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Isoflurane is one of the most commonly used anaesthetic agents in surgery procedures. During the past decades, isoflurane has been found to cause impairment in neurological capabilities in new-borns and elderly patients. Luteolin is a flavonoid that has been documented to possess a neuroprotective effect. Here we investigated the putative neuroprotective effects of luteolin on isoflurane-induced neurotoxicity in mouse hippocampal neuronal HT22 cells and explored the potential mechanisms. We demonstrated that luteolin improved mitochondrial dysfunction and reduced oxidative stress and apoptosis in isoflurane-treated HT22 cells, and thus inhibiting the isoflurane-induced neuronal injury. Further investigations showed that isoflurane exposure caused miR-214 downregulation, which could be mitigated by treatment with luteolin. Knockdown of miR-214 attenuated the neuroprotection of luteolin on isoflurane-induced neuronal injury. More importantly, luteolin inhibited isoflurane-caused regulation of the PTEN/Akt pathway, while miR-214 knockdown altered the regulatory effect of luteolin on the PTEN/Akt pathway. Furthermore, the effects of miR-214 knockdown on the neuroprotection of luteolin could also be prevented by knockdown of PTEN, implying that the neuroprotective effect of luteolin was mediated by miR-214/PTEN/Akt signaling pathway. These findings provided evidence for the potential application of luteolin in preventing isoflurane-induced neurotoxicity.
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Hipocampo , Isoflurano , Luteolina , MicroRNAs , Neurônios , Fármacos Neuroprotetores , PTEN Fosfo-Hidrolase , Proteínas Proto-Oncogênicas c-akt , Transdução de Sinais , Animais , Isoflurano/toxicidade , Isoflurano/farmacologia , PTEN Fosfo-Hidrolase/metabolismo , Luteolina/farmacologia , Camundongos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , MicroRNAs/metabolismo , Fármacos Neuroprotetores/farmacologia , Transdução de Sinais/efeitos dos fármacos , Linhagem Celular , Estresse Oxidativo/efeitos dos fármacos , Apoptose/efeitos dos fármacosRESUMO
Despite being heralded as the "holy grail" of anodes for their high theoretical specific capacity, lithium (Li) metal anodes still face practical challenges due to difficulties in fabricating ultrathin Li with controllable thickness and suppressing Li dendrites growth. Herein, we introduce a simple and cost-effective dip-coating method to fabricate ultrathin lithium-tin (LiSn) anode with adjustable thicknesses ranging from 4.5 to 45 µm. The in situ formation of Li22Sn5 alloy improves the wettability of the molten Li, enabling the casting of ultrathin Li metal layers on different substrates. More importantly, the abundant Li22Sn5 lithiophilic sites significantly lower the nucleation overpotential, inducing uniform Li deposition and accelerating the electrochemical reaction at the interface. As a result, the symmetric cell assembled with LiSn-Cu electrodes can cycle stably for more than 120 h with a charge/discharge depth of 50%, which is 1.5 times longer than the lifespan of the pure Li anode. In the full cells paired with NCM cathode, the discharge specific capacity is improved from 13.84 to 70.31 mA h g-1 with the LiSn-Cu anode at 8 C. The LiSn-Cu||NCM full cell realized a high energy density of 724.9 Wh kg-1 at the active material level with an N/P ratio of 1.4.
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Optical thin films with high-reflectivity (HR) are essential for applications in quantum precision measurements. In this work, we propose a coating technique based on reactive magnetron sputtering with RF-induced substrate bias to fabricate HR-optical thin films. First, atomically flat SiO2 and Ta2O5 layers have been demonstrated due to the assistance of radio-frequency plasma during the coating process. Second, a distributed Bragg reflector (DBR) mirror with an HR of â¼99.999 328% centered at 1397 nm has been realized. The DBR structure is air-H{LH}19-substrate, in which the L and H denote a single layer of SiO2 with a thickness of 237.8 nm and a single layer of Ta2O5 with a thickness of 171.6 nm, respectively. This novel coating method would facilitate the development of HR reflectors and promote their wide applications in precision measurements.
