Formation of robust bound states of interacting microwave photons

Systems of correlated particles appear in many fields of modern science and represent some of the most intractable computational problems in nature. The computational challenge in these systems arises when interactions become comparable to other energy scales, which makes the state of each particle depend on all other particles1. The lack of general solutions for the three-body problem and acceptable theory for strongly correlated electrons shows that our understanding of correlated systems fades when the particle number or the interaction strength increases. One of the hallmarks of interacting systems is the formation of multiparticle bound states2-9. Here we develop a high-fidelity parameterizable fSim gate and implement the periodic quantum circuit of the spin-½ XXZ model in a ring of 24 superconducting qubits. We study the propagation of these excitations and observe their bound nature for up to five photons. We devise a phase-sensitive method for constructing the few-body spectrum of the bound states and extract their pseudo-charge by introducing a synthetic flux. By introducing interactions between the ring and additional qubits, we observe an unexpected resilience of the bound states to integrability breaking. This finding goes against the idea that bound states in non-integrable systems are unstable when their energies overlap with the continuum spectrum. Our work provides experimental evidence for bound states of interacting photons and discovers their stability beyond the integrability limit.

Noise-resilient edge modes on a chain of superconducting qubits

Inherent symmetry of a quantum system may protect its otherwise fragile states. Leveraging such protection requires testing its robustness against uncontrolled environmental interactions. Using 47 superconducting qubits, we implement the one-dimensional kicked Ising model, which exhibits nonlocal Majorana edge modes (MEMs) with ℤ 2 parity symmetry. We find that any multiqubit Pauli operator overlapping with the MEMs exhibits a uniform late-time decay rate comparable to single-qubit relaxation rates, irrespective of its size or composition. This characteristic allows us to accurately reconstruct the exponentially localized spatial profiles of the MEMs. Furthermore, the MEMs are found to be resilient against certain symmetry-breaking noise owing to a prethermalization mechanism. Our work elucidates the complex interplay between noise and symmetry-protected edge modes in a solid-state environment.

Predicting the probability of malignant pathological type of kidney cancer based on mass size: A retrospective study

BACKGROUND

Different degrees of malignancy of renal cell carcinoma (RCC) correspond to dissimilar therapies, and the prediction of malignancy of kidney cancer based on tumor size is still not fully studied.

METHODS

We evaluated a total of 50,776 patients with T1-T2, N0, M0 RCC diagnosed between 2004 to 2015 based on the Surveillance, Epidemiology, and End Results database. Three and four fuhrman grade clear cell RCC, three and four fuhrman grade papillary RCC, collecting duct RCC, sarcomatoid differentiation RCC and unclassified RCC were classified as aggressive RCC. The other RCC was classified as indolent RCC. The probability of aggressive and indolent was estimated according to tumor size using a logistic regression model. Differences in survival between subgroups were assessed using the Kaplan-Meier method.

RESULTS

There were 38,003 cases of indolent tumor and 12,773 cases of aggressive tumor totally. As tumor size increases, the predicted probability of an aggressive tumor also increases. Concretely, kidney cancers of 2cm, 3cm and 4cm were estimated to be 19.6%, 21.6% and 23.7% more likely to be aggressive. And for the same tumor size, clear cell RCC in men is more likely to be invasive relative to women and other kidney cancer pathology types. In addition, both the overall and tumor-specific survival are longer for indolent tumors than for aggressive tumors.

CONCLUSION

We evaluated the degree of malignancy of different sizes RCC in a retrospective study. This result may be helpful in the choice of initial therapy strategies for kidney cancer patients.

