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Interest of D-dimer level,severity of COVID-19 and cost of management in Gabon
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作者 Berthe A Iroungou Arnaud Nze O +4 位作者 Helga M Kandet Y Neil-Michel Longo-Pendy Nina D Mezogho-Obame Annicet-Clotaire Dikoumba Guignali L Mangouka 《World Journal of Critical Care Medicine》 2025年第1期91-99,共9页
BACKGROUND Coronavirus disease 2019(COVID-19)is strongly associated with an increased risk of thrombotic events,including severe outcomes such as pulmonary embolism.Elevated D-dimer levels are a critical biomarker for... BACKGROUND Coronavirus disease 2019(COVID-19)is strongly associated with an increased risk of thrombotic events,including severe outcomes such as pulmonary embolism.Elevated D-dimer levels are a critical biomarker for assessing this risk.In Gabon,early implementation of anticoagulation therapy and D-dimer testing has been crucial in managing COVID-19.This study hypothesizes that elevated Ddimer levels are linked to increased COVID-19 severity.AIM To determine the impact of D-dimer levels on COVID-19 severity and their role in guiding clinical decisions.METHODS This retrospective study analyzed COVID-19 patients admitted to two hospitals in Gabon between March 2020 and December 2023.The study included patients with confirmed COVID-19 diagnoses and available D-dimer measurements at admission.Data on demographics,clinical outcomes,D-dimer levels,and healthcare costs were collected.COVID-19 severity was classified as non-severe(outpatients)or severe(inpatients).A multivariable logistic regression model was used to assess the relationship between D-dimer levels and disease severity,with adjusted odds ratios(OR)and 95%CI.RESULTS A total of 3004 patients were included,with a mean age of 50.17 years,and the majority were female(53.43%).Elevated D-dimer levels were found in 65.81%of patients,and 57.21%of these experienced severe COVID-19.Univariate analysis showed that patients with elevated D-dimer levels had 3.33 times higher odds of severe COVID-19(OR=3.33,95%CI:2.84-3.92,P<0.001),and this association remained significant in the multivariable analysis,adjusted for age,sex,and year of collection.The financial analysis revealed a substantial burden,particularly for uninsured patients.CONCLUSION D-dimer predicts COVID-19 severity and guides treatment,but the high cost of anticoagulant therapy highlights the need for policies ensuring affordable access in resource-limited settings like Gabon. 展开更多
关键词 d-dimerS COVID-19 MANAGEMENT Disease severity Healthcare costs GABON
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D-dimer level and long-term outcome in patients with end-stage heart failure secondary to idiopathic dilated cardiomyopathy 被引量:10
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作者 Bi HUANG Yuan-Jing LI +3 位作者 Jian SHEN Yuan YANG Gang LIU Su-Xin LUO 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2019年第8期621-629,共9页
Background Previous studies had demonstrated hemostatic abnormalities in patients with heart failure (HF) and several studies have shown that abnormal coagulation indices, represented by elevated D-dimer, had prognost... Background Previous studies had demonstrated hemostatic abnormalities in patients with heart failure (HF) and several studies have shown that abnormal coagulation indices, represented by elevated D-dimer, had prognostic significance in patients with compatible or acute decompensated HF. However, the impact of D-dimer on the outcome in patients with end-stage HF remains unclear. Methods A total of 244 consecutive patients with end-stage HF due to idiopathic dilated cardiomyopathy (DCM) were prospectively enrolled from February 2011 to September 2014. D-dimer levels were measured and its prognostic value was assessed. Primary endpoint was all-cause mortality during the follow-up period. Secondary endpoints were stroke, bleeding, occurrence of sustained ventricular tachycardia or ventricular fibrillation, and major adverse cardiovascular events (MACE). Results D-dimer was significantly elevated in the non-survivors (median: 0.8 vs. 1.1 mg/L, P < 0.001). Traditional markers including B-type natriuretic peptide, troponin I, left ventricular ejection fraction, and left ventricular end-diastolic dimension provided limited prognostic value;but the addition of D-dimer refined the risk stratification. The optimal cut-off value of D-dimer to predict all-cause mortality was 0.84 mg/L by receiver operator characteristic analysis. Elevated D-dimer level was independently associated with increased risk of long-term all-cause mortality (HR = 2.315, 95% CI: 1.570–3.414, P < 0.001) and MACE (HR = 1.256, 95% CI: 1.058–1.490, P = 0.009), and the predictive value was independent of age, sex, atrial fibrillation and anticoagulation status. Conclusions Elevated D-dimer level was independently associated with poor long-term outcome in patients with end-stage HF secondary to idiopathic DCM, and the predictive value was superior to that of traditional prognostic markers. 展开更多
