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Abstract Super large-sized cities and very large-sized cities (“mega-cities” for short) have become the backbone of China's socio-economic development, but they also face outstanding challenges of "urban diseases" due to their high concentration. In comparison to their foreign counterparts, China's mega-cities possess unique characteristics such as rapid growth, high population density, and large numbers of residents. They naturally have the attributes of metropolitan areas due to an administrative management system of an urban system within city territory. Promoting coordinated spatial governance of mega-cities via spatial organization of metropolitan areas not only helps mega-cities better allocate resources at a larger scope and helps expedite the transformation of development patterns, but is also crucial for better implementing new-type urbanization strategies. In response to the issues in China’s previous research and practices related to mega-cities and metropolitan areas, leveraging the “Critical Technology for Spatial Optimization of Metropolitan Areas of City Clusters” of the national key R&D plan in the “14th Five-year Plan” period, we have employed a scientific approach that combines data and models to propose spatial governance strategies. These strategies encompass both the overall metropolitan area level and the cross-border regional level. Our primary focus lies in optimizing the spatial layout of the “three domains” – ecological space, production space, and living space, facilitating functional dispersal, enhancing spatial patterns, adjusting land use structures and spatial resource allocation, coordinating rail transit and the organization of functions along transit lines, and innovating service management for improvement of administrative efficiency. Through the implementation of these diverse measures, we aim to establish a comprehensive composite collaborative system.

Glass fiber reinforced polymer (GFRP) has been considered as an advanced material to replace conventional steel reinforcements in concrete structures to address the corrosion issue. The degradation of GFRP rebars, which may threaten both the durability and safety of infrastructures, is a major concern. To predict the 100-year strength retention of GFRP under various temperature and relative humidity conditions, the environmental reduction factor (CE) is applied in engineering. The conventional CE based on the assumption of logarithmic degradation model is commonly utilized during the degradation phase spanning from a few years to decades; however, it is not applicable to the initial and perpetual degradation phases. To address this issue, a novel environmental reduction factor (CE′) based on the exponential degradation model considering temperature and relative humidity is proposed in this study. Both CE and CE′ are mathematically deduced from empirical degradation data and then evaluated in a case study involving GFRP-concrete samples soaked in water at 23, 40 or 60 °C for up to 12 months within the authors’ dataset. Experimental results show that the GFRP tensile strength degradation is closer to the exponential model, reaching a plateau (47.4%) after 12-month exposure to 60 °C water. Moreover, the tensile strength retention of GFRP rebars in Vancouver (10 °C), Shanghai (16 °C) and Houston (22 °C) is predicted considering various scenarios of relative humidities (0–90%). Further research indicates that CE′ (0.65–0.78) exhibits a smaller value compared to CE (0.81) at a temperature of 22 °C and a relative humidity of 90% following a 100-year exposure period, thereby providing engineers with a more conservative design approach for GFRP in real-world scenarios. Nevertheless, this exponential degradation model requires a thorough consideration of severe degradation state during the extended aging period, which may not be applicable to GFRP structures exhibiting exceptional durability.

In the context of the Chinese government’s advocacy for “Internal Circulation”, ongoing reforms in medical insurance policies raise critical questions about whether the basic medical insurance system can stimulate resident consumption and enhance its quality. Based on five waves of panel data from the China Health and Retirement Longitudinal Survey (CHARLS), this paper analyzes the impact of medical insurance on the consumption scale and structure of middle-aged and older adult rural residents by using the time-varying difference-in-differences (time-varying DID) method. The findings indicate that the Urban–Rural Resident Basic Medical Insurance (URRBMI) effectively stimulates the consumption scale of rural middle-aged and older adult individuals, particularly enhancing non-food consumption, development-oriented spending, and hedonic consumption. This, in turn, optimizes the consumption structure and improves overall consumption quality. Notably, URRBMI significantly enhances the consumption scale and structure among rural middle-aged and older adult women, unmarried individuals, and residents in western China. These results suggest that URRBMI plays a crucial role in alleviating consumption inequality within rural areas and across different regions, providing a theoretical foundation for policy-making.

Abstract Over the past 40 years, China has witnessed the world’s largest urbanization process. In light of its natural and cultural conditions featuring resource scarcity, frequent natural disasters, rich cultural heritage and regional disparities and dynamics, this process aggravates the complex and severe problems faced by urban areas, including resource and environmental damage, security risks and cultural degradation. To address these issues, a shift in national and regional urban spatial layouts from improving economic competitiveness to balancing protection and development as well as security and development is needed. Related theories and research methods should also be adjusted accordingly. Therefore, given China’s specific conditions and regional spatial layouts, the paper introduces the “national spatial planning theory,” which aims to create a sound living environment. The core concept is “precise adaptation,” which ensures the adaption of urban development to natural and cultural conditions. It is the first theory that proposes to develop the national urban spatial layout based on the analysis of ecological environment. It also suggests shifting the focus from eco-environment to security and culture as urbanization progresses and problems change constantly. In addition, a method framework and technical system of “precise analysis, adaptive distribution and dynamic evaluation” is formulated to build an adaptive urban spatial layout on the basis of quantitative analysis of the capacity of spatial resources. The practices of regional planning processes on varying scales in the past 20 years are to illustrate the specific applications of the theoretical approach.

