A site-resolved two-dimensional quantum simulator with hundreds of trapped ions.

A large qubit capacity and an individual readout capability are two crucial requirements for large-scale quantum computing and simulation1. As one of the leading physical platforms for quantum information processing, the ion trap has achieved a quantum simulation of tens of ions with site-resolved readout in a one-dimensional Paul trap2-4 and of hundreds of ions with global observables in a two-dimensional (2D) Penning trap5,6. However, integrating these two features into a single system is still very challenging. Here we report the stable trapping of 512 ions in a 2D Wigner crystal and the sideband cooling of their transverse motion. We demonstrate the quantum simulation of long-range quantum Ising models with tunable coupling strengths and patterns, with or without frustration, using 300 ions. Enabled by the site resolution in the single-shot measurement, we observe rich spatial correlation patterns in the quasi-adiabatically prepared ground states, which allows us to verify quantum simulation results by comparing the measured two-spin correlations with the calculated collective phonon modes and with classical simulated annealing. We further probe the quench dynamics of the Ising model in a transverse field to demonstrate quantum sampling tasks. Our work paves the way for simulating classically intractable quantum dynamics and for running noisy intermediate-scale quantum algorithms7,8 using 2D ion trap quantum simulators.

Emergence of multi-body interactions in a fermionic lattice clock.

Alkaline-earth atoms have metastable 'clock' states with minute-long optical lifetimes, high-spin nuclei and SU(N)-symmetric interactions, making them powerful platforms for atomic clocks1, quantum information processing2 and quantum simulation3. Few-particle systems of such atoms provide opportunities to observe the emergence of complex many-body phenomena with increasing system size4. Multi-body interactions among particles are emergent phenomena, which cannot be broken down into sums over underlying pairwise interactions. They could potentially be used to create exotic states of quantum matter5,6, but have yet to be explored in ultracold fermions. Here we create arrays of isolated few-body systems in an optical clock based on a three-dimensional lattice of fermionic 87Sr atoms. We use high-resolution clock spectroscopy to directly observe the onset of elastic and inelastic multi-body interactions among atoms. We measure the frequency shifts of the clock transition for varying numbers of atoms per lattice site, from n = 1 to n = 5, and observe nonlinear interaction shifts characteristic of elastic multi-body effects. These measurements, combined with theory, elucidate an emergence of SU(N)-symmetric multi-body interactions, which are unique to fermionic alkaline-earth atoms. To study inelastic multi-body effects, we use these frequency shifts to isolate n-occupied sites in the lattice and measure the corresponding lifetimes of the clock states. This allows us to access the short-range few-body physics without experiencing the systematic effects that are encountered in a bulk gas. The lifetimes that we measure in the isolated few-body systems agree very well with numerical predictions based on a simple model for the interatomic potential, suggesting a universality in ultracold collisions. By connecting these few-body systems through tunnelling, the favourable energy and timescales of the interactions will allow our system to be used for studies of high-spin quantum magnetism7,8 and the Kondo effect3,9.

Prognostic value of serial coronary computed tomography angiography-derived perivascular fat-attenuation index and plaque volume in patients with suspected coronary artery disease.

AIMS: To investigate the prognostic value of serial coronary computed tomography angiography (CCTA) derived plaque information, fractional flow reserve (CT-FFR), and perivascular fat-attenuation index (FAI) on major adverse cardiac events (MACE) in patients with suspected coronary artery disease. MATERIALS AND METHODS: A total of 252 patients who underwent serial CCTA between January 2018 and December 2021 and were followed until June 2022. MACE were recorded. The analysis indexes included percent diameter stenosis (%DS), lesion length, plaque volume, CT-FFR, and FAI, with an emphasis on their changes between the baseline and follow-up CCTAs. Multivariate regression analysis were employed to identify independent risk factors for MACE. RESULTS: After a median follow-up of 48-month, MACE occurred in 32 patients (12.7%). Patients with MACE displayed more severe stenosis, longer lesions, and larger plaque volumes in both baseline and follow-up CCTAs compared with no-MACE patients (all P<0.05). Patients with MACE displayed more severe stenosis, longer lesion, and larger plaque volume in both baseline and follow-up CCTAs compared with no-MACE patients. In addition, MACE patients also showed lower CT-FFR and higher △CT-FFR. Although FAI was significantly higher in MACE patients at baseline CCTA, FAI was notably increased in MACE patients, and decreased in the no-MACE patients (all P<0.05). Logistic regression analysis showed that ΔFAI, %DS, and plaque volume were independent predictors of MACE, with ΔFAI being the most significant (OR: 16.725, P<0.000). A multivariable model showed a significantly improved C-index of 0.903 (95% confidence interval: 0.836-0.970) for MACE prediction, when compared with single index alone. CONCLUSIONS: Serial CCTA-derived ΔFAI, %DS, and plaque volume are crucial independent predictors of MACE in patients with suspected coronary artery disease, highlighting the importance of CCTA in patient risk stratification and prognostic assessment.