Boosting the activity and stability via synergistic catalysis of Co nanoparticles and MoC to construct a bifunctional electrocatalyst for high-performance and long-life rechargeable zinc-air batteries

The high overpotential of the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) leading to slow air cathode kinetics is still a major challenge for zinc-air batteries (ZABs), hindering the commercialization of ZABs. With the advantages of cost-effectiveness and feasibility of synthesis at room temperature, zeolite imidazole frameworks (ZIFs) are regarded as advanced precursors. But a majority of ZIF-derived catalysts show only one catalytic activity, which limits their performance in ZABs as well as the cycling stability. In addition, molybdenum carbide (MoC) is recognized as an excellent candidate for renewable energy conversion due to its good chemical resistance and thermal stability. Herein, we report a ZIF-67-derived Co/MoC-NC multiphase doped carbon bifunctional ORR/OER catalyst with multiple active sites for the cathode of ZABs. The synergistic catalysis of Co nanoparticles and MoC nanoparticles in Co/MoC-NC which are embedded in a thin layer of N-doped graphitic carbon and immobilized on N-doped graphitic carbon, respectively, demonstrates superior ORR catalytic performance and durability both under alkaline and acidic conditions (E_1/2 = 0.87 V in 1.0 M KOH and E_1/2 = 0.76 V in 0.5 M H₂SO₄). Simultaneously, Co/MoC-NC also exhibits favorable OER performance (10 mA cm^-2, η = 320 mV) in 1 M KOH. Furthermore, a remarkable peak-power density of 215.36 mW cm^-2 and great cycling stability could be achieved while applying Co/MoC-NC in the cathode of ZABs (over 300 h). This work will provide a viable design concept for designing and synthesizing multifunctional catalysts to construct rechargeable ZABs.

[The surgical management of benign tumors of the lateral skull base with intracranial invasion: experience from a single centre over ten years]

Objective: To investigate the clinical features, pathological types, imaging features, and surgical strategies of lateral skull base benign tumors with intracranial invasion. Methods: From January 2011 to March 2021, 36 patients of lateral skull base benign tumors with intracranial invasion were included in this retrospective study. Among the 36 patients, 14 cases were male, 22 cases were female, the aged range from 20-67, with the median age of 48. The clinical manifestations, characteristic imaging findings, pathological types, surgical approach selection, and prognosis were analyzed. Results: 36 cases of lateral skull base tumors with intracranial invasion were all accepted surgeries. 23 cases were neurogenic tumors, facial nerve tumors (n=8), neurogenic tumors in jugular foramen with unknown origin(n=6), hypoglossal schwannoma (n=3), transotic intralabyrinthine schwannoma (n=3), vestibular schwannoma involving the middle ear(n=2), vagal nerve schwannoma(n=1). Other types of tumors included meningioma (n=10) and paraganglioma (Di 1 or 2,n=3). Different pathological types of tumors had different clinical manifestations and imaging manifestations. Sixteen cases were subjected to primary resection, while, other 20 cases underwent staged operation. Among the patients with staged operation, 10 patients had completed the second stage operation, five patients were waiting for the second stage operation, the other five patient's residual intracranial tumor were significantly reduced and the space between tumor and brain tissues widened after the first stage operation, so, the following up with "wait and scan"policy was suggested. The total resection rate of tumors was related to the pathological nature, in which neurogenic tumors were 15/17, and meningiomas were 5/8. The main postoperative complications were cerebrospinal fluid leakage and infection in the operation area. There were two cases of postoperative intracranial infection, and three cases of cerebrospinal fluid leakage occurred in non staged operation cases. Conclusions: Lateral skull base tumors with intracranial invasion are rare. The most common pathological type is schwannoma, followed by meningioma and paraganglioma. For this type of tumor, if there is infection in the operation area and neck invasion is large, it is suggested to choose staged surgery, which can reduce the risk of intracranial infection and the incidence of cerebrospinal fluid leakage. Staged surgery strategy can also reduce the difficulty of second stage surgery, so the operation is much safer than non staged surgery.

SuperSonic shear imaging for the differentiation between benign and malignant thyroid nodules: a meta-analysis

PURPOSE

To assess the diagnostic value of SuperSonic shear imaging (SSI) for the differentiation between benign and malignant thyroid nodules through meta-analysis.

