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Quantum many-body scars are nonthermal excited eigenstates of nonintegrable Hamiltonians, which could support coherent revival dynamics from special initial states when scars form an equally spaced tower in the energy spectrum. For open quantum systems, engineering many-body scarred dynamics by a controlled coupling to the environment remains largely unexplored. Here, we provide a general framework to exactly embed quantum many-body scars into the decoherence-free subspaces of Lindblad master equations. The dissipative scarred dynamics manifest persistent periodic oscillations for generic initial states, and can be practically utilized to prepare scar states with potential quantum metrology applications. We construct the Liouvillian dissipators with the local projectors that annihilate the whole scar towers, and utilize the Hamiltonian part to rotate the undesired states out of the null space of dissipators. We demonstrate our protocol through several typical models hosting many-body scar towers and propose an experimental scheme to observe the dissipative scarred dynamics based on digital quantum simulations and resetting ancilla qubits.
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We propose a machine-learning inspired variational method to obtain the Liouvillian gap, which plays a crucial role in characterizing the relaxation time and dissipative phase transitions of open quantum systems. By using "spin bi-base mapping," we map the density matrix to a pure restricted-Boltzmann-machine (RBM) state and transform the Liouvillian superoperator to a rank-two non-Hermitian operator. The Liouvillian gap can be obtained by a variational real-time evolution algorithm under this non-Hermitian operator. We apply our method to the dissipative Heisenberg model in both one and two dimensions. For the isotropic case, we find that the Liouvillian gap can be analytically obtained and in one dimension even the whole Liouvillian spectrum can be exactly solved using the Bethe ansatz method. By comparing our numerical results with their analytical counterparts, we show that the Liouvillian gap could be accessed by the RBM approach efficiently to a desirable accuracy, regardless of the dimensionality and entanglement properties.
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Background: Emerging evidence suggests the potential relationship between vitamin D deficiency and risk of cognitive impairment or dementia. To what extent the excess risk of dementia conferred by vitamin D deficiency is less clear. Objective: We summarized the current evidence from several aspects and further quantified these associations. Methods: We collected relevant prospective cohort studies by searching PubMed, Embase and Cochrane up to July 2023. The pooled relative risks (RR) were evaluated by random-effects models. Dose-response analyses were conducted by the method of two-stage generalized least squares regression. Results: Of 9,267 identified literatures, 23 were eligible for inclusion in the meta-analyses, among which 9 and 4 literatures were included in the dose-response analyses for the risk of dementia and Alzheimer's disease (AD). Vitamin D deficiency exhibited a 1.42 times risk for dementia (95% confidence interval (CI)â=â1.21-1.65) and a 1.57-fold excess risk for AD (95% CIâ=â1.15-2.14). And vitamin D deficiency was associated with 34% elevated risk with cognitive impairment (95% CIâ=â1.19-1.52). Additionally, vitamin D was non-linearly related to the risk of dementia (pnonlinearityâ=â0.0000) and AD (pnonlinearityâ=â0.0042). The approximate 77.5-100ânmol/L 25-hydroxyvitamin D [25(OH)D] was optimal for reducing dementia risk. And the AD risk seemed to be decreased when the 25(OH)D level >40.1ânmol/L. Conclusions: Vitamin D deficiency was a risk factor for dementia, AD, and cognitive impairment. The nonlinear relationships may further provide the optimum dose of 25(OH)D for dementia prevention.
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Disfunção Cognitiva , Demência , Deficiência de Vitamina D , Vitamina D , Humanos , Vitamina D/sangue , Disfunção Cognitiva/sangue , Disfunção Cognitiva/epidemiologia , Deficiência de Vitamina D/complicações , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/epidemiologia , Demência/epidemiologia , Demência/sangue , Estudos Prospectivos , Fatores de Risco , Doença de Alzheimer/sangue , Doença de Alzheimer/epidemiologiaRESUMO
BACKGROUND: Novel coronavirus pneumonia has been the most serious worldwide public health emergency since being identified in December 2019. The rapid spread of the pandemic and the strong human to human infection rate of COVID-19 poses a great prevention challenge. There has been an explosion in the number of confirmed cases in several cities near Wuhan, including the highest in Honghu, Jinzhou. Owing to the limited admission capacity and medical resources, increasing numbers of suspected cases of COVID-19 infection were difficult to confirm or treat. CASE PRESENTATION: Following the arrival of the Guangdong medical aid team on 11 February, 2020, COVID-19 care in Honghu saw changes after a series of solutions were implemented based on the 'Four-Early' and 'Four-centralization' management measures. The 'Four-Early' measures are: early detection, early reporting, early quarantine, and early treatment for meeting an urgent need like the COVID-19 pandemic. 'Four-centralization' refers to the way in which recruited medical teams can make full use of medical resources to give patients the best treatment. These solutions successfully increased the recovery rate and reduced mortality among patients with COVID-19 in Honghu. CONCLUSIONS: This management strategy is called the 'Honghu Model' which can be generalized to enable the prevention and management of COVID-19 worldwide.