Higher baseline subcortical net water uptake in computed tomography predicts malignant middle cerebral artery infarction in patients with acute ischemic stroke.

AIM: The objective of this study was to assess the predictive performance of net water uptake (NWU) based on the Alberta stroke program early CT score (ASPECTS) from different ASPECT regions in relation to the development of malignant middle cerebral artery (MCA) infarction. MATERIAL AND METHODS: Patients with acute ischemic stroke (AIS) of the MCA territory were retrospectively enrolled between January 2019 and July 2022. Patients were divided into two groups according to the follow-up CT after 24-48 hours: malignant and nonmalignant infarction. NWUs were measured on diverse ASPECT regions on admission non-contrast CT, namely affected ASPECTS-NWU (af-ASPECTS-NWU), subcortical ASPECTS-NWU (sc-ASPECTS-NWU), and cortical ASPECTS-NWU (c-ASPECTS-NWU). Baseline characteristics were collected for univariate analyses and multivariate regression analyses to explore the independent risk factors for malignant infarction. Receiver operating characteristic (ROC) curves were plotted and compared. RESULTS: patients were included in the final analysis. Malignant MCA infarction was achieved in 42 (27.45%) patients and nonmalignant was 111 (72.55%). Compared with the nonmalignant infarction group, higher baseline National Institute of Health stroke scale (NIHSS) score, af-ASPECTS-NWU, c-ASPECTS-NWU, sc-ASPECTS-NWU, and lower ASPECTS were noted in the malignant infarction group (all P < 0.001). Multivariate logistic regression showed that only baseline sc-ASPECTS-NWU (>3.6%) was a positive factor for malignant MCA infarction. The ROC analysis indicated the highest predictive value of sc-ASPECTS-NWU for indicating malignant infarction with the area under ROC curve (AUC) 0.91. CONCLUSION: Higher baseline sc-ASPECTS-NWU was a quantitative predictor for malignant MCA infarction in patients with AIS, which could be helpful for treatment decisions.

[Bioinformatics-based analysis of the effect of general Transcription Factor IIH on prognosis of Prostate cancer].

Objective: To investigate the genetic and expression characteristics of transcription factor IIH (TFIIH) in pre-initiationcomplex in prostate cancer (PCa) and its relationship with prostate cancer progression. Methods: Analyzing the expression characteristics and clinical signification of TFIIH subunits about 495 cases of PCa and 52 cases of adjacent cancer in The Cancer Genome Atlas-Prostate adenocarcinoma (TCGA-PRAD) database. PCa microarray chip was used to verify the correlation between the key factor General Transcription Factor IIH Subunit 4 (GTF2H4) in TFIIH and clinical features. Results: The 495 patients with PCa were (61.01±6.82) years old.The mRNA expression of ERCC3、GTF2H4 and MNAT1 were high in PCa tissues with GS≥8(P<0.05). The expression of GTF2H4 and MNAT1 were relevant to the pathological stages(P<0.05). High expression of GTF2H4 has higher biochemical recurrence (BCR) rate in PCa patients(HR=2.47, 95%CI:1.62-3.77, P<0.001), which has better predictive effect of BCR in PCa patients(The 3rd, 5th, and 7th year AUC all>0.7) than other subunits, and it has been verified in four additional databases. Single-factor Cox regression analysis showed that GTF2H4 were risk factors for BCR (HR=2.470, 95%CI:1.620-3.767, P<0.001) and GTF2H5 were protective factors(HR=0.506,95%CI: 0.336-0.762, P=0.001). The results of immunohistochemical staining showed that the protein expression of GTF2H4 was correlated with the clinical features of PCa patients.The differences of the above results were statistically significant. Conclusion: GTF2H4, the key factor of TFIIH, is highly expressed in PCa and indicates a poor prognosis.

[Thoughts and suggestions on digital services to enhance the level of vaccination management].

With the development of information technology and the increasing demand for vaccination services among the people, it is a definite trend to enhance the quality of vaccination services through digitization. This article starts with a clear concept of digital services for vaccination, introduces the current development status in China and abroad, analyzes the advantages and disadvantages of existing models in leading regions, takes a glean from the summation, and proposes targeted solutions. This study suggests establishing a departmental coordination mechanism for data interconnection and sharing, formulating data standards and functional specifications, enhancing the functionalities of the immunization planning information system, strengthening data collection and analytical usage, and intensifying appointment management and science and health education to provide expert guidance for the construction of digital vaccination services across the country in the future.

[Value of histological activity in predicting endoscopic relapse among patients of ulcerative colitis in endoscopic remission].

