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Wuhan was the epicentre of the COVID-19 outbreak in China. We aimed to determine the seroprevalence and kinetics of anti-SARS-CoV-2 antibodies at population level in Wuhan to inform the development of vaccination strategies. In this longitudinal cross-sectional study, we used a multistage, population-stratified, cluster random sampling method to systematically select 100 communities from the 13 districts of Wuhan. Households were systematically selected from each community and all family members were invited to community health-care centres to participate. Eligible individuals were those who had lived in Wuhan for at least 14 days since Dec 1, 2019. All eligible participants who consented to participate completed a standardised electronic questionnaire of demographic and clinical questions and self-reported any symptoms associated with COVID-19 or previous diagnosis of COVID-19. A venous blood sample was taken for immunological testing on April 14–15, 2020. Blood samples were tested for the presence of pan-immunoglobulins, IgM, IgA, and IgG antibodies against SARS-CoV-2 nucleocapsid protein and neutralising antibodies were assessed. We did two successive follow-ups between June 11 and June 13, and between Oct 9 and Dec 5, 2020, at which blood samples were taken. Of 4600 households randomly selected, 3599 families (78·2%) with 9702 individuals attended the baseline visit. 9542 individuals from 3556 families had sufficient samples for analyses. 532 (5·6%) of 9542 participants were positive for pan-immunoglobulins against SARS-CoV-2, with a baseline adjusted seroprevalence of 6·92% (95% CI 6·41–7·43) in the population. 437 (82·1%) of 532 participants who were positive for pan-immunoglobulins were asymptomatic. 69 (13·0%) of 532 individuals were positive for IgM antibodies, 84 (15·8%) were positive for IgA antibodies, 532 (100%) were positive for IgG antibodies, and 212 (39·8%) were positive for neutralising antibodies at baseline. The proportion of individuals who were positive for pan-immunoglobulins who had neutralising antibodies in April remained stable for the two follow-up visits (162 [44·6%] of 363 in June, 2020, and 187 [41·2%] of 454 in October–December, 2020). On the basis of data from 335 individuals who attended all three follow-up visits and who were positive for pan-immunoglobulins, neutralising antibody levels did not significantly decrease over the study period (median 1/5·6 [IQR 1/2·0 to 1/14·0] at baseline vs 1/5·6 [1/4·0 to 1/11·2] at first follow-up [p=1·0] and 1/6·3 [1/2·0 to 1/12·6] at second follow-up [p=0·29]). However, neutralising antibody titres were lower in asymptomatic individuals than in confirmed cases and symptomatic individuals. Although titres of IgG decreased over time, the proportion of individuals who had IgG antibodies did not decrease substantially (from 30 [100%] of 30 at baseline to 26 [89·7%] of 29 at second follow-up among confirmed cases, 65 [100%] of 65 at baseline to 58 [92·1%] of 63 at second follow-up among symptomatic individuals, and 437 [100%] of 437 at baseline to 329 [90·9%] of 362 at second follow-up among asymptomatic individuals). 6·92% of a cross-sectional sample of the population of Wuhan developed antibodies against SARS-CoV-2, with 39·8% of this population seroconverting to have neutralising antibodies. Our durability data on humoral responses indicate that mass vaccination is needed to effect herd protection to prevent the resurgence of the epidemic. Chinese Academy of Medical Sciences & Peking Union Medical College, National Natural Science Foundation, and Chinese Ministry of Science and Technology. For the Chinese translation of the abstract see Supplementary Materials section.

Integrated optics provides a versatile platform for quantum information processing and transceiving with photons 1 – 8 . The implementation of quantum protocols requires the capability to generate multiple high-quality single photons and process photons with multiple high-fidelity operators 9 – 11 . However, previous experimental demonstrations were faced by major challenges in realizing sufficiently high-quality multi-photon sources and multi-qubit operators in a single integrated system 4 – 8 , and fully chip-based implementations of multi-qubit quantum tasks remain a significant challenge 1 – 3 . Here, we report the demonstration of chip-to-chip quantum teleportation and genuine multipartite entanglement, the core functionalities in quantum technologies, on silicon-photonic circuitry. Four single photons with high purity and indistinguishablity are produced in an array of microresonator sources, without requiring any spectral filtering. Up to four qubits are processed in a reprogrammable linear-optic quantum circuit that facilitates Bell projection and fusion operation. The generation, processing, transceiving and measurement of multi-photon multi-qubit states are all achieved in micrometre-scale silicon chips, fabricated by the complementary metal–oxide–semiconductor process. Our work lays the groundwork for large-scale integrated photonic quantum technologies for communications and computations. Four single-photon states are generated and entangled on a single micrometre-scale silicon chip, and provide the basis for the demonstration of chip-to-chip quantum teleportation.

