Chirality Supramolecular Systems: Helical Assemblies, Structure Designs, and Functions.

Chirality, as one of the most striking characteristics, exists at various scales in nature. Originating from the interactions of host and guest molecules, supramolecular chirality possesses huge potential in the design of functional materials. Here, an overview of the recent progress in structure designs and functions of chiral supramolecular materials is present. First, three design routes of the chiral supramolecular structure are summarized. Compared with the template-induced and chemical synthesis strategies that depend on accurate molecular identification, the twisted-assembly technique creates chiral materials through the ordered stacking of the nanowire or films. Next, chirality inversion and amplification are reviewed to explain the chirality transfer from the molecular level to the macroscopic scale, where the available external stimuli on the chirality inversion are also given. Lastly, owing to the optical activity and the characteristics of the layer-by-layer stacking structure, the supramolecular chirality materials display various excellent performances, including smart response, shape-memorization, superior mechanical performance, and applications in biomedical fields. To sum up, this work provides a systematic review of the helical assemblies, structure design, and applications of supramolecular chirality systems.

Uncovering the Recent Progress of CNC-Derived Chirality Nanomaterials: Structure and Functions.

Cellulose nanocrystal (CNC), as a renewable resource, with excellent mechanical performance, low thermal expansion coefficient, and unique optical performance, is becoming a novel candidate for the development of smart material. Herein, the recent progress of CNC-based chirality nanomaterials is uncovered, mainly covering structure regulations and function design. Undergoing a simple evaporation process, the cellulose nanorods can spontaneously assemble into chiral nematic films, accompanied by a vivid structural color. Various film structure-controlling strategies, including assembly means, physical modulation, additive engineering, surface modification, geometric structure regulation, and external field optimization, are summarized in this work. The intrinsic correlation between structure and performance is emphasized. Next, the applications of CNC-based nanomaterials is systematically reviewed. Layer-by-layer stacking structure and unique optical activity endow the nanomaterials with wide applications in the mineralization, bone regeneration, and synthesis of mesoporous materials. Besides, the vivid structural color broadens the functions in anti-counterfeiting engineering, synthesis of the shape-memory and self-healing materials. Finally, the challenges for the CNC-based nanomaterials are proposed.

Advances in metabolism pathways of theaflavins: digestion, absorption, distribution and degradation.

Theaflavins, a major kind of component in black tea, have been reported to show a variety of biological activities and health effects. However, the unstable chemical properties, low bioavailability and unclear metabolism pathways of theaflavins have left much to be desired in terms of its specific efficacy and applications. This paper provides a comprehensive knowledge on the digestion, absorption, metabolism, distribution and excretion of theaflavins. We find that pH-dependent stability, efflux transport proteins are closely related to the low absorption rate and low bioavailability of theaflavins. When pass through the gastrointestinal tract, TFDG, TF2A and TF2B are gradually degraded to TF1, and release gallic acid. Then, the theaflavins skeleton are degraded into small molecular phenolic substances under the action of enzymes and microorganisms. In addition, theaflavins are widely distributed in the human body including brain, lung, heart, kidney, liver, blood tissue in a low content and can be excreted through feces. However, the influence of digestive enzymes barrier and gut microbial barrier on theaflavins are still unclear. Importantly, most findings are reported by in vitro methods and animal experiments, the metabolites and metabolic pathways of theaflavins in human body are not fully understood and need to be further investigated. We hope to lay a theoretical basis for exploring methods to improve the bioavailability of theaflavins and expanding the application of theaflavins in health foods as well as pharmaceuticals.

Factors associated with the choice of primary treatment at the community level among the middle-aged and elderly in China.

