/Pd films deposited at the same time on Au buffer layer. The patterned Co/Pd nanodisc array exhibited a larger coercivity than the corresponding continuous film due to lower probability of finding nucleation sites in reduced film area.