High-quality regional development should be promoted by facilitating inter-regional mobility of heterogeneous labor force to optimize its spatial allocation. This study incorporates skill relatedness into spatial categorization and selection effects, and explores how skill-relatedness affects the location choice of heterogeneous labor force. To do so, we use labor force migration data and employee data by occupation subcategory from the 2000 National Population Census and 2015 National Population Sample Survey. The empirical evidence provides three major findings. First, there are significant regional differences in labor migration rates by the occupational group between cities in China, and the trend is increasing. Regional concentration of location choice is increasing and six significant agglomerations are formed. Second, skill relatedness positively affects the location choice of the heterogeneous labor force in Chinese cities. When cities’ skill-relatedness is more robust, influence on labor location choice is more remarkable. In cities with high-size classes, the effect of high-skill relatedness on labor location choice is higher. Third, labor force with solid skill relatedness with regional employment moves to the location owing to the spatial sorting effect. Labor force without skill relatedness or weak relatedness moves out or does not move to the location owing to the spatial selection effect.

Acute-on-chronic liver failure (ACLF) is an extremely severe clinical syndrome, often associated with systemic inflammation, coagulation dysfunction, and fibrinolysis abnormalities. Fibrin degradation product (FDP), as a byproduct of fibrinolysis, is a crucial indicator reflecting the state of fibrinolysis. The objective of this study is to investigate the relationship between FDP levels and the 28-day mortality rate in patients with ACLF. We retrospectively enrolled 520 patients with hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) who underwent artificial liver support system therapy and collected relevant clinical data at admission. Cox regression analysis was employed to investigate the relationship between FDP levels and the 28-day mortality rate, and the predictive value of FDP was evaluated using receiver operating characteristic (ROC) curves. Among the 520 eligible patients, the 28-day mortality rate was 20.2%. The FDP levels of surviving patients were significantly lower than those of deceased patients [6.15 (3.23–10.97) vs. 16.98 (9.58–28.93), P  < 0.001]. Through multivariate Cox proportional hazards analysis, after adjusting for confounding factors, It was observed that for every 10 µg/mL increase in FDP levels, the risk increased by 12.8% [HR = 1.128 (95% CI: 1.044–1.219), P  < 0.001]. Compared to patients with low FDP levels (< 11.1 µg/mL), patients with high FDP levels (≥ 11.1 µg/mL) demonstrated a markedly higher mortality risk [HR = 3.222 (95% CI: 1.999–5.192), P  < 0.001]. Among various prognostic scores, the COSSH-ACLF score exhibited the largest area under the receiver operating characteristic curve (AUROC), comparable to that of FDP ( P  = 0.891), and its predictive performance was superior to that of FIB and D-dimer. Additionally, for patients who received three or more sessions of artificial liver support system therapy, those with high FDP levels had a significantly reduced 28-day mortality risk. Elevated FDP levels are associated with the 28-day prognosis in patients with HBV-ACLF. Moreover, undergoing multiple sessions of artificial liver treatment is associated with favorable survival outcomes for patients with high FDP levels (≥ 11.1 µg/mL).