Abstract Colorful circularly polarized luminescence materials are desired for 3D displays, information security and asymmetric synthesis, in which single-emitted materials are ideal owing to self-absorption avoidance, evenly entire-visible-spectrum-covered photon emission and facile device fabrication. However, restricted by the synthesis of chiral broad-luminescent emitters, the realization and application of high-performing single-emitted full-color circularly polarized luminescence is in its infancy. Here, we disclose a single-emitted full-color circularly polarized luminescence system (spiral full-color emission generator), composed of whole-vis-spectrum emissive quantum dots and chiral liquid crystals. The system achieves a maximum luminescence dissymmetry factor of 0.8 and remains an order of 10−1 in visible region by tuning its photonic bandgap. We then expand it to a series of desired customized-color circularly polarized luminescence, build chiral devices and further demonstrate the working scenario in the photoinduced enantioselective polymerization. This work contributes to the design and synthesis of efficient chiroptical materials, device fabrication and photoinduced asymmetric synthesis.

Porcine parvoviruses one through eight (PPV1-PPV8) are prevalent in Chinese swine herds. However, the infection status of all these PPVs in slaughtered pigs is still unclarified. In this study, we detected PPV1-PPV8 in 353 tissue samples collected from slaughtered pigs from six regions of China in 2023. At least one species of PPV was detected in 79.32% of the samples (280 out of 353). Six PPV species were detected, except for PPV4 and PPV8, in slaughtered pigs, within which PPV3 (49.86%), PPV2 (42.49%), and PPV7 (42.21%) were predominant, followed by PPV1 (13.31%), PPV6 (13.31%), and PPV5 (8.22%). Noticeably, co-infection was frequently detected, with 67.50% of PPV-positive samples (189 out of 280) co-infecting with two to six PPVs. In addition, one representative genome for each detected PPV was determined. Multiple sequence alignment determined a large number of substitutions in capsid proteins of PPVs. Genome-based phylogenetic analysis confirmed the PCR detection results. Recombination detection identified two potential recombinants (PPV2 GDCZ2023-2088 strain and PPV3 HLJSYS2023-1654 strain) in slaughtered pigs. Overall, this study provides new insights into the prevalence and evolution of PPVs, particularly in slaughtered pigs in China.

This study investigated the effect of molasses addition on the fermentation quality, chemical composition, and bacterial community of seed pumpkin peel residue (SPPR) mixed with sunflower straw (SS) in microstorage feed. Molasses additions on a dry matter basis (DM) were divided into three groups: 0% control (CON), 1% (MA), and 2% (MB), and the raw materials underwent mixed microstorage for a period of 60 days. MA exhibited the highest content of dry matter (DM), the lowest content of neutral detergent fiber (NDF), acid detergent fiber (ADF), and ammoniacal nitrogen (NH3-N), as well as the lowest microbial diversity abundance and the highest relative abundance of lactobacilli (p < 0.05). MB demonstrated the highest crude protein (CP) content and acetic acid (AA) and propionic acid (PA) concentrations, with the lowest pH. In conclusion, the addition of molasses could enhance the quality of mixed microsilage feeds composed of seeded pumpkin peel pomace (SPPR) and sunflower straw (SS), with the optimal addition of molasses being 1% on a DM basis.

The Brown-Spotted Pit viper (Protobothrops mucrosquamatus), also known as the Chinese habu, is a widespread and highly venomous snake distributed from Northeastern India to Eastern China. Genomics research can contribute to our understanding of venom components and natural selection in vipers. Here, we collected, sequenced and assembled the genome of a male P. mucrosquamatus individual from China. We generated a highly continuous reference genome, with a length of 1.53 Gb and 41.18% of repeat elements content. Using this genome, we identified 24,799 genes, 97.97% of which could be annotated. We verified the validity of our genome assembly and annotation process by generating a phylogenetic tree based on the nuclear genome single-copy genes of six other reptile species. The results of our research will contribute to future studies on Protobothrops biology and the genetic basis of snake venom.