关键词 d-dimer END-STAGE heart failure IDIOPATHIC DILATED CARDIOMYOPATHY Long-term OUTCOME
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Plasma D-dimer level in early and late-onset neonatal sepsis 被引量:10
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作者 Mohammed Al-Biltagi Ehab M Hantash +3 位作者 Mohammed Ramadan El-Shanshory Enayat Aly Badr Mohamed Zahra Manar Hany Anwar 《World Journal of Critical Care Medicine》 2022年第3期139-148,共10页
BACKGROUND Neonatal sepsis is a life-threatening disease.Early diagnosis is essential,but no single marker of infection has been identified.Sepsis activates a coagulation cascade with simultaneous production of the D-... BACKGROUND Neonatal sepsis is a life-threatening disease.Early diagnosis is essential,but no single marker of infection has been identified.Sepsis activates a coagulation cascade with simultaneous production of the D-dimers due to lysis of fibrin.Ddimer test reflects the activation of the coagulation system.AIM To assess the D-dimer plasma level,elaborating its clinicopathological value in neonates with early-onset and late-onset neonatal sepsis.METHODS The study was a prospective cross-sectional study that included ninety neonates;divided into three groups:Group I:Early-onset sepsis(EOS);Group II:Late-onset sepsis(LOS);and GroupⅢ:Control group.We diagnosed neonatal sepsis according to our protocol.C-reactive protein(CRP)and D-dimer assays were compared between EOS and LOS and correlated to the causative microbiological agents.RESULTS D-dimer was significantly higher in septic groups with a considerably higher number of cases with positive D-dimer.Neonates with LOS had substantially higher levels of D-dimer than EOS,with no significant differences in CRP.Neonates with LOS had a significantly longer hospitalization duration and higher gram-negative bacteriemia and mortality rates than EOS(P<0.01).Gramnegative bacteria have the highest D-dimer levels(Acinetobacter,Klebsiella,and Pseudomonas)and CRP(Serratia,Klebsiella,and Pseudomonas);while gram-positive sepsis was associated with relatively lower levels.D-dimer had a significant negative correlation with hemoglobin level and platelet count;and a significant positive correlation with CRP,hospitalization duration,and mortality rates.The best-suggested cut-off point for D-dimer in neonatal sepsis was 0.75 mg/L,giving a sensitivity of 72.7%and specificity of 86.7%.The D-dimer assay has specificity and sensitivity comparable to CRP in the current study.CONCLUSION The current study revealed a significant diagnostic value for D-dimer in neonatal sepsis.D-dimer can be used as an adjunct to other sepsis markers to increase the sensitivity and specificity of diagnosing neonatal sepsis. 展开更多
关键词 Early-onset neonatal sepsis Late-onset neonatal sepsis C-reactive protein d-dimer
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Evaluation of D-Dimer Level in Sudanese Patients with Chronic Liver Disease in IbnSina Hospital 被引量:2
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作者 Rehab Abdul Kareem Ahmed Al-Basheer Amira Ahmed Khalid Humeida 《Open Journal of Internal Medicine》 2017年第3期74-79,共6页
Background: Chronic liver disease is a disease process of the liver that involves a process of progressive destruction and regeneration of the liver parenchyma leading to fibrosis and cirrhosis chronic liver disease r... Background: Chronic liver disease is a disease process of the liver that involves a process of progressive destruction and regeneration of the liver parenchyma leading to fibrosis and cirrhosis chronic liver disease refers to disease of the liver which had lasted over a period of 6 months. This study was conducted to evaluate the D-dimer levels among Sudanese patients with Chronic Liver Diseases. Materials and Method: In IbnSina hospital, Khartoum state, Sudan, a case control study was conducted. For this study, 100 participants were selected, 70 of them were patients known diagnosed by chronic liver diseases as a test group. Other 30 participants were normal healthy individual as control group. The plasma D-dimer level was measured by using MINDRAY auto analyzer BS 380). Results: In this study, the plasma D-dimer level has statistically significantly higher in chronic liver diseases patients (mean ± SD 0.634 ± 0.215 ug/l) compared to normal healthy control group (mean ± SD 0.223 ± 0.077 ug/l) with P value 0.000. Conclusion: The present study revealed that the D-dimer levels were statistically significant higher in chronic liver diseases patients. 展开更多