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COVID-19/prevenção & controle , COVID-19/epidemiologia , China/epidemiologia , Cidades/epidemiologia , Hospitalização , Humanos , Pandemias/prevenção & controle , Administração dos Cuidados ao Paciente , Saúde Pública , Quarentena , SARS-CoV-2/isolamento & purificaçãoRESUMO
INTRODUCTION: Stage IIB cervical cancer (CC) is an advanced stage CC with poor prognosis. Inflammatory response plays a crucial role in the development of CC, and systemic inflammatory indexes were related to the prognosis in several cancers. The objective of the study was to determine the prognostic value of platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), basophil-to-lymphocyte ratio (BLR), and systemic inflammation response index (SIRI) as inflammatory indexes in patients with stage IIB CC. MATERIALS AND METHODS: A retrospective study was performed in 260 patients with stage IIB CC. PLR, NLR, MLR, BLR, and SIRI were obtained from routine blood tests. Prognosis information of the patients was acquired from regular clinical follow-up. Recurrence and response to therapy were determined through electronic medical records (EMRs). Correlations of the inflammatory indexes with overall survival (OS), progression-free survival (PFS), recurrence, and response to therapy were analyzed using SPSS version 26.0 software. RESULTS: Receiver operating characteristic (ROC) curve analyses suggested that NLR, MLR, and SIRI had better predictive value than PLR as well as BLR in the prognosis and recurrence risk. Both univariate and multivariate survival analyses showed that higher NLR and MLR were significantly associated with shorter OS as well as PFS, whereas SIRI was not an independent predictive factor of PFS. Chi-square test results revealed that increased NLR was significantly correlated with higher recurrence rate (P=0.046), and increased MLR showed significant correlation with elevated recurrence risk (P=0.002). Univariate and binary logistic regression analyses for response to therapy indicated that elevated NLR was associated with decreased complete remission (CR) rate (P=0.031), and the P value lost statistical significance while being adjusted by tumor size (P=0.108). CONCLUSIONS: For patients with stage IIB CC, both NLR and MLR are independent prognostic factors as well as risk factors for recurrence; NLR serves as a potential marker for therapeutic response.
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OBJECTIVE: To evaluate the effectiveness and safety of Songling Xuemaikang Capsule (, SXC) for the treatment of primary hypertension. METHODS: An extensive search including Cochrane Library, PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Chinese Biomedical Literature Database (CBM), Chinese National Knowledge Infrastructure (CNKI), Chinese Scientific Journal Database (VIP), KoreaMed, Japanese database, and online clinical trial registry websites was performed up to February 2013. Randomized controlled trials (RCTs) regarding SXC for the treatment of primary hypertension were searched without no language restrictions. The quality of each trial was assessed according to the Cochrane Reviewers' Handbook 5.0, and RevMan 5.0 provided by the Cochrane Collaboration. RESULT: A total of 17 RCTs involving 1,778 patients were included. Meta-analysis showed that there was no significant difference between SXC and antihypertensive agents on systolic blood pressure [mean difference (MD): -0.10 [-4.83, 4.63]; P=0.97] and diastolic blood pressure (MD: 1.00 [-1.16, 3.16]; P=0.36), but SXC combined with antihypertensive drugs was more effective in lowering systolic blood pressure (MD: -6.17 [-7.86, -4.49]; P<0.00001) and diastolic blood pressure (MD: -7.24 [-8.62, -5.85]; P<0.00001) compared with the antihypertensive drugs alone. CONCLUSIONS: SXC used alone or combined with antihypertensive drugs appear to be an effective treatment for lowering elevated blood pressure and improving symptoms in patients with primary hypertension. However, the conclusion cannot be drawn definitely due to the poor quality of the included studies. There is still an urgent need for well-designed, long-term studies to address the benefits of SXC for treating primary hypertension.