Background Protein-energy wasting (PEW) is a common complication in patients with peritoneal dialysis (PD). Few investigations involved risk factors identification and predictive model construction related to PEW. We aimed to develop a nomogram to predict PEW risk in patients with peritoneal dialysis. Methods We collected data from end-stage renal disease (ESRD) patients who regularly underwent peritoneal dialysis between January 2011 and November 2022 at two hospitals retrospectively. The outcome of the nomogram was PEW. Multivariate logistic regression screened predictors and established a nomogram. We measured the predictive performance based on discrimination ability, calibration, and clinical utility. Evaluation indicators were receiver operating characteristic (ROC), calibrate curve, and decision curve analysis (DCA). The performance calculation of the internal validation cohort validated the nomogram. Results In this study, 369 enrolled patients were divided into development (n = 210) and validation (n = 159) cohorts according to the proportion of 6:4. The incidence of PEW was 49.86%. Predictors were age, dialysis duration, glucose, C-reactive protein (CRP), creatinine clearance rate (Ccr), serum creatinine (Scr), serum calcium, and triglyceride (TG). These variables showed a good discriminate performance in development and validation cohorts (ROC = 0.769, 95% CI [0.705–0.832], ROC = 0.669, 95% CI [0.585–0.753]). This nomogram was adequately calibrated. The predicted probability was consistent with the observed outcome. Conclusion This nomogram can predict the risk of PEW in patients with PD and provide valuable evidence for PEW prevention and decision-making.

Utilizing the heat energy of exhaust gases is a promising application of thermoelectric generator (TEG), which can convert low grade thermal energy into electricity. The annular thermoelectric generator (ATEG) is thought to be much more feasible for cylindrical heat source compared to the flat-plate thermoelectric generator (FTEG) in reference to the compatibility. Nevertheless, the quantitative comparison is lacking to clarify the prevalent geometry of TEG for cylindrical heat source. In this work, the performances of ATEG and FTEG are compared in detail with varying inlet temperature, velocity and the convective heat transfer coefficient when cylindrical heat source is applied. The turbulent heat source is described by the standard κ-ɛ functions together with the two-equation heat transfer model, while the output power and conversion efficiency of the ATEG and FTEG are calculated by solving the coupled thermo-electric equations. Our results showed that the output powers and the conversion efficiencies of ATEG and FTEG both increase with the increase of the inlet velocity, temperature, and the convective heat transfer coefficient. The conversion efficiency of ATEG is always higher than that of FTEG. The conversion efficiency of ATEG becomes even larger than that of FTEG when inlet temperature and/or convective heat transfer coefficient are relatively larger. In contrast, the output power of ATEG has no obvious difference with that of FTEG. This study addressed the condition when the ATEG has obvious advantage compared to the FTEG with cylindrical heat source applied. Our results suggest the annular TEG is better choice for cylindrical hot source especially when the inlet temperature and/or convective heat transfer coefficient are relatively larger. It could be a helpful guide for choosing suitable geometry of TEGs for energy harvesting in complex condition.

Iron-sulfur proteins play essential roles in a wide variety of cellular processes such as respiration, photosynthesis, nitrogen fixation and magnetoreception. The stability of iron-sulfur clusters varies significantly between anaerobic and aerobic conditions due to their intrinsic sensitivity to oxygen. Iron-sulfur proteins are well suited to various practical applications as molecular redox sensors or molecular “wires” for electron transfer. Various technologies have been developed recently using one particular iron-sulfur protein, MagR, as a magnetic tag. However, the limited protein stability and low magnetic sensitivity of MagR hindered its wide application. Here in this study, the iron-sulfur binding site of pigeon clMagR was rationally re-designed. One such mutation, T57C in pigeon MagR, showed improved iron-sulfur binding efficiency and higher iron content, as well as prolonged thermostability. Thus, clMagRT57C can serve as a prototype for further design of more stable and sensitive magnetic toolbox for magnetogenetics in the future.

Nanomedicine has demonstrated great potential in enhancing cancer immunotherapy. However, nanoparticle (NP)-based immunotherapy still has limitations in inducing effective antitumor responses and inhibiting tumor metastasis. Herein, polyethylenimine (PEI) hybrid thin shell hollow mesoporous silica NPs (THMSNs) were applied as adjuvant-nanocarriers and encapsulated with very small dose of photosensitizer chlorine e6 (Ce6) to realize the synergy of photodynamic therapy (PDT)/immunotherapy. Through PEI etching, the obtained Ce6@THMSNs exhibited enhanced cellular internalization and endosome/lysosome escape, which further improved the PDT efficacy of Ce6@THMSNs in destroying tumor cells. After PDT treatment, the released tumor-associated antigens with the help of THMSNs as adjuvants promoted dendritic cells maturation, which further boosted CD8+ cytotoxic T lymphocytes activation and triggered antitumor immune responses. The in vivo experiments demonstrated the significant potency of Ce6@THMSNs-based PDT in obliterating primary tumors and inducing persistent tumor-specific immune responses, thus preventing distant metastasis. Therefore, we offer a THMSNs-mediated and PDT-triggered nanotherapeutic system with immunogenic property, which can elicit robust antitumor immunity and is promising for future clinical development of immunotherapy.