Objective: To investigate the value of histological evaluation in predicting endoscopic relapse among patients with ulcerative colitis (UC) who were in endoscopic remission, and to compare the usefulness of various histological scoring systems. Methods: Histological sections from 61 patients with UC who were in endoscopic remission were retrospectively analyzed, at Peking University Third Hospital, Beijing, China from January 2015 to June 2021. They were subdivided into endoscopic persistent remission group (remission group, n=31, Mayo endoscopic score 0) and endoscopic relapse group (relapse group, n=30, Mayo endoscopic score≥1) according to the results of the first endoscopic reexamination after the biopsy. Histological evaluation was performed using the Geboes score (GS) and its simplified version (SGS), the Nancy index (NI) and the Robarts histopathological index (RHI). The median and maximum histological scores for each case in all biopsies were recorded. Univariate comparisons were performed using chi-squares and multivariate analysis using binary logistic regression. The values of four histological evaluation systems for predicting endoscopic relapse among UC patients in endoscopic remission were analyzed using receiver operating characteristic (ROC) curves. Results: Significant differences were observed between the remission and relapse groups. The differences were more pronounced in the maximum histological scores; the mean and highest results of area under the ROC curve scores (AUC) for GS, SGS, NI, and RHI were 0.657, 0.668, 0.682, 0.691, and 0.866, 0.863, 0.864, 0.869, respectively. The differences were statistically significant (P<0.05). The corresponding best cut-offs were GS≥2B.1, SGS≥2B.1, NI≥2, and RHI≥2.5, respectively, which meant mild active inflammation histologically, while there was no statistical difference of AUC among the four histological scoring indices (P>0.05). Univariate and multivariate analyses revealed statistically significant differences in the number of neutrophils in the epithelium and lamina propria (P<0.05). Conclusions: Biopsies from UC patients in endoscopic remission may still have histological active inflammation which appears to correlate with endoscopic relapse. Four commonly used histological scoring systems can be used to assess the risk of endoscopic relapse among UC patients in endoscopic remission. The patients who more likely have endoscopic relapse seem to have a histological score greater than the cut-off value (i.e., mild histological activity). The maximum histological scores can accurately predict the risk of endoscopic relapse, while the presence of epithelial and laminar propria neutrophil infiltrates can independently predict the endoscopic relapse in these patients. Considering the utility and convenience in routine practice, NI is recommended for evaluating histological inflammatory activity.

[Quality Control Indexes for Oncology (2023 edition) and hot topics in breast surgery].

The National Health Commission of the People's Republic of China has formulated the Quality Control Indexes for Oncology (2023 edition), with the objective of improving medical quality scientifically, refined and standardized. Among these indexes, the rate of pretreatment clinical TNM staging and the coincidence rate of evaluation of pretreatment TNM staging lay national standards for patients to formulate rational and targeted treatment strategies. This article reviewed the literature and referred to Chinese Medical Association Clinical Practice Guide for Breast Surgery, and presented recommendations for the hot topics of breast surgery, such as pathological sampling of the breast specimen, sentinel lymph node biopsy for early-stage breast cancer, breast conserving surgery, axillary lymph node dissection, breast reconstruction surgery, endoscopic-assisted breast surgery, the principles of surgical treatment for metastatic breast cancer, neoadjuvant treatment for advanced disease, and surgical grade of breast surgery, which have been widely concerned in recent years, to help improve homogenization of breast cancer treatment in China.

[Paying attention to safety of posterior chamber phakic intraocular lens implantation].

Posterior chamber phakic intraocular lens implantation is a type of intraocular surgery. With advancements in implant materials and design, this procedure has seen rapid adoption and widespread use in ophthalmology clinics in recent years. However, the changes in surgical techniques and the occurrence of postoperative complications have raised safety concerns that require significant attention in clinical practice. This paper aims to address the key factors influencing the safety of posterior chamber phakic intraocular lens implantation, exploring relevant characteristics, mechanisms, and current challenges. By emphasizing the importance of this surgery and proposing effective measures, it aims to provide guidance for clinical practice, enhance the safety of posterior chamber phakic intraocular lens implantation, and foster the healthy advancement of this surgical technique.

Spin-orbit-coupled fermions in an optical lattice clock.

Engineered spin-orbit coupling (SOC) in cold-atom systems can enable the study of new synthetic materials and complex condensed matter phenomena. However, spontaneous emission in alkali-atom spin-orbit-coupled systems is hindered by heating, limiting the observation of many-body effects and motivating research into potential alternatives. Here we demonstrate that spin-orbit-coupled fermions can be engineered to occur naturally in a one-dimensional optical lattice clock. In contrast to previous SOC experiments, here the SOC is both generated and probed using a direct ultra-narrow optical clock transition between two electronic orbital states in 87Sr atoms. We use clock spectroscopy to prepare lattice band populations, internal electronic states and quasi-momenta, and to produce spin-orbit-coupled dynamics. The exceptionally long lifetime of the excited clock state (160 seconds) eliminates decoherence and atom loss from spontaneous emission at all relevant experimental timescales, allowing subsequent momentum- and spin-resolved in situ probing of the SOC band structure and eigenstates. We use these capabilities to study Bloch oscillations, spin-momentum locking and Van Hove singularities in the transition density of states. Our results lay the groundwork for using fermionic optical lattice clocks to probe new phases of matter.