关键词 CHRONIC Liver Disease COAGULATION d-dimer SUDAN
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Estimation and Assessment of Plasma D-Dimer Levels in HIV Patients 被引量:1
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作者 Wafa Hamid Haroun Himmat Nasr Eldeen Ali Mohammed Gaufri 《Journal of Biosciences and Medicines》 2016年第10期1-5,共6页
Background: The elevation of plasma D-dimer levels is fully described and associated with the increase of the mortality of patients with HIV. The present study was aimed to estimate and assess the plasma D-dimer level... Background: The elevation of plasma D-dimer levels is fully described and associated with the increase of the mortality of patients with HIV. The present study was aimed to estimate and assess the plasma D-dimer levels in HIV patient. Material and Methods: A case control study done in May 2015. A total of 100 subjects were enrolled in this study;50 were patients professionally diagnosed by HIV;25 (50%) were males and 25 (50%) were females;their mean age is 35 years. Further 50 normal healthy individuals as normal control group: their gender and age were matched with patient groups. The platelets poor plasma (PPP) was immediately prepared from citrated blood, then the plasma D-dimer level was measured using (MISPA-i<sub>2</sub> Reagent) Switzerland. Data were analyzed using statistical packing for social sciences program (SPSS) 20. Results: The D-dimer levels was significantly higher in patient with HIV compared with the normal healthy control group (Mean and STD 502.2 ± 287.8 vs 251.8 ± 152.7 P. value 0.01). Conclusion: The D-dimer level was significantly higher in patient with HIV compared with those in normal healthy control group. 展开更多
关键词 HIV AIDS d-dimer SUDAN
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Relationship between Radiological Lung Findings and Laboratory Ferritin and D-Dimer Levels in Patients with COVID-19 Infection 被引量:1
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作者 Mona F. Kardus Rana A. Hallak +5 位作者 Ahmed Alakedi Noha Yusef Sindi Hadeel Abdullah Alhawas Shine Rashed Hessa Al-Twalah Ibrahim Khoja 《International Journal of Clinical Medicine》 CAS 2022年第10期468-477,共10页
Introduction: Pulmonary symptoms of COVID-19 infection range from asymptomatic infection to severe pneumonia. Pathogenesis and severity of symptoms were found to be related to the body’s immune response. Objectives: ... Introduction: Pulmonary symptoms of COVID-19 infection range from asymptomatic infection to severe pneumonia. Pathogenesis and severity of symptoms were found to be related to the body’s immune response. Objectives: Ferritin and D-Dimer in COVID-19 confirmed cases can predict lung injury and possible poor patient prognosis. Materials and Methods: Patients who had been admitted to Dr. Sulaiman Alhabib-Arryan Hospital with positive COVID-19 polymerase chain reaction (PCR) tests between March 2020 and December 2021 were studied for blood ferritin and D-Dimer levels in relation to pulmonary radiological findings. Results: A total of 494 cases are included in this study. Male patients represent 74.1% of the cases, and the mean age is 51.68 ± 13.37 years. Increased age, ferritin, D-Dimer levels, and respiratory symptoms are factors that showed a statistically significant association with positive computed tomography (CT) findings. Receiver operator characteristic curve (ROC) showed that ferritin has a higher capability than D-Dimer to detect CT findings and that both are equal in predicting possible patient mortality. Suggested cutoff values for Ferritin > 336 ng/mL, with 78.21% sensitivity and 86.42% specificity and for D-Dimer > 0.55 mg/L FEU, with sensitivity of 74.82% and specificity of 75.31%. For mortality, the suggested cutoff point for ferritin is >864.6 ng/mL, which gives a sensitivity of 80.26 and a specificity of 64.83%. The suggested cutoff point for D-Dimer is >1.46 mg/L FEU, which gives a sensitivity of 65.79% and a specificity of 78.23%. Conclusion: Laboratory markers such as Ferritin and D-Dimer can be an accurate predictor of lung injury in COVID-19 patients and their increased values can predict the poor patient prognosis and possible mortality if aggressive hospital care is not provided. 展开更多