The extinction risk of the giant panda has been demoted from "endangered" to "vulnerable" on the International Union for Conservation of Nature Red List, but its habitat is more fragmented than ever before, resulting in 33 isolated giant panda populations according to the fourth national survey released by the Chinese government. Further comprehensive investigations of the genetic background and in-depth assessments of the conservation status of wild populations are still necessary and urgently needed. Here, we sequenced the genomes of 612 giant pandas with an average depth of ~26x and generated a high-resolution map of genomic variation with more than 20 million variants covering wild individuals from six mountain ranges and captive representatives in China. We identified distinct genetic clusters within the Minshan population by performing a fine-grained genetic structure. The estimation of inbreeding and genetic load associated with historical population dynamics suggested that future conservation efforts should pay special attention to the Qinling and Liangshan populations. Releasing captive individuals with a genetic background similar to the recipient population appears to be an advantageous genetic rescue strategy for recovering the wild giant panda populations, as this approach introduces fewer deleterious mutations into the wild population than mating with differentiated lineages. These findings emphasize the superiority of large-scale population genomics to provide precise guidelines for future conservation of the giant panda. [ABSTRACT FROM AUTHOR]

Iron-sulfur clusters are essential cofactors for proteins involved in various biological processes, such as electron transport, biosynthetic reactions, DNA repair, and gene expression regulation. Iron-sulfur cluster assembly protein IscA1 (or MagR) is found within the mitochondria of most eukaryotes. Magnetoreceptor (MagR) is a highly conserved A-type iron and iron-sulfur cluster-binding protein, characterized by two distinct types of iron-sulfur clusters, [2Fe-2S] and [3Fe-4S], each conferring unique magnetic properties. MagR forms a rod-like polymer structure in complex with photoreceptive cryptochrome (Cry) and serves as a putative magnetoreceptor for retrieving geomagnetic information in animal navigation. Although the N-terminal sequences of MagR vary among species, their specific function remains unknown. In the present study, we found that the N-terminal sequences of pigeon MagR, previously thought to serve as a mitochondrial targeting signal (MTS), were not cleaved following mitochondrial entry but instead modulated the efficiency with which iron-sulfur clusters and irons are bound. Moreover, the N-terminal region of MagR was required for the formation of a stable MagR/Cry complex. Thus, the N-terminal sequences in pigeon MagR fulfil more important functional roles than just mitochondrial targeting. These results further extend our understanding of the function of MagR and provide new insights into the origin of magnetoreception from an evolutionary perspective. [ABSTRACT FROM AUTHOR]

Birds exhibit extraordinary mobility and remarkable navigational skills, obtaining guidance cues from the Earth’s magnetic field for orientation and long-distance movement. Bird species also show tremendous diversity in navigation strategies, with considerable differences even within the same taxa and among individuals from the same population. The highly conserved iron and iron-sulfur cluster binding magnetoreceptor (MagR) protein is suggested to enable animals, including birds, to detect the geomagnetic field and navigate accordingly. Notably, MagR is also implicated in other functions, such as electron transfer and biogenesis of iron-sulfur clusters, raising the question of whether variability exists in its biochemical and biophysical features among species, particularly birds. In the current study, we conducted a comparative analysis of MagR from two different bird species, including the migratory European robin and the homing pigeon. Sequence alignment revealed an extremely high degree of similarity between the MagRs of these species, with only three sequence variations. Nevertheless, two of these variations underpinned significant differences in metal binding capacity, oligomeric state, and magnetic properties. These findings offer compelling evidence for the marked differences in MagR between the two avian species, potentially explaining how a highly conserved protein can mediate such diverse functions. [ABSTRACT FROM AUTHOR]

The ability to navigate long distances is essential for many animals to locate shelter, food, and breeding grounds. Magnetic sense has evolved in various migratory and homing species to orient them based on the geomagnetic field. A highly conserved ironsulfur cluster assembly protein IscA is proposed as an animal magnetoreceptor (MagR). Iron-sulfur cluster binding is also suggested to play an essential role in MagR magnetism and is thus critical in animal magnetoreception. In the current study, we provide evidence for distinct iron binding and iron-sulfur cluster binding in MagR in pigeons, an avian species that relies on the geomagnetic field for navigation and homing. Pigeon MagR showed significantly higher total iron content from both iron- and ironsulfur binding. Y65 in pigeon MagR was shown to directly mediate mononuclear iron binding, and its mutation abolished iron-binding capacity of theprotein. Surprisingly, both iron binding and iron-sulfur binding demonstrated synergistic effects, and thus appear to be integral and indispensable to pigeon MagR magnetism. These results not only extend our current understanding of the origin and complexity of MagR magnetism, but also imply a possible molecular explanation for the huge diversity in animal magnetoreception. [ABSTRACT FROM AUTHOR]