BACKGROUND: As China is still in the process of establishing the hierarchical medical system, people have full autonomy in choosing medical institutions when they need to see a doctor. The basic working of a hierarchical medical system involves four parts: primary treatment at the community level, two-way referral, a partition of emergency and chronic disease, and a joint effort among different healthcare facilities. This study examines factors associated with primary healthcare use in a middle-aged and elderly Chinese population. METHODS: Our study is a cross-sectional and observational survey involving 1659 adults aged 45 and above. The data are from the 2015 China Health and Retirement Longitudinal Study. According to the Andersen behavioral model, we used logistic regression to analyze the influencing factors of healthcare services utilization, including predisposing, enabling, and need factors. We also compared the relative importance of factors to healthcare services utilization by analysis of variance. RESULTS: During the recently 1-month period, 63.89% of the sample had their last visit to a primary healthcare facility. In the final logistic model, there were three predisposing characteristics (education level, children number, and work status), three enabling factors (household status, out-of-pocket expenses, and travel time to the healthcare facilities), and one need factor (three specific chronic diseases) were significantly associated with primary healthcare use. Having received more education, taking more travel time to the healthcare facility, paying more out-of-pocket expenses, and having heart problems were associated with a lower probability of choosing the primary healthcare facility. However, having more children, being still at work, with agricultural household status, diabetes, and arthritis were associated with a higher likelihood of having primary healthcare facility visits. Among all the factors, the three most powerful determinants were out-of-pocket expenses, travel time to the healthcare facility, and education. CONCLUSIONS: Policymakers need to consider these factors when improving the system of primary treatment at the community level, including improving reimbursement policy to distinguish the payment standard between hospitals and primary healthcare facilities.

Potential anti-hyperglycemic activity of black tea theaflavins through inhibiting α-amylase.

Hyperglycemia can cause early damage to human bady and develop into diabates that will severely threaten human healthy. The effectively clinical treatment of hyperglycemiais is by inhibiting the activity of α-amylase. Black tea has been reported to show inhibitory effect on α-amylase and can be used for hyperglycemia treatment. However, the mechanism underlying is unclear. In this study, in vivo experiment showed that black tea theaflavins extract (BTE) effectively alleviated hyperglycemia. In vitro experiment showed that the effects may be caused by the interation between theaflavins and α-amylase. While TF1 and TF3 were mixed type inhibitors of α-amylase, TF2A and TF2B were competitive inhibitors of α-amylase. Molecular docking analysis showed that theaflavins monomers interacted with the hydrophobic region of α-amylase. Further study verified that monomer-α-amylase complex was spontaneously formed depending on hydrophobic interactions. Taken together, theaflavins showed potential anti-hyperglycemia effect via inhibiting α-amylase activity. Our results suggested that theaflavins might be utilized as a new type of α-amylase inhibitor to prevent and cure hyperglycemia.

Highly Flexible and Reversible Stimuli-Responsive Photonic Crystal Film in Anti-Counterfeit, Detector, and Coating.

Various fascinating optical characteristics in organisms encourage scientists to develop biomimetic synthesis strategies and mimic their unique microstructure. Inspired by the Chameleon's skin with tunable color and superior flexibility, this work designs the evaporated-induced self-assembly technique to synthesize the chiral photonic crystal film. Ultrasonic-intensified and additive-assisted techniques synergistically optimize the film properties, on the aspects of optic and mechanic. The film shows considerable rigidity and superior flexibility, which can undergo multiple mechanical deformations. Without destroying the chiral nematic structure, the ultimate strain approaches 50%, which exceeds most cellulose-derived film materials. It also integrates excellent optical performance. The film color can cover the total visible region by tuning the photonic bandgap and has angle-dependent properties. It can make the response to humidity and solvents, and chromaticity variation reflects the degree of stimulation. Importantly, this structural-dependent color change is reversible. Lastly, the photonic crystal materials with excellent mechanics and unique optics have been applied in the security. The anti-counterfeiting material design contains photonic crystal ink, repeatable writing paper, information-hiding film, and color-changing labels, with the features of environmentally friendly, economical, non-destructive, and convenient for authentication.

Impact of the COVID-19 pandemic on clinical trials: a cross-sectional questionnaire study in China.

Background: The number of Chinese clinical trials has continued to grow throughout the coronavirus disease 2019 (COVID-19) pandemic, but we know little about clinical trial team members' perceptions and attitudes toward the impacts of the pandemic. This study aimed to assess the impact of the COVID-19 pandemic on clinical trials in China from the perspective of research staff to provide a deeper understanding and some recommendations for the ongoing and upcoming clinical trials during the pandemic. Methods: A nationwide cross-sectional questionnaire was distributed to respondents throughout mainland China between September 2021 and October 2021. The participants assessed the impact of the COVID-19 pandemic on clinical trials based on a 5-point Likert-type scale, and exploratory factor analysis (EFA) was used to confirm the factor structure. Descriptive statistical analysis and the Mann-Whitney test were used to discover the differences between different groups. Results: A total of 2,393 questionnaires from 272 hospitals were collected in mainland China. Factor analysis resulted in 4 factors, with a cumulative explained variance of 64.93%, as follows: subject enrollment, patient care, study supplies and data management, and research milestones and quality management. The research team members, predominantly represented by clinical research coordinators (CRCs), basically agreed with all but 3 preset scenarios of the impact of COVID-19 on clinical trials. Most respondents did not agree that the pandemic was associated with more serious adverse events (SAEs), missed reports of safety events, or any increase of unscheduled unblinding. In addition, significant differences were revealed in different age, gender, and role groups of respondents based on their views on the impact of the pandemic. Conclusions: The current pandemic situation has had a negative impact on clinical trials, especially in terms of subject recruitment and protocol compliance, yet research team members feel confident that some of the effective measures proposed in the study can moderate the negative impact.

