Rubisco accumulation factor 1 (Raf1) plays essential roles in mediating Rubisco assembly and carboxysome biogenesis

Carboxysomes are membrane-free organelles for carbon assimilation in cyanobacteria. The carboxysome consists of a proteinaceous shell that structurally resembles virus capsids and internal enzymes including ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco), the primary carbon-fixing enzyme in photosynthesis. The formation of carboxysomes requires hierarchical self-assembly of thousands of protein subunits, initiated from Rubisco assembly and packaging to shell encapsulation. Here we study the role of Rubisco assembly factor 1 (Raf1) in Rubisco assembly and carboxysome formation in a model cyanobacterium, Synechococcus elongatus PCC7942 (Syn7942). Cryo-electron microscopy reveals that Raf1 facilitates Rubisco assembly by mediating RbcL dimer formation and dimer–dimer interactions. Syn7942 cells lacking Raf1 are unable to form canonical intact carboxysomes but generate a large number of intermediate assemblies comprising Rubisco, CcaA, CcmM, and CcmN without shell encapsulation and a low abundance of carboxysome-like structures with reduced dimensions and irregular shell shapes and internal organization. As a consequence, the Raf1-depleted cells exhibit reduced Rubisco content, CO2-fixing activity, and cell growth. Our results provide mechanistic insight into the chaperone-assisted Rubisco assembly and biogenesis of carboxysomes. Advanced understanding of the biogenesis and stepwise formation process of the biogeochemically important organelle may inform strategies for heterologous engineering of functional CO2-fixing modules to improve photosynthesis

Testing the ALP-photon coupling with polarization measurements of Sagittarius A*

Ultra-light bosons such as axions or axion-like particles (ALPs), are promising candidates to solve the dark matter problem. A unique way to detect such ALPs is to search for the periodic oscillation feature of the position angles of linearly polarized photons emitted from the regions where ALP dark matter forms a solitonic core. In this work, we use the high-resolution polarimetric measurements of the radiation near the super-massive black hole (SMBH) in the center of the Milky Way, i.e., Sagittarius A$^\star$ (Sgr A$^\star$), by a sub-array of the Event Horizon Telescope to search for the ultra-light ALPs. We derive upper limits on the ALP-photon coupling of $\sim 10^{-12}{\rm GeV^{-1}}$ for ALP masses of $m\sim (10^{-19}-10^{-18})$eV. Our results are stronger than that derived from the observations of SN1987A and a population of supernovae in the mass window of ($10^{-19}-10^{-17}$)eV. Improved polarimetric measurements with the full Event Horizon Telescope can further strengthen the constraints.Comment: Accepted for publication in JCAP. 13 pages, 2 figure

Analysis of the behavior and influencing factors of pickled and smoked products consumption in residents in Southwest China

ObjectiveTo investigate the current situation and risk factors of high-frequency consumption of pickled and smoked products in Southwest China and put forward corresponding countermeasures and suggestions.MethodsA questionnaire survey was conducted from February to May in 2021 in Southwest China （Yunnan， Guizhou， Sichuan and Chongqing） by convenient sampling to obtain data. The geographical， demographic and sociological factors， health knowledge and behavior factors were collected. The risk factors of high-frequency pickled and smoked products consumption were analyzed by disordered multi classification logistic regression.ResultsGeographical factor analysis showed that the risk of high-frequency consumption of pickled and smoked products in Yunnan， Guizhou and rural areas was high. The risk of high-frequency consumption of pickled and smoked products in Yunnan province were 2.764 times and 2.126 times higher than that in Chongqing respectively. Among the demographic sociological factors， high-frequency consumption of pickled and smoked products was positively correlated with age and education to a certain extent， and intellectual labor was a protective factor. The most noteworthy factor was the age： the risk of the elderly over 60 years old was the highest， and only 46.70% of the youth aged from 18 had the behavior. In terms of health knowledge and behavior， there was a statistical difference between the knowledge of salt and the consumption of smoked products. The risk of the group with zero correct rate was 1.372 times higher than that of the group with all correct answers. The frequency of drinking alcohol and the risk of pickled and smoked products were basically positively correlated. In the two groups of dependent variables， people who drunk more than three times a week had the highest risk， and the risk of those who never drunk was only 32.10% compared to the drinkers.ConclusionPickled and smoked products are the characteristic food in Southwest China. Geographical factors， demographic and sociological factors， health knowledge and behavior factors are related to high-frequency consumption of pickled and smoked products. It is necessary to control the health risks brought by high-frequency eating behaviors， promote targeted health education in Yunnan， Guizhou and rural areas， and elderly and less educated groups， encourage healthy eating behaviors， and promote the “Healthy Southwest Action” of “Healthy China”

Association between modes of delivery and postpartum dietary patterns: A cross-sectional study in Northwest China