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Histamine, an auto-reactive substance and mediator of inflammation, is synthesized from histidine through the action of histidine decarboxylase (HDC). It primarily acts on histamine receptors in the central nervous system (CNS). Increasing evidence suggests that histamine and its receptors play a crucial role in neuroinflammation, thereby modulating the pathology of neurodegenerative diseases. Recent studies have demonstrated that histamine regulates the phenotypic switching of microglia and astrocytes, inhibits the production of pro-inflammatory cytokines, and alleviates inflammatory responses. In the CNS, our research group has also found that histamine and its receptors are involved in regulating inflammatory responses and play a central role in ameliorating chronic neuroinflammation in neurodegenerative diseases. In this review, we will discuss the role of histamine and its receptors in neuroinflammation associated with neurodegenerative diseases, potentially providing a novel therapeutic target for the treatment of chronic neuroinflammation-related neurodegenerative diseases in clinical settings.
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Doenças Neurodegenerativas , Humanos , Doenças Neurodegenerativas/tratamento farmacológico , Histamina , Doenças Neuroinflamatórias , Sistema Nervoso Central , Inflamação/tratamento farmacológico , Inflamação/patologia , Microglia/patologiaRESUMO
AIM: To evaluate and compare postoperative ischemic complications to determine the risk factors for ischemic complications following revascularization surgery for Moyamoya disease (MMD). MATERIAL AND METHODS: This single-center retrospective study included 266 procedures between 2016 and 2021. Three types of revascularization approaches including direct bypass, indirect bypass, and combined bypass were performed. To identify risk factors for postoperative ischemic complications and contralateral cerebral infarction, preoperative clinical characteristics and radiographic features were examined using multivariate and ordinal logistic regression analyses. RESULTS: Postoperative ischemic complications occurred in 103 (6.6%) procedures. Ischemic presentation (p=0.001, odds ratios [OR] 5.59, 95% confidence interval [CI] 2.05-15.23), hypertension (p=0.030, OR 2.75, 95%CI 1.11- 6.83), advanced Suzuki stage (p=0.006, OR 3.19, 95%CI 1.40-7.26), and collateral circulation (p=0.001 OR 0.17, 95%CI 0.06-0.47) were risk factors for postoperative ischemic complications. Ordinal regression analysis revealed that unilateral involvement (p=0.043, OR 2.70, 95%CI 0.09-5.31), hemorrhagic presentation (p=0.013, OR 3.45, 95%CI 0.72-6.18), surgical approach (p=0.032, OR -1.38, 95%CI -2.65, -0.12), and collateral circulation [p=0.043, OR -1 .27, 95%CI -2.51, -0.04)] were associated with the type of ischemic complications. History of hypertension (p=0.031) and contralateral computed tomography (CT) perfusion stage (p=0.045) were associated with contralateral infarction. CONCLUSION: Inability of cerebral vessels to withstand changes in blood pressure induced by revascularization-related hemodynamic instability might be associated with postoperative complications in patients with Moyamoya disease.
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Revascularização Cerebral , Hipertensão , Doença de Moyamoya , Humanos , Doença de Moyamoya/complicações , Doença de Moyamoya/diagnóstico por imagem , Doença de Moyamoya/cirurgia , Estudos Retrospectivos , Fatores de Risco , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Revascularização Cerebral/efeitos adversos , Revascularização Cerebral/métodos , Hipertensão/epidemiologia , Hipertensão/complicações , Resultado do TratamentoRESUMO
Catalytic pyrolysis technology proves to be a highly effective approach for waste cooking oil management. However, high-pressure drops and easy deactivation of powder catalysts hinder the industrialization of this technology. In this study, a bifunctional SiC ball (ZSM-5/SiC ball structured) catalyst was prepared to produce monocyclic aromatics. Bifunctional SiC ball catalyst demonstrates notable microwave-responsive properties and remarkable catalytic efficacy. Results showed that the content of monocyclic aromatics under BFSB catalysis with microwave heating was the highest. Weight hourly space velocity is no longer one of the main factors affecting microwave-assisted catalytic pyrolysis under bifunctional SiC ball catalyst. Monocyclic aromatics content did not decrease significantly and was still higher than 86% when space velocity increased from 30 h-1 to 360 h-1. The highest space velocity could only be 180 h-1 under Powder ZSM-5, and the content of the monocyclic aromatics dropped rapidly to 67.68%. Furthermore, even after five operating cycles, the content of monocyclic aromatics with bifunctional SiC ball catalyst continues to surpass the initial content observed with Powder ZSM-5 at 500 °C and 180 h-1. Related characterizations revealed that coking is the primary cause of catalyst deactivation for both catalyst types; however, the bifunctional SiC ball catalyst exhibits a 29.1% lower occurrence of polyaromatic coke formation compared to Powder ZSM-5.