关键词 FERRITIN COVID-19 d-dimer
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Clinical laboratory investigation of a patient with an extremely high D-dimer level:A case report
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作者 Han-Xiao Sun Hong Ge +1 位作者 Zhong-Qing Xu Hui-Ming Sheng 《World Journal of Clinical Cases》 SCIE 2020年第16期3560-3566,共7页
BACKGROUND D-dimer,a soluble degradation product of cross-linked fibrin,is commonly used as an important marker for the diagnosis of disseminated intravascular coagulation and differential diagnosis of thrombosis.Here... BACKGROUND D-dimer,a soluble degradation product of cross-linked fibrin,is commonly used as an important marker for the diagnosis of disseminated intravascular coagulation and differential diagnosis of thrombosis.Herein,we present a geriatric case with an unusually elevated D-dimer level.CASE SUMMARY An 82-year-old woman,admitted to the ward with a diagnosis of chronic heart failure,was noted to have a remarkably elevated D-dimer level,beyond the qualified range(>100 mg/L),utilizing the Innovating D-dimer for Sysmex CS-5100 System?.However,no evidence,including clinical symptoms,radiographic evidence of thromboembolic disease,and parallel fibrinogen degradation product values,suggested that this patient was at high risk of thrombopenia.To confirm the discrepancy,a series of approaches including sample dilution,re-analysis via alternative methods,and sample treatment with blockage of specific heterophilic antibodies were performed.A remarkable disappearance of the elevated D-dimer values was observed in the samples after they were subjected to these approaches(4.49,9.42,9.06,and 12.58 mg/L,respectively).This confirmed the presence of heterophilic antibodies in this case.In addition,a reduction in cardiac output due to the presence of cardiac failure could also be responsible for the existence of a hypercoagulable state in this case.CONCLUSION In conclusion,the presence of heterophilic antibodies should be considered when an elevated D-dimer value is not in conformity with the clinical evidence,and a viral infection should be considered when interference by a heterophilic antibody exists. 展开更多
关键词 d-dimer Heterophilic antibodies Epstein-Barr virus Case report
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Correlation of Preoperative D-Dimer Levels and Postoperative Venous Thromboembolism in Patients Undergoing Total Hip Arthroplasty and Total Knee Arthroplasty
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作者 Sanjay Agarwala Mayank Vijayvargiya Neeraj Mishra 《Open Journal of Orthopedics》 2021年第9期269-277,共9页
<b>Background:</b><span "=""> The relationship of preoperative D-dimer and Venous thromboembolism (VTE) after total knee arthroplasty (TKA) and total hip arthroplasty (THA) remains con... <b>Background:</b><span "=""> The relationship of preoperative D-dimer and Venous thromboembolism (VTE) after total knee arthroplasty (TKA) and total hip arthroplasty (THA) remains controversial. The purpose of this study was to assess the value of D-dimer in the detection of early VTE after TKA and THA. <b>Materials and Methods:</b> A total of 312 patients were evaluated in this retrospective study from 2016 to 2020 at a tertiary care centre, Mumbai who were operated for THA and TKA. The measurement of plasma D-dimer level was done preoperatively and clinically symptomatic patients were evaluated and confirmed for VTE by Colour Doppler Sonography. The plasma D-dimer levels were correlated statistically with the sonographic VTE. <b>Results:</b> 11 patients developed Deep Vein Thrombosis (DVT) and 1 patient developed Pulmonary embolism (PE). Preoperative plasma D-dimer levels were significantly higher</span><span "=""> </span>(P < 0.01) in patients who developed DVT postoperatively. Colour Doppler Sonography showed that 2 thrombi were seen in proximal veins<span "=""> </span><span "="">(pelvic and femoral veins), and 2 thrombi were seen in distal veins (posterior tibial, peroneal, gastrocnemian veins) of the calf in THA patients, and all 8 thrombi were seen in the distal veins (posterior tibial, peroneal, gastrocnemian veins) of the calf in TKA patients. <b>Conclusion:</b> We infer that if the preoperative D-dimer levels were more than 0.5</span><span "=""> </span>mg/l, the chances of developing VTE postoperatively are more, which can be diagnosed clinically and further by other investigations. In this study, we have shown that doing preoperative D-dimer level can almost PREDICT the development of VTE and thus prevent complications. 展开更多