Quantum key distribution provides an efficient means to exchange information in an unconditionally secure way. Historically, quantum key distribution protocols have been based on binary signal formats, such as two polarization states, and the transmitted information efficiency of the quantum key is intrinsically limited to 1 bit/photon. Here we propose and experimentally demonstrate, for the first time, a high-dimensional quantum key distribution protocol based on space division multiplexing in multicore fiber using silicon photonic integrated lightwave circuits. We successfully realized three mutually unbiased bases in a four-dimensional Hilbert space, and achieved low and stable quantum bit error rate well below both the coherent attack and individual attack limits. Compared to previous demonstrations, the use of a multicore fiber in our protocol provides a much more efficient way to create high-dimensional quantum states, and enables breaking the information efficiency limit of traditional quantum key distribution protocols. In addition, the silicon photonic circuits used in our work integrate variable optical attenuators, highly efficient multicore fiber couplers, and Mach-Zehnder interferometers, enabling manipulating high-dimensional quantum states in a compact and stable manner. Our demonstration paves the way to utilize state-of-the-art multicore fibers for noise tolerance high-dimensional quantum key distribution, and boost silicon photonics for high information efficiency quantum communications. Silicon chip-to-chip high-dimensional quantum key distribution Quantum key distribution (QKD) enables ultimate secure communication guaranteed by quantum mechanics. Most of QKD systems are based on binary encoding utilizing bulky, discrete, and expensive devices. Consequently, a large scale deployment of this technology has not been achieved. A solution may be by photonic integration, which provides excellent performances and are particularly suitable for manipulation of quantum states. The Center for Silicon Photonics for Optical Communication (SPOC) led by Prof. Leif Katsuo Oxenløwe at the Technical University of Denmark demonstrated an integrated solution for manipulation of new high-dimensional quantum states using spatial degrees of freedom (the cores of a multicore fiber). We achieved the first silicon chip-to-chip decoy-state high-dimensional QKD, which is suitable for longer transmission distance with higher secret key rate, better resilience to noise, and higher information efficiency.

The random walk formalism is used across a wide range of applications, from modelling share prices to predicting population genetics. Likewise, quantum walks have shown much potential as a framework for developing new quantum algorithms. Here we present explicit efficient quantum circuits for implementing continuous-time quantum walks on the circulant class of graphs. These circuits allow us to sample from the output probability distributions of quantum walks on circulant graphs efficiently. We also show that solving the same sampling problem for arbitrary circulant quantum circuits is intractable for a classical computer, assuming conjectures from computational complexity theory. This is a new link between continuous-time quantum walks and computational complexity theory and it indicates a family of tasks that could ultimately demonstrate quantum supremacy over classical computers. As a proof of principle, we experimentally implement the proposed quantum circuit on an example circulant graph using a two-qubit photonics quantum processor. Quantum walks are a potential framework for developing quantum algorithms, but have so far been limited to analogue quantum-simulation approaches that do not scale. Here, the authors provide a protocol for simulating exponentially large quantum walks using a polynomial number of quantum gates and qubits.

As the indication for immunotherapy is rapidly expanding, it is crucial to accurately identify patients who are likely to respond. Infiltration of B cells into many tumor types correlates with a good response to immune checkpoint inhibitor (ICI) therapy. However, B cells' roles in the anti-tumor response are far from clear. Based on single-cell transcriptomic data for ICI-treated patients, we identified a B-cell cluster [B (ICI-Responsive B) cells] and described the phenotype, cell-cell communication, biological processes, gene signature, and prognosis value of B cells through bioinformatic analysis, tissue immunofluorescence, and animal experiments. Surgery samples from 12 non-small cell lung carcinoma (NSCLC) patients with adjuvant checkpoint blockade were evaluated as external validation. B cells were identified as a subset of CD20 CD22 ADAM28 B cells with a memory phenotype. Bioinformatic analysis revealed that B cells had enhanced cell viability and epigenetic regulation, and that ALOX5AP, MIF, and PTPRC/CD45 expressed by myeloid cells may be critical coordinators of diverse biological processes of B cells. Immunofluorescence confirmed the presence of B cells in tertiary lymphoid structures (TLSs) in skin SCC, RCC, CRC, and breast cancer. B -associated gene signatures correlate with positive outcomes in patients with melanoma, glioblastoma, NSCLC, HNSCC, or RCC treated with ICI therapy, and B -cell density predicted NSCLC patients' response to checkpoint immunotherapy. In line with this, melanoma-bearing mice depleted of B cells were resistant to ICIs. CD20 CD22 ADAM28 B cells were present in cancer-associated TLS and promoted the response to ICI therapy.