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Micro-Ondas , Pirólise , Pós , Biomassa , Catálise , Temperatura Alta , BiocombustíveisRESUMO
With the continuous advancement of urban renewal, the application of recycled aggregates (RA) is a win-win measure to solve the treatment of construction waste and provide the required building materials. However, the existence of a large amount of old adhesive mortar (OAM) makes it difficult for RA to equivalently replace natural aggregates (NA) due to their higher water absorption and crushing index, as well as a lower apparent density. From the published literature on enhancing RA, the most mature and easiest method for construction is physical enhancement technology. Therefore, through a review of recent related researches, this article summarizes and compares the modification effects of mechanical grinding technology, traditional heating and grinding technology, and microwave heating technology on the physical properties of RA, including water absorption, apparent density, and crushing value. The related modification mechanisms were discussed. Additionally, the impacts of different physical enhancement technologies on the environment and economy effects are assessed from the perspectives of carbon emissions and cost required during processing. Based on multi-criteria analysis, microwave heating technology is more efficient and cleaner, which is the most recommended in the future.
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Resíduos Industriais , Reciclagem , Resíduos Industriais/análise , Reciclagem/métodos , Materiais de Construção , Água , Desempenho Físico FuncionalRESUMO
With the implementation of garbage classification, perishable waste has become increasingly concentrated. This has led to a significant change in the VOC release characteristics at residential garbage collection points, posing a potential risk with unknown characteristics. This study investigated the release characteristics, odor pollution, and health risks of VOCs at garbage collection points under different classification effectiveness, seasons, garbage drop-off periods, and garbage collection point types. The results showed that the average concentration of VOCs released from the garbage sorting collection points (SPs) was 341.43 ± 261.16 µg/m3, and oxygenated compounds (e.g., ethyl acetate and acetone) were the main VOC components. The VOC concentration increased as the community classification effectiveness improved, and it was higher in summer (followed by spring, autumn, and winter). Moreover, the VOC concentrations were higher in the evenings than in the mornings and at centralized garbage collection points (CPs) than at SPs. Further, odor activity value (OAV) assessments indicated that acrolein, styrene, and ethyl acetate were the critical odorous components, with an average OAV of 0.87 ± 0.85, implying marginal odor pollution in some communities. Health risk assessments further revealed that trichloroethylene, benzene, and chlorotoluene were the critical health risk substances, with an average carcinogenic risk (CR) value of 10-6-10-4, and a non-carcinogenic risk (HI) value < 1. These results indicated that HIs were acceptable, but potential CRs existed in the communities. Therefore, VOC pollution prevention and control measures should be urgently strengthened at the garbage collection points in high pollution risk scenarios.