关键词 Plasma d-dimer DVT Colour Doppler Clinical DVT Preoperative d-dimer TKA THA Early DVT
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Correlation Analysis Between Changes of D-Dimer Level and Rheumatoid Arthritis Complicated with Interstitial Lung Disease
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作者 Ying Li 《Journal of Clinical and Nursing Research》 2024年第6期393-397,共5页
Objective:To explore the correlation between the change of D-dimer level and rheumatoid arthritis complicated with interstitial lung disease.Methods:From January 2022 to February 2024,20 rheumatoid arthritis patients ... Objective:To explore the correlation between the change of D-dimer level and rheumatoid arthritis complicated with interstitial lung disease.Methods:From January 2022 to February 2024,20 rheumatoid arthritis patients complicated with interstitial lung disease(interstitial lung disease group),20 rheumatoid arthritis patients without interstitial lung disease(without interstitial lung disease group),and 20 healthy people(control group)in Xijing Hospital were selected for this study.The fasting venous blood of the three groups of subjects was collected and their D-dimer,C-reactive protein(CRP),rheumatoid factor(RF),and erythrocyte sedimentation rate(ESR)were detected.Subsequently,the correlation between each index and rheumatoid arthritis complicated with interstitial lung disease was analyzed.Results:The D-dimer level of the interstitial lung disease group was significantly higher than the other two groups(P<0.05).The D-dimer level of the group without interstitial lung disease was significantly higher than the control group(P<0.05).CRP levels in the interstitial lung disease group and the group without interstitial lung disease were significantly higher than those of the control group(P<0.05).The ESR and RF levels of the interstitial lung disease group were significantly higher than the other two groups(P<0.05).The levels of ESR and RF levels of the group without interstitial lung disease were significantly higher than the control group(P<0.05).Conclusion:D-dimer levels of rheumatoid arthritis patients are higher than those of healthy individuals,and those complicated with interstitial lung disease present even higher levels.This finding shows that there is a correlation between D-dimer levels and rheumatoid arthritis with interstitial lung disease,which may facilitate the evaluation and diagnosis of this disease. 展开更多
关键词 d-dimer Rheumatoid arthritis complicated with interstitial lung disease ESR Rheumatoid factor Correlation analysis
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Association between serum 25(OH)D levels and cancer in adults with psoriasis:A cross-sectional study 被引量:1
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作者 Lingquan Deng Yamei Gao +1 位作者 Chenxingyue Zhang Zhiqiang Yin 《Journal of Biomedical Research》 2026年第2期224-226,共3页
Dear Editor,Psoriasis,a chronic inflammatory cutaneous condition,is characterized by the development of red plaques with silvery scales,significantly affecting patients'quality of life and mental health[1].This co... Dear Editor,Psoriasis,a chronic inflammatory cutaneous condition,is characterized by the development of red plaques with silvery scales,significantly affecting patients'quality of life and mental health[1].This condition is thought to affect approximately 2%of the Western population,with diagnosis peaking in early adulthood[2].Vitamin D,a fat-soluble vitamin,is essential for phospho-calcium metabolism,calcium homeostasis,and bone health. 展开更多
关键词 serum oh d levels CANCER cross sectional study inflammatory cutaneous conditionis PSORIASIS ADULTS
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英国A Level考试制度的演进脉络及其对我国高考改革的镜鉴
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作者 温军英 《宁波大学学报(教育科学版)》 2026年第1期122-132,共11页