Impact of the national drug price negotiation policy on the utilization, cost, and accessibility of anticancer medicines in China: A controlled interrupted time series study.

Background: China implemented the national drug price negotiation (NDPN) policy to include 17 innovative anticancer medicines in the national reimbursement drug list in 2018. We aimed to assess the impact of this policy on the utilization, cost, and accessibility of anticancer medicines. Methods: We obtained monthly medicine procurement data from 1039 hospitals from October 2017 to December 2019. We examined changes in availability, utilization, defined daily dose cost (DDDc), and affordability of the medicines using descriptive statistics and controlled interrupted time series analysis, measuring utilization by defined daily doses (DDDs). Cetuximab and raltitrexed were compared separately for the same indication. Results: The mean availability of 17 negotiated anticancer medicines was 28.78% after the NDPN, amounting to an increase of 25.22%. The availability increased by 7.88% (95% confidence interval (CI) = 4.31%, 11.45%, P < 0.001) immediately and by 1.23% (95% CI = 0.81%, 1.64%, P < 0.001) per month after policy implementation. Compared with the control group, the utilization of the medicines increased by 11.44 DDDs (95% CI = 2.42, 20.46, P = 0.014) immediately and by 3.54 DDDs (95% CI = 2.47, 4.60, P < 0.001) per month after policy implementation, while the DDDc decreased by US$109.09 (95% CI = 68.14, 150.05, P < 0.001) immediately and remained stable thereafter. The results on cetuximab and raltitrexed were similar. Availability and utilization differed among regions in east, middle, and west China. Out-of-pocket costs decreased by 17.35 times the catastrophic health expenditures to 1.99 times, but the affordability ratio for 14 negotiated medicines was still greater than 1. Conclusions: The NDPN policy improved the availability, utilization, and affordability of anticancer medicines. China's experience in NDPN provides a reference for other countries. However, the availability and affordability of anticancer medicines still need further improvement.

The Effects of Childhood Circumstances on Health in Middle and Later Life: Evidence From China.

Background: This study examined the relationship between childhood circumstances and health in middle and later life. We quantified how childhood circumstances contribute to health in later life, both directly and indirectly, through their effects on potential mediators. Methods: This study used three waves of data from the national longitudinal survey of the China Health and Retirement Longitudinal Study (CHARLS). The final model in this study included 7,476 eligible respondents aged 45 years and above. We constructed a simple health status measure based on the first principal component of CHARLS survey responses with 25 health-related information. It is a multi-dimensional measurement that comprehensively reflects the individual's healthy aging. We formulated childhood circumstances factors into five domains: childhood health and nutrition, childhood socioeconomic status, access to health care, parental genetics, and adverse childhood experiences. Ordered logit regression was conducted to analyze the relationship between health in middle and later life and childhood circumstances, with other explanatory variables controlled. Results: Controlling for educational attainment, personal income, and health status in the last wave, adults who experience good childhood health (poor as the base, coefficient 0.448, p < 0.01), and better family financial status (worse as the base, coefficient 0.173, p < 0.01) have significantly better health during their middle and later life, in comparison, being inconvenient to visit a doctor (coefficient -0.178, p < 0.01), and having two or three adverse childhood experiences (0 as the base, coefficient -0.148, p < 0.01) are significantly associated with poorer health. Childhood circumstances appear to act both through a lasting effect of initial health and financial status in childhood and through their impact on achievements in adulthood. Conclusion: Our findings suggest that investments in health during childhood not only contribute to health in later life but also dynamically improve an individual's educational attainment and personal income, as well as other life prospects. All these returns may extend far beyond childhood and continue throughout the lifespan.