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Acetatos , Poluentes Atmosféricos , Compostos Orgânicos Voláteis , Monitoramento Ambiental/métodos , Poluentes Atmosféricos/análise , Compostos Orgânicos Voláteis/análise , ChinaRESUMO
BACKGROUND AND OBJECTIVE: Lysine and its pathway metabolites have been identified as novel biomarkers for metabolic and vascular diseases. The role of them in the identification of moyamoya disease (MMD) has not been elucidated. This study aimed to determine the association between lysine pathway metabolites and the presence of MMD. METHODS: We prospectively enrolled 360 MMD patients and 89 healthy controls from September 2020 to December 2021 in Beijing Tiantan Hospital. Serum levels of lysine, pipecolic acid and 2-aminoadipic acid were measured by liquid chromatography-mass spectrometry. We employed logistic regression and restricted cubic spline to explore the association between these metabolites and the presence of MMD. Stratified analyses were also conducted to test the robustness of results. RESULTS: We observed that lysine levels in MMD patients were significantly higher and pipecolic acid levels were significantly lower compared to HCs (both p < 0.001), while no difference was found in the level of 2-AAA between both groups. When comparing metabolites by quartiles, elevated lysine levels were linked to increased odds for MMD (the fourth quartile [Q4] vs the first quartile [Q1]: odds ratio, 3.48, 95%CI [1.39-8.75]), while reduced pipecolic acid levels correlated with higher odds (Q4 vs Q1: odds ratio, 0.08; 95 % CI [0.03-0.20]). The restricted cubic spline found a L-shaped relationship between pipecolic acid level and the presence of MMD, with a cutoff point at 2.52 µmol/L. Robust results were also observed across subgroups. CONCLUSION: Elevated lysine levels were correlated with increased odds of MMD presence, while lower pipecolic acid levels were associated with higher odds of the condition. These results suggest potential new biomarkers for the identification of MMD. CLINICAL TRIAL REGISTRY NUMBER: URL: https://www.chictr.org.cn/. Unique identifier: ChiCTR2200061889.
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Doença de Moyamoya , Humanos , Ácido 2-Aminoadípico , Biomarcadores , Lisina , Estudos Transversais , Estudos de Casos e ControlesRESUMO
OBJECTIVE: The optimal surgical approach for hemorrhagic moyamoya disease (hMMD) continues to be a topic of debate. The authors' prior research demonstrated that both combined and indirect revascularization were efficacious. However, questions remain regarding the long-term prognosis consistency between these two treatments. Therefore, the objective of this study was to evaluate and compare the enduring effects of these surgical modalities on adult hMMD, extending the findings of the authors' previous studies. METHODS: The authors recruited patients diagnosed with hMMD between 2010 and 2015. The patients were categorized into two groups: those who underwent combined revascularization (superficial temporal artery-middle cerebral artery bypass alongside dural reverse application) and those who underwent indirect revascularization (encephaloduroarteriosynangiosis [EDAS]). The primary and secondary endpoints of this study were instances of rebleeding, confirmed with CT scan, and death resulting from rebleeding, respectively. The authors estimated rebleeding-free and death-free survival rates by utilizing the Kaplan-Meier survival method. They used Cox regression to adjust for confounders and to evaluate the effects of the varying surgical modalities on the endpoints. RESULTS: After an average follow-up period of 114 months, 35 patients (28.6%) experienced 40 rebleeding events, yielding an average annual incidence of 3.5%. Of the 79 patients who received combined revascularization, 17 (21.5%) experienced rebleeding events. Similarly, of 43 patients who underwent EDAS, 18 (41.9%) experienced rebleeding events (p = 0.018). Most rebleeding instances occurred 61-120 months after surgery (21 patients [60%]), followed by 12-60 months (11 patients [31.4%]). Multivariate survival analysis highlighted significant differences in surgical outcomes (HR 0.33, 95% CI 0.15-0.74, p = 0.007). The authors observed that 8 patients (10.1%) died of rebleeding events in the combined group, as well as 10 patients (23.3%) in the EDAS group. Despite the lack of a statistically significant difference in mortality (p = 0.051), multivariable survival analysis found a significant difference (HR 0.31, 95% CI 0.10-0.97, p = 0.044). CONCLUSIONS: High rebleeding rates persist in adult hMMD patients, even after revascularization. Combined revascularization proved superior to EDAS in preventing long-term rebleeding. In contrast, EDAS alone did not display a clear effect on reducing long-term rebleeding rates.