METHODS

Online database searches were performed on PubMed, EMBASE, the Cochrane Library, and the Web of Science until 31 July 2021. The Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to assess the quality of the included studies. Three measures of diagnostic test performance were used to examine the value of SSI, including the summary area under the receiver operating characteristic curve (AUROC), the summary diagnostic odds ratio (DOR), and the summary sensitivity and specificity. Heterogeneity was explored using meta-regression and subgroup analyses.

RESULTS

Finally, 21 studies with 3376 patients were included in this study. There were a total of 4296 thyroid nodules, in which 1806 malignant nodules and 2490 benign ones were involved. Thyroid nodules exhibited a malignancy rate of 42.0% (range 5.6-79.8%), 95.1% of which were of papillary variant. SSI showed a summary sensitivity of 74% [95% confidence interval (CI) 67-79%], specificity of 82% (95% CI 77-87%) and AUROC of 0.85 (95% CI 0.82-0.88) for the differentiation between benign and malignant thyroid nodules. The summary positive likelihood ratio (LR), negative LR, and DOR were 4.2 (95% CI 3.3-5.3), 0.32 (95% CI 0.26-0.40), and 13 (95% CI 9-18), respectively.

CONCLUSIONS

SSI showed high accuracy in the diagnostic differentiation between benign and malignant thyroid nodules and can be served as a noninvasive and important adjunct for thyroid nodule evaluation.

[Construction of a risk assessment indicator system for re-establishment of imported malaria]

OBJECTIVE

To create a risk assessment indicator system for re-establishment of imported malaria.

METHODS

The risk assessment indicator system for re-establishment of imported malaria was preliminarily constructed through literature review and thematic discussions. A total of 26 malaria control experts were selected to carry out a two-round Delphi consultation of the indicator system. The active coefficient, authority coefficient and coordination coefficient of the experts and the coefficient of variation on each indicator were calculated for indicator screening and the weight of each indicator was calculated. The reliability of the indicator system was evaluated using Cronbach's coefficient α, and the content validity of the indicator system was evaluated using the authority coefficient of the expert, while the structural validity of the indicator system was evaluated using Kaiser-Meyer-Olkin (KMO) test and factor analysis.

RESULTS

Two rounds of Delphi expert consultations were completed by 23 malaria control experts, and a risk assessment indicator system for re-establishment of imported malaria was constructed, including 3 primary indicators, 7 secondary indicators, and 21 tertiary indicators. The active coefficient (100.00% vs. 88.46%; P < 0.01) and coordination coefficient of the expert (0.372 vs. 0.286; P < 0.01) were significantly greater in the second round of the Delphi expert consultation than in the first round. After the second round of the Delphi expert consultation, the authority coefficient of the experts ranged from 0.757 to 0.930 on each indicator, and the coefficients of variation were 0.098 to 0.136, 0.112 to 0.276 and 0.139 to 0.335 for the primary, secondary and tertiary indicators, respectively. The overall Cronbach's coefficient α of the indicator system was 0.941, and there were significant differences in the KMO values for primary (KMO value = 0.523; χ² = 18.192, P < 0.05), secondary (KMO value = 0.694, χ² = 51.499, P < 0.01) and tertiary indicators (KMO value = 0.519; χ² = 477.638, P < 0.01), while the cumulative contribution rate of six principal components in the tertiary indicators was 84.23%. The normalized weights of three primary indicators of the source of infection, transmission condition and control capability were 0.337, 0.333 and 0.329, and the three secondary indicators with the greatest normalized weights included the number of imported cases and malaria parasite species (0.160), introduction of imported cases in China and medical care seeking (0.152), vector species and density (0.152), while the five tertiary indicators with the greatest normalized weights included the malaria parasite species of imported cases (0.065), vector populations (0.064), and the time interval from onset to medical care seeking (0.059), number of imported cases (0.056), and the time interval from medical care seeking to definitive diagnosis (0.055).