Pancreatic cancer is a deadly disease with little response to standard therapies. Irreversible electroporation (IRE) has emerged as a novel ablative technique for the clinical treatment of pancreatic cancer. Combinations of IRE and immunotherapies, including anti‐programmed death 1 (αPD1) immune checkpoint blockade, have shown promising efficacy in both preclinical and clinical studies. However, tumor recurrence remains an obstacle that needs to be overcome. It herein is shown that IRE induces a substantial infiltration of neutrophils into pancreatic tumors. These neutrophils are then polarized into a protumor phenotype by immunosuppressive cues, in particular transforming growth factor β (TGF‐β). Using glutathione‐responsive degradable mesoporous silica nanoparticles loaded with SB525334, an inhibitor of TGF‐β1 receptor, it is demonstrated that local inhibition of TGF‐β within the tumor microenvironment promotes neutrophil polarization into an antitumor phenotype, enhances pancreatic cancer response to combined IRE and αPD1 therapy, and induces long‐term antitumor memory. The therapeutic efficacy is also attributed to tumor infiltration by CD8+ cytotoxic T cells, depletion of regulatory T cells, and maturation of antigen‐presenting dendritic cells. Thus, modulating neutrophil polarization with nanomedicine is a promising strategy for treating pancreatic cancer. Treatment of pancreatic tumor by irreversible electroporation (IRE) induces a rapid infiltration by neutrophils, which polarize into a protumor phenotype and negatively correlate with therapeutic outcome. Local release of transforming growth factor‐β inhibitor within the tumor microenvironment promotes neutrophils polarization toward an antitumor phenotype and enhances tumor response to combined IRE and immunotherapy.

Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal cancer, marked by high molecular heterogeneity and limited responsiveness to targeted or immune therapies. Ribosome biogenesis (Ribosis), a central regulator of cell growth and metabolism, has emerged as a driver of tumor aggressiveness. However, its role in ccRCC pathogenesis and prognosis remains poorly defined. We integrated bulk RNA sequencing, single-cell RNA sequencing, and spatial transcriptomics sequencing data to dissect the biological functions and clinical relevance of Ribosis-related genes in ccRCC. Through pseudotime trajectory analysis and metabolic flux inference, we examined malignant progression and metabolic reprogramming. A prognostic model based on a Ribosis-related signature (RBRS) was built using 118 machine learning algorithm combinations and validated in internal and external cohorts. A web-based calculator was also developed. We further analyzed immune infiltration, genomic alterations, tumor microenvironment features, and drug sensitivity. Expression of five core Ribosis-related genes (RPL38, RPS2, RPS14, RPS19, RPS28) was validated by qRT-PCR. We identified a Ribosis-high malignant subpopulation with enhanced stemness, poor prognosis, and elevated oxidative phosphorylation. These cells showed increased metabolic activity, especially in the pyruvate-lactate axis, potentially facilitating immune evasion. The RBRS model outperformed 32 published signatures (C-index = 0.68). High-risk patients exhibited an \"immune-activated yet immunosuppressed\" microenvironment, with increased CD8 T-cell infiltration and elevated regulatory T cells, myeloid-derived suppressor cells, and immune checkpoint expression (e.g., PDCD1, CTLA-4). Despite active antigen presentation and immune cell recruitment, terminal tumor-killing capacity was impaired. High-risk tumors also showed higher mutation burden, frequent copy number loss of tumor suppressor genes, and resistance to common targeted therapies. The five RBRS genes were significantly upregulated in tumor tissues, consistent with bulk RNA-seq data. We reveal Ribosis as a key driver of ccRCC progression. The RBRS model demonstrates robust prognostic value and translational utility, linking Ribosis to metabolism, immune dysfunction, and therapy resistance, offering new insights for risk stratification and precision treatment in ccRCC.

Braiding is one of the oldest crafting techniques in human history, yet today it plays a key role across a wide range of scientific disciplines, from biology to physics. However, how fractal geometry interplays with non-Hermitian band braiding remains unexplored. Here, we bridge fractal physics and non-Hermitian topology by introducing topological fractal braiding, which can produce self-similar topological winding matrices. Furthermore, through tight-binding lattice model construction, we prove these fractal winding matrices govern non-Hermitian skin modes, yielding a scale-invariant skin effect where the ratio of left- to right-localized skin modes remains conserved through fractal iterations. We design and fabricate reconfigurable non-Hermitian topoelectrical circuits to experimentally reconstruct the fractal braiding of non-Hermitian bands, confirming our theory. Our work resolves how fractal geometry manifests in non-Hermitian band braiding and impacts skin effects, demonstrating scalable control of complex spectral topologies. While non-Hermitian physics and fractal geometry have been widely studied, their interplay in band braiding remains largely unexplored. The authors establish topological fractal braiding in non-Hermitian systems with scale-invariant skin effects, experimentally demonstrated using reconfigurable circuits.