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Revascularização Cerebral , Doença de Moyamoya , Adulto , Humanos , Seguimentos , Doença de Moyamoya/diagnóstico por imagem , Doença de Moyamoya/cirurgia , Procedimentos Cirúrgicos VascularesRESUMO
Objective. Convolutional neural networks (CNNs) have made significant progress in medical image segmentation tasks. However, for complex segmentation tasks, CNNs lack the ability to establish long-distance relationships, resulting in poor segmentation performance. The characteristics of intra-class diversity and inter-class similarity in images increase the difficulty of segmentation. Additionally, some focus areas exhibit a scattered distribution, making segmentation even more challenging.Approach. Therefore, this work proposed a new Transformer model, FTransConv, to address the issues of inter-class similarity, intra-class diversity, and scattered distribution in medical image segmentation tasks. To achieve this, three Transformer-CNN modules were designed to extract global and local information, and a full-scale squeeze-excitation module was proposed in the decoder using the idea of full-scale connections.Main results. Without any pre-training, this work verified the effectiveness of FTransConv on three public COVID-19 CT datasets and MoNuSeg. Experiments have shown that FTransConv, which has only 26.98M parameters, outperformed other state-of-the-art models, such as Swin-Unet, TransAttUnet, UCTransNet, LeViT-UNet, TransUNet, UTNet, and SAUNet++. This model achieved the best segmentation performance with a DSC of 83.22% in COVID-19 datasets and 79.47% in MoNuSeg.Significance. This work demonstrated that our method provides a promising solution for regions with high inter-class similarity, intra-class diversity and scatter distribution in image segmentation.
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COVID-19 , Humanos , COVID-19/diagnóstico por imagem , Redes Neurais de Computação , Processamento de Imagem Assistida por ComputadorRESUMO
OBJECTIVE: The objective of this retrospective study was to establish a novel system for evaluating collateralization of the external carotid artery in patients with moyamoya disease (MMD) following direct and indirect revascularization surgeries. METHODS: The authors conducted a retrospective analysis of 456 patients diagnosed with MMD who underwent direct and indirect revascularization procedures at Beijing Tiantan Hospital, Capital Medical University, between January 2015 and May 2023. Using a newly proposed digital subtraction angiography (DSA)-based evaluation system, the authors assessed collateralization angiogenesis objectively and in a standardized manner. RESULTS: The authors' findings indicated that there was no significant difference in collateralization angiogenesis between patients undergoing direct or indirect cerebral revascularization (p = 0.702). However, after cerebral revascularization, patients with ischemic MMD exhibited significantly higher collateralization angiogenesis compared with those with hemorrhagic MMD (p = 0.007). Children with MMD demonstrated higher angiogenesis levels than adults (p < 0.001), but subgroup analysis showed age-specific variations. In adults, collateralization angiogenesis was significantly greater in those with ischemic MMD (p = 0.006), whereas in children, no significant difference was noted between ischemic and hemorrhagic MMD (p = 0.962). Furthermore, regardless of MMD type, direct and indirect revascularization methods yielded similar collateralization angiogenesis (p = 0.962 and p = 0.963, respectively). Importantly, the Matsushima grading system revealed significant differences in angiogenesis in patients with ischemic MMD (p < 0.001). CONCLUSIONS: The newly introduced DSA-based evaluation system offers an objective and standardized method for assessing collateralization angiogenesis in MMD. This study supports the efficacy of both direct and indirect revascularization surgical procedures and highlights distinct pathophysiological processes of ischemic and hemorrhagic disease subtypes. These findings contribute to a better understanding of surgical outcomes and aid in the selection of appropriate treatment strategies for patients with MMD.