A Level考试素有“英国高考”之称。其制度演进大致经历了发轫与探索、扩张与调适、回归与重塑三个阶段,其主要变革内容包括四个方面:组织形式从年终末考的线性考试模式发展为一年多考的模块化考试,再回归线性考试模式;考试评价从常模... A Level考试素有“英国高考”之称。其制度演进大致经历了发轫与探索、扩张与调适、回归与重塑三个阶段,其主要变革内容包括四个方面:组织形式从年终末考的线性考试模式发展为一年多考的模块化考试,再回归线性考试模式;考试评价从常模参照转变为标准参照,评价手段逐步优化;考试要求从注重学科深度转变为强调知识广度,再发展为追求广度和深度并重;考试内容从偏重学术性转变为普职并重,再发展为职普融通和强调基础学科。变革的动因既有来自外部的国际竞争加剧和国内政党轮替,也有来自内部的文化价值观驱动和考试选才效度追求。A Level考试制度对我国高考改革有一定启发,我国可结合国情,以基础学科为支点、职普融通为路径、多样化的考试选择为依托、预测效度为导向,开展本土化探索。 展开更多
关键词 A level 高考 考试 选科 高校招生
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Sea level rise in the Baltic Sea:Data from Estonian coastal tide gauges over 30 years
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作者 Ivar Kapsi Tarmo Kall Aive Liibusk 《Geodesy and Geodynamics》 2026年第2期267-279,共13页
This study investigates the rate of sea level rise along the Estonian coastline of the Baltic Sea over the three decades(1993-2022)using tide gauge data and advanced analytical methods.Tide gauge data were analyzed us... This study investigates the rate of sea level rise along the Estonian coastline of the Baltic Sea over the three decades(1993-2022)using tide gauge data and advanced analytical methods.Tide gauge data were analyzed using an open-source software based on the"TG Analysis"method developed by Kristian Breili.The results reveal significant spatial and temporal variability:the average relative sea level rise was 1.35±1.91 mm/yr over the three decades,with a notable acceleration to 9.01±8.67 mm/yr in the last decade(2013-2022).Absolute sea level rise,after correction for land uplift(NKG2016LU),averaged4.16±1.81 mm/yr.Regional differences were observed,with faster relative sea level rise in areas of slower land uplift(e.g.,P??rnu,Virtsu)and vice versa.The data and trends were further analyzed by applying advanced analytical methods(differentiation,spectral and segmented regression analysis,and sea level model validation).By differentiating the sea level rise trends along the Estonian coast,and comparing tide gauge data with data from Stockholm and Hanko,the results show a minimal velocity difference(0.65 mm/yr),confirming the reliability of the trends.Spectral analysis and segmented regression analysis identified breakpoints mainly in the early 1990s,with the transition to automated tide gauges in 2010 having no significant impact.Validation of the ESA BalticSEAL model showed good performance in western Estonia,while larger discrepancies were observed in the northern regions,which are linked to local geophysical factor. 展开更多
关键词 Sea level rise Baltic Sea Tide gauge Sea level model Land uplift
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Strategies of allocating root-shoot biomass in plantations and natural forests at various community stages and moisture levels
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作者 Wenjing Chen Lei Liu +3 位作者 Josep Penuelas Guoyi Zhou Langqin Hua Zhurong Wu 《Journal of Forestry Research》 2026年第2期85-99,共15页
The root-to-shoot(R/S)ratio is a critical indicator of the balance between root biomass and shoot biomass,representing the ecological strategies and adaptive responses of plants to environmental conditions.However,the... The root-to-shoot(R/S)ratio is a critical indicator of the balance between root biomass and shoot biomass,representing the ecological strategies and adaptive responses of plants to environmental conditions.However,the patterns of change in community R/S ratios during forest succession and their response to moisture levels across broad geographic gradients remains unclear.Based on forest biomass data from a national field inventory of 5,825 plots conducted across China between 2011 and 2015,this study looked into allocating biomass shoots and roots at the early,middle,and late stages of growth in plantations and succession in natural forests,and evaluated how moisture availability influences this allocation.The results revealed a significant decline in R/S ratios from early to late stages for both plantations and natural forests.Shoot and root biomass in plantations grew isometrically during the early and middle succession stages but shifted to allometric growth in the late stage,with the slope of the log-transformed shoot-root biomass relationship differing significantly across growth stages.Natural forests,in contrast,maintained isometric growth across successional stages,showing no significant variation in the slope of the log-transformed shoot-root biomass relationship.Environmental factors,particularly moisture levels,strongly influenced R/S ratios.Moisture levels significantly affected size-corrected R/S ratios,particularly in the middle stage of plantations and the early and middle stages of natural forests,supporting the hypothesis of optimal allocation.These findings suggest that in water-limited regions,forest management should prioritize drought-tolerant,deep-rooted native species,encourage mixed-species planting in the early stage,and reduce logging intensity in mature plantations.Conserving natural forests to maintain successional dynamics is essential for long-term ecological resilience.These findings emphasize the importance of balancing productivity with ecological sustainability by adapting practices to specific environments and forest types under climate change. 展开更多