CONCLUSIONS

A risk assessment indicator system for re-establishment of imported malaria is successfully created, which provides insights into the assessment of the risk of re-establishment of imported malaria and management of key high-risk factors in malaria-eliminated areas.

[Analysis of HIV-1 genetic subtype and pretreatment drug resistance among men who have sex with men infected with HIV-1 from 19 cities of 6 provinces in China]

Objective: To investigate the distribution of HIV-1 genetic subtypes and pretreatment drug resistance (PDR) among men who have sex with men (MSM) from 19 cities of 6 provinces in China. Methods: From April to November 2019, 574 plasma samples of ART-naive HIV-1 infected MSM were collected from 19 cities in Hebei, Shandong, Jiangsu, Zhejiang, Fujian, and Guangdong provinces, total ribonucleic acid (RNA) was extracted and amplified the HIV-1 pol gene region by nested polymerase chain reaction (PCR) after reverse transcription. Then sequences were used to construct a phylogenetic tree to determine genetic subtypes and submitted to the Stanford drug resistance database for drug resistance analysis. Results: A total of 479 samples were successfully amplified by PCR. The HIV-1 genetic subtypes included CRF01_AE, CRF07_BC, B, CRF55_01B, CRF59_01B, CRF65_cpx, CRF103_01B, CRF67_01B, CRF68_01B and unrecognized subtype, which accounted for 43.4%, 36.3%, 6.3%, 5.9%, 0.8%, 0.8%, 0.4%, 0.4%, 0.2% and 5.5%, respectively. The distribution of genetic subtypes among provinces is statistically different (χ²=44.141, P<0.001). The overall PDR rate was 4.6% (22/479), the drug resistance rate of non-nucleoside reverse transcriptase inhibitors, nucleoside reverse transcriptase inhibitors, and protease inhibitors were 3.5% (17/479), 0.8% (4/479) and 0.2% (1/479), respectively. The PDR rate of recent infections was significantly higher than that of long-term infections (χ²=4.634, P=0.031). Conclusions: The HIV-1 genetic subtypes among MSM infected with HIV-1 from 19 cities of 6 provinces in China are diverse, and the distribution of subtypes is different among provinces. The overall PDR rate is low, while the PDR rate of recent infections was significantly higher than that of long-term infections, suggesting the surveillance of PDR in recent infections should be strengthened.

Study of the Void Structure of PAN Fiber by Small Angle x-ray Scattering and Spline Function

The voids in fibers, especially in wet spun fibers are a major factor of fiber structure which greatly affects the fiber properties. A lot of research has shown that the inner voids and surface imperfections were the main causes of strength decreases. Therefore it is very important to determine the void morphology development in fiber processing in order to obtain high quality as-spun fiber.

In this paper we introduce a new method for the determination of void morphology using small angle x-ray scattering with a spline function method in which the average void size, size distribution and the related scattering power as well is obtained.

[Current research status on pelvic autonomic nerve monitoring in rectal cancer surgery]

Rectal cancer is a common malignant tumor of the digestive tract, and surgery is the main treatment strategy. Disorders of bowel, anorectal and urogenital function remain common problems after total mesorectal resection (TME), which seriously decreases the quality of life of patients. Surgical nerve damage is one of the main causes of the complications, while TME with pelvic autonomic nerve preservation is an effective way to reduce the occurrence of adverse outcomes. Intraoperative nerve monitoring (IONM) is a promising method to assist the surgeon to identify and protect the pelvic autonomic nerves. Nevertheless, the monitoring methods and technical standards vary, and the clinical use of IONM is still limited. This review aims to summarize the researches on IONM in rectal and pelvic surgery. The electrical nerve stimulation technique and different methods of IONM in rectal cancer surgery are introduced. Also, the authors discuss the limitations of current researches, including methodological disunity and lack of equipment, then prospect the future direction in this field.