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Angiografia Digital , Artéria Carótida Externa , Revascularização Cerebral , Circulação Colateral , Doença de Moyamoya , Humanos , Doença de Moyamoya/cirurgia , Doença de Moyamoya/diagnóstico por imagem , Revascularização Cerebral/métodos , Masculino , Feminino , Estudos Retrospectivos , Adulto , Criança , Circulação Colateral/fisiologia , Pessoa de Meia-Idade , Adolescente , Adulto Jovem , Artéria Carótida Externa/cirurgia , Artéria Carótida Externa/diagnóstico por imagem , Pré-Escolar , Resultado do Tratamento , Neovascularização FisiológicaRESUMO
Optical anisotropy offers a heightened degree of flexibility in shaping optical properties and designing cutting-edge devices. Quasi-one-dimensional Ta2NiS5, with giant optical anisotropy, has been used in the development of new lasers and sensors. In this research endeavor, we successfully acquired the complete dielectric tensor of Ta2NiS5, utilizing the advanced technique of Mueller matrix spectroscopic ellipsometry, enabling a rigorous quantitative assessment of its optical anisotropy. The results indicate that Ta2NiS5 demonstrates giant birefringence and dichroism, with Δnmax = 1.54 and Δkmax = 1.80. This pursuit also delves into the fundamental underpinnings of this optical anisotropy, drawing upon a fusion of first-principles calculations and critical points analysis. The anisotropy of Ta2NiS5 arises from differences in optical transitions in different directions and is shown to be due to van Hove singularities without exciton effects. Its giant optical anisotropy is expected to be useful in the design of novel optical devices, and the revelation of the physical mechanism facilitates the modulation of its optical properties.
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Offline reinforcement learning (RL) optimizes the policy on a previously collected dataset without any interactions with the environment, yet usually suffers from the distributional shift problem. To mitigate this issue, a typical solution is to impose a policy constraint on a policy improvement objective. However, existing methods generally adopt a "one-size-fits-all" practice, i.e., keeping only a single improvement-constraint balance for all the samples in a mini-batch or even the entire offline dataset. In this work, we argue that different samples should be treated with different policy constraint intensities. Based on this idea, a novel plug-in approach named guided offline RL (GORL) is proposed. GORL employs a guiding network, along with only a few expert demonstrations, to adaptively determine the relative importance of the policy improvement and policy constraint for every sample. We theoretically prove that the guidance provided by our method is rational and near-optimal. Extensive experiments on various environments suggest that GORL can be easily installed on most offline RL algorithms with statistically significant performance improvements.
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Corona virus disease 2019 (COVID-19) is an acute respiratory infectious disease with strong contagiousness, strong variability, and long incubation period. The probability of misdiagnosis and missed diagnosis can be significantly decreased with the use of automatic segmentation of COVID-19 lesions based on computed tomography images, which helps doctors in rapid diagnosis and precise treatment. This paper introduced the level set generalized Dice loss function (LGDL) in conjunction with the level set segmentation method based on COVID-19 lesion segmentation network and proposed a dual-path COVID-19 lesion segmentation network (Dual-SAUNet++) to address the pain points such as the complex symptoms of COVID-19 and the blurred boundaries that are challenging to segment. LGDL is an adaptive weight joint loss obtained by combining the generalized Dice loss of the mask path and the mean square error of the level set path. On the test set, the model achieved Dice similarity coefficient of (87.81 ± 10.86)%, intersection over union of (79.20 ± 14.58)%, sensitivity of (94.18 ± 13.56)%, specificity of (99.83 ± 0.43)% and Hausdorff distance of 18.29 ± 31.48 mm. Studies indicated that Dual-SAUNet++ has a great anti-noise capability and it can segment multi-scale lesions while simultaneously focusing on their area and border information. The method proposed in this paper assists doctors in judging the severity of COVID-19 infection by accurately segmenting the lesion, and provides a reliable basis for subsequent clinical treatment.