Objective: Puerperae’ dietary patterns (DPs) during the puerperium may be influenced by the mode of delivery, but population studies on this topic are scarce. This study aims to explore the relationship between DPs and different modes of delivery among puerperae. Methods: A cross-sectional study was conducted on 3,345 parturients in Lanzhou, China. The postpartum food intake was measured by a food frequency questionnaire (FFQ). Factor analysis was used to determine the DPs. Multiple linear regression was employed to examine the association between the mode of delivery and DP. Results: In this study, two DPs, i.e., traditional and modern DPs, were identified. Traditional DP was characterized by high energy-adjusted intake of tubers, coarse cereals, rice, whole grains, fishery products, and eggs. Modern DP included a high intake of coffee, non-sugary drinks, wine, tea, and fishery products. Compared with participants with vaginal delivery (reference category), cesarean section had an inverse association with modern DP (β: −0.11, 95% CI: −0.36, −0.09). A significant interaction was found between education level, monthly household income, alcohol drinking, and modes of delivery. The inverse association between cesarean section and modern DP or the intake of coffee was significant among puerperae with higher or lower monthly household income. However, the inverse association between cesarean section and traditional DP was only found among puerperae with higher monthly household income. Moreover, among the participants with high education, cesarean section was positively associated with intake of vegetables. Conclusion: Cesarean puerperae with higher levels of education and those with lower and higher monthly household income had less unhealthy foods intake than those who had vaginal delivery. They need to be accounted for in educational programs and interventions focused on healthy diet recommendations in puerperium.This project was funded by the Chongqing Social Science Planning Project (2017YBSH057) and joint project of the Ministry of Technology and Ministry of Health (2021MSXM215) and Discipline Cultivation Fund of the First Affiliated Hospital of Chongqing Medical University. The funders had no role in the design, analysis, data interpretation and publication of findings

Effect of external beam radiation therapy versus transcatheter arterial chemoembolization for non-diffuse hepatocellular carcinoma (≥ 5 cm): a multicenter experience over a ten-year period

BackgroundThe optimal local treatment for HCC with tumor diameter ≥ 5 cm is not well established. This research evaluated the effectiveness of external beam radiation therapy (EBRT) versus transcatheter arterial chemoembolization (TACE) for HCC with tumor diameter ≥ 5 cm.MethodsA total of 1210 HCC patients were enrolled in this study, including 302 and 908 patients that received EBRT and TACE, respectively. Propensity score matching (PSM) was used to identify patient pairs with similar baseline characteristics. Overall survival (OS) was the primary study endpoint.ResultsWe identified 428 patients using 1:1 PSM for survival comparison. Compared with the TACE group, the EBRT group had a significantly longer median OS (mOS) before (14.9 vs. 12.3 months, p = 0.0085) and after (16.8 vs. 11.4 months, p = 0.0026) matching. In the subgroup analysis, compared with the TACE group, the EBRT group had a significantly longer mOS for HCC with tumor diameters of 5-7 cm (34.1 vs. 14.3 months, p = 0.04) and 7-10 cm (34.4 vs. 10 months, p = 0.00065), whereas for HCC with tumor diameters ≥ 10 cm, no significant difference in mOS was observed (11.2 vs. 11.2 months, p = 0.83). In addition, the multivariable Cox analysis showed that Child-A, alkaline phosphatase < 125 U/L, and EBRT were independent prognostic indicators for longer survival.ConclusionEBRT is more effective than TACE as the primary local treatment for HCC with tumor diameter ≥ 5 cm, especially for HCC with tumor diameter of 5-10 cm

Towards an Evaluation System of Disabled Individuals’ Friendly Communities from the Perspective of Inclusive Development—A Case Study in Jinan

The quality of travel for residents has improved in China’s urban renewal development, but there are still barriers to the activities of disadvantaged groups like people with disabilities in the city, including challenges with accessible travel and a lack of accessible design. All urban people should have access to services and be guaranteed equal rights, according to the inclusive development theory. This study examines the travel requirements and behavioural patterns of the barrier-free groups to safeguard the right of underprivileged groups to participate equally in the urban space. It also determines the impact of various types of urban land use and service facilities on the distribution of barrier-free facilities. An evaluation system based on the needs of the disabled group is established to evaluate the degree of barrier-free facilities in the surveyed areas, summarise the problems shown by the evaluation scores, and propose improvement strategies for the shortcomings of accessibility to residential areas and the controversy through web data crawling and a geographically weighted analysis. From the standpoint of inclusive development, the goal is to lessen the travel issues faced by underprivileged groups and to improve their capacity to take advantage of opportunities and have access to resources

Overview of 1,5-Selective Click Reaction of Azides with Alkynes or Their Synthetic Equivalents

Nowadays, the click reaction of azides with alkynes has evolved rapidly and become one of the most efficient methods to synthesize 1,2,3-triazoles, which are an important class of N-containing heterocycles. While the 1,4-selective click reaction of azides with alkynes is well established to synthesize 1,4-substituted 1,2,3-triazoles, the corresponding 1,5-selective click reaction for the generation of 1,5-substituted-1,2,3-triazoles is much less explored, and there is no systematic review for the 1,5-selective click reaction. This timely review summarizes the discovery and development of 1,5-selective click reactions of azides with alkynes for the synthesis of 1,5-substituted 1,2,3-triazoles. The 1,5-selective click reactions will be divided into three types according to the critical reactive intermediates: metallacyclic intermediates, acetylide intermediate, and formal 1,5-selective azide-alkyne cycloaddition. The related mechanistic studies will also be involved in this review