[Application of limiting antigen avidity enzyme immunoassay for estimating HIV-1 incidence in men who have sex with men]

Objective: To estimate the incidence of HIV-1 infection in men who have sex with men (MSM) in key areas of China through HIV-1 limiting antigen avidity enzyme immunoassay (LAg-Avidity EIA), analyze the deviation from the actual results and identify influencing factors, and provided reference for improving the accuracy of estimation results. Methods: Based on the principle of the cohort randomized study design, 20 cities were selected in China based on population size and the number of HIV-positive MSM. The sample size was estimated to be 700 according to the HIV-1 infection rate in MSM. MSM mobile phone app. was used to establish a detection appointment and questionnaire system, and the baseline cross-sectional survey was conducted from April to November 2019. LAg-Avidity EIA was used to identify the recent infected samples. The incidence of HIV-1 infection was calculated and then adjusted based on the estimation formula designed by WHO. The influencing factors were identified by analyzing the sample collection and detection processes. Results: Among the 10 650 blood samples from the participants, 799 were HIV-positive in initial screening, in which 198 samples (24.78%) missed during confirmation test. Only 621 samples were received by the laboratory. After excluding misreported samples, 520 samples were qualified for testing. A total of 155 samples were eventually determined as recent infection through LAg-Avidity EIA; Based on the estimation formula , the incidence of HIV-1 infection in MSM in 20 cities was 4.06% (95%CI:3.27%-4.85%), it increased to 5.53% (95%CI: 4.45%-6.60%)after the adjusting for sample missing rate. When the sample missing rate and misreporting rate were both adjusted, the incidence of HIV-1 infection in the MSM increased to 5.66% (95%CI:4.67%-6.65%). The actual incidence of HIV-1 infection in MSM in the 20 cities might be between 4.06% and 5.66%. Conclusions: Sample missing and misreporting might cause the deviation of the estimation of HIV-1 infection incidence. It is important to ensure the sample source and the quality of sample collection and detection to reduce the deviation in the estimation of HIV-1 infection incidence.

A Hierarchical Bayesian Latent Class Model for the Diagnostic Performance of Mini-Mental State Examination and Montreal Cognitive Assessment in Screening Mild Cognitive Impairment Due to Alzheimer's Disease

BACKGROUND

The Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) are low costing and noninvasive neuropsychological tests in screening Mild Cognitive Impairment (MCI) due to Alzheimer's disease (AD). There is no consensus on which test performs better in detecting MCI due to AD based on the different imperfect reference standards. Therefore, we conducted a meta-analysis to assess the diagnostic performance of MMSE and MoCA for screening MCI due to AD in the absence of a gold standard.

METHODS

Six electronic databases were searched for relevant studies until April, 2022. A hierarchical Bayesian latent class model was used to estimate the pooled sensitivity and specificity of MoCA and MMSE in the absence of a gold standard.

RESULTS

90 eligible studies covering 21273 individuals for MMSE, 26631 individuals for MoCA were included in this meta-analysis. The pooled sensitivity was 0.71(95%CI: 0.67-0.74) for MMSE and 0.85(95%CI: 0.83-0.88) for MoCA, while the pooled specificity was 0.71(95%CI: 0.68-0.74) for MMSE and 0.79(95%CI: 0.76-0.81) for MoCA. MoCA was useful to "rule in" and "rule out" the diagnosis of MCI due to AD with higher positive likelihood ratio (4.07; 95%CI: 3.60-4.62) and lower negative likelihood ratio (0.18; 95%CI: 0.16-0.22). Moreover, the diagnostic odds ratio of MoCA was 22.08(95%CI: 17.24-28.29), which showed significantly favorable diagnostic performance.

CONCLUSIONS

It suggests that MoCA has greater diagnostic performance than MMSE for differentiating MCI due to AD when the gold standard is absent. However, these results should be taken with caution given the heterogeneity observed.

Realizing topologically ordered states on a quantum processor

[Figure: see text].