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COVID-19 , Humanos , COVID-19/diagnóstico por imagem , Taxa Respiratória , Tomografia Computadorizada por Raios XRESUMO
OBJECTIVE: Patients with moyamoya disease (MMD) and fetal-type posterior cerebral arteries have not been thoroughly investigated as yet. We focused on the risk of intracranial hemorrhage in patients with MMD and fetal-type posterior cerebral arteries. METHODS: We reviewed 2422 patients with MMD diagnosed at the Neurosurgical Department of Beijing Tiantan Hospital between May 2009 and December 2020. We classified patients into 2 groups according to whether they had a fetal-type posterior cerebral artery. After 1:1 propensity score matching, hemorrhagic tendency and Suzuki stage were compared between patients with a fetal-type posterior cerebral artery (group I) and patients without a fetal-type posterior cerebral artery (group II). RESULTS: In total, 2415 patients were included in this study; 181 had fetal-type posterior cerebral arteries. Hemorrhagic events were more frequently observed in patients with fetal-type posterior cerebral artery development than in those without it (28.2% vs. 18.8%, P = 0.035). However, Suzuki stages did not differ between the 2 matched groups (4.03 vs. 4.20, P = 0.081). CONCLUSIONS: Hemorrhagic events occurred more frequently in patients with MMD with fetal-type posterior cerebral arteries than in those without.
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Revascularização Cerebral , Doença de Moyamoya , Humanos , Doença de Moyamoya/complicações , Doença de Moyamoya/diagnóstico por imagem , Doença de Moyamoya/cirurgia , Artéria Cerebral Posterior/diagnóstico por imagem , Artéria Cerebral Posterior/cirurgia , Pontuação de Propensão , Estudos Retrospectivos , Angiografia Cerebral , Hemorragias Intracranianas , Hemorragia Cerebral/diagnóstico por imagem , Hemorragia Cerebral/epidemiologia , Hemorragia Cerebral/etiologiaRESUMO
BACKGROUND: China has empowered and continues to empower internet hospitals, which saw an increase in their development due to the pandemic, to fight against COVID-19. The construction and operational models of internet hospitals can be categorized as self-constructed and self-managed models, self-constructed and enterprise-run models, hospital and enterprise joint-owned models, and hosted by a third-party platform. Despite the growing importance of internet hospitals, there have been few systematic summaries of their construction and operational models. The primary purpose of the study was to understand the construction and operational models of internet hospitals in China. METHODS: Data was collected from 39 internet hospitals and 356 medical staff between September 2020 and April 2021, via internet hospital and hospital staff surveys. T-tests were used to compare the continuous variables, while Chi-square tests were employed to compare the proportions of categorical variables. The self-perception of the internet hospitals' services was assessed using a 5-point Likert scale on 16 aspects and a root cause analysis was conducted to identify the root causes and influencing factors of current deficiencies experienced by internet hospitals. RESULTS: Among the 39 internet hospitals, 22 (56.4%) were self-constructed and self-managed. Compared to other models of Internet hospitals, self-constructed and self-managed hospitals had lower percentages of professionals providing online services (P = 0.006), numbers of doctors outside of the entity (P = 0.006), numbers of online nurses (P = 0.004), and the ratio of online nurses to offline doctors (P < 0.001). Of the 16 aspects evaluated with regards to the medical staff's self-perception of the internet hospital services, the highest scores were given for fee transparency, fee rationality, travel cost capital, patience and responsibility, and consultation behaviors. The root causes included five aspects: human, channels, prices, services, and time. CONCLUSIONS: While the self-constructed and self-managed model was found to be the most prevalent form of internet hospital in China, the different models of internet hospitals can have an impact on both the quantity and quality of online healthcare services. This study contributes to the existing literature on internet hospitals' construction and operational models, offering additional policy implications for telemedicine management.
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COVID-19 , Telemedicina , Humanos , COVID-19/epidemiologia , Hospitais , Pandemias , China/epidemiologia , InternetRESUMO
The refractive index is a critical parameter in optical and photonic device design. However, due to the lack of available data, precise designs of devices working in low temperatures are still frequently limited. In this work, we have built a homemade spectroscopic ellipsometer (SE) and measured the refractive index of GaAs at a matrix of temperatures (4 K < T < 295 K) and photon wavelengths (700 nm < λ < 1000 nm) with a system error of â¼0.04. We verified the credibility of the SE results by comparing them with afore-reported data at room temperature and with higher precision values measured by vertical GaAs cavity at cryogenic temperatures. This work makes up for the lack of the near-infrared refractive index of GaAs at cryogenic temperatures and provides accurate reference data for semiconductor device design and fabrication.
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Fótons , Refratometria , Temperatura , SemicondutoresRESUMO
BACKGROUND: Coexistence of intracranial atherosclerotic stenosis (ICAS) and unruptured intracranial aneurysms (UIAs) is increasingly encountered in clinical practice. This study aims to determine the prevalence of ICAS in patients with UIAs and procedural ischemic risk associated with ICAS when treating UIAs. METHODS: Based on the CAIASA study (Coexistence of Atherosclerotic Intracranial Arterial Stenosis With Intracranial Aneurysms), we prospectively included patients undergoing treatment procedures for UIAs from October 2015 to December 2020 at Beijing Tiantan Hospital, China. We used computed tomography angiography or digital subtraction angiography to diagnose ICAS (stenosis≥50%). Multivariable logistic regression and propensity-score matching were performed to evaluate the risk of procedure-related ischemic stroke and unfavorable outcome associated with ICAS. The ICAS score was used to explore the association between different burden of ICAS and procedure-related ischemic risk. RESULTS: Among 3949 patients who underwent endovascular or open surgical procedures for UIAs, 245 (6.2%) had ICAS. After exclusion, 15.7% (32/204) of patients with ICAS experienced procedure-related ischemic stroke compared with 5.0% (141/2825) of patients without ICAS. From the unmatched and matched cohort, ICAS was significantly associated with increased risk of procedure-related ischemic stroke (unmatched: adjusted odds ratio=3.11 [1.89-5.11]; and matched: adjusted odds ratio=2.99 [1.38-6.48]). This association became more evident among patients not receiving antiplatelet therapy (Pinteraction=0.022). For patients undergoing different treatment modalities, similar increased risks were observed (clipping: adjusted odds ratio=3.43 [1.73-6.79]; and coiling: adjusted odds ratio=3.59 [1.94-6.65]). Higher ICAS score was correlated with higher procedural ischemic risk (Ptrend<0.001). CONCLUSIONS: The occurrence of ICAS is not infrequent in patients with UIAs. ICAS confers an ~2-fold increased procedural ischemic risk, irrespective of clipping or coiling. Previous antiplatelet therapy may decrease the risk. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT02795078.
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Aneurisma Intracraniano , Arteriosclerose Intracraniana , AVC Isquêmico , Humanos , Constrição Patológica/diagnóstico por imagem , Constrição Patológica/epidemiologia , Constrição Patológica/complicações , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/epidemiologia , Aneurisma Intracraniano/cirurgia , Arteriosclerose Intracraniana/diagnóstico por imagem , Arteriosclerose Intracraniana/epidemiologia , Arteriosclerose Intracraniana/complicações , AVC Isquêmico/complicações , Inibidores da Agregação Plaquetária/uso terapêutico , Prevalência , Fatores de RiscoRESUMO
X-ray tomography is a non-destructive imaging technique that reveals the interior of an object from its projections at different angles. Under sparse-view and low-photon sampling, regularization priors are required to retrieve a high-fidelity reconstruction. Recently, deep learning has been used in X-ray tomography. The prior learned from training data replaces the general-purpose priors in iterative algorithms, achieving high-quality reconstructions with a neural network. Previous studies typically assume the noise statistics of test data are acquired a priori from training data, leaving the network susceptible to a change in the noise characteristics under practical imaging conditions. In this work, we propose a noise-resilient deep-reconstruction algorithm and apply it to integrated circuit tomography. By training the network with regularized reconstructions from a conventional algorithm, the learned prior shows strong noise resilience without the need for additional training with noisy examples, and allows us to obtain acceptable reconstructions with fewer photons in test data. The advantages of our framework may further enable low-photon tomographic imaging where long acquisition times limit the ability to acquire a large training set.