关键词 Root-to-shoot ratios Biomass allocation Forest type Community stage Moisture levels Allometric scaling
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Improved expert system of rockburst intensity level prediction based on machine learning and data-driven:Supported by 1114 rockburst cases in 197 rock underground projects
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作者 PANG Hong-li GONG Feng-qiang +1 位作者 GAO Ming-zhong DAI Jin-hao 《Journal of Central South University》 2026年第1期335-356,共22页
Accurate prediction of rockburst intensity levels is crucial for ensuring the safety of deep hard rock engineering construction.This paper introduced an expert system for rockburst intensity level prediction that empl... Accurate prediction of rockburst intensity levels is crucial for ensuring the safety of deep hard rock engineering construction.This paper introduced an expert system for rockburst intensity level prediction that employs machine learning algorithms as the basis for its inference rules.The system comprises four modules:a database,a repository,an inference engine,and an interpreter.A database containing 1114 rockburst cases was used to construct 357 datasets that serve as the repository for the expert system.Additionally,19 types of machine learning algorithms were used to establish 6783 micro-models to construct cognitive rules within the inference engine.By integrating probability theory and marginal analysis,a fuzzy scoring method based on the SoftMax function was developed and applied to the interpreter for rockburst intensity level prediction,effectively restoring the continuity of rockburst characteristics.The research results indicate that ensemble algorithms based on decision trees are more effective in capturing the characteristics of rockburst.Key factors for accurate prediction of rockburst intensity include uniaxial compressive strength,elastic energy index,the maximum principal stress,tangential stress,and their composite indicators.The accuracy of the proposed rockburst intensity level prediction expert system was verified using 20 engineering rockburst cases,with predictions aligning closely with the actual rockburst intensity levels. 展开更多
关键词 rock mechanics ROCKBURST rockburst intensity level prediction expert system machine learning supervised learning
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A Level物理教材内容及试题分析——以“天文宇宙学”为例
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作者 孟庆楠 《中学物理教学参考》 2026年第9期57-59,共3页
基于核心素养分析英国高中A Level物理教材中的天体宇宙学内容,剖析该部分内容的教学目标,以2023年6月考季第10题为例,探讨其试题命制的特点,通过对教材内容的梳理和试题的深入分析,为中学物理教学及试题多样化提供参考。
关键词 核心素养 A level物理教材 天体物理 试题命制
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The characteristics of cerebral cortical oxygenation levels and functional connectivity under upper and lower limb exercise-induced fatigue
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作者 Feng Li Yajie Wang +3 位作者 Xinyi Wang Jiawei Bi Ye Luo Lingyan Huang 《Sports Medicine and Health Science》 2026年第1期61-69,共9页
This study aims to explore the impact of fatigue induced by different limb exercises on cerebral cortical oxygenation levels and functional connectivity strength using functional near-infrared spectroscopy(fNIRS).Fati... This study aims to explore the impact of fatigue induced by different limb exercises on cerebral cortical oxygenation levels and functional connectivity strength using functional near-infrared spectroscopy(fNIRS).Fatigue was induced using an upper limb ergometer or a lower limb ergometer,with the load increasing gradually each minute.fNIRS covering the prefrontal cortex and motor cortex were used to collect data during the resting state,both before and after fatigue induction.A two-way ANOVA was conducted to examine differences in oxyhemoglobin(HbO_(2))and functional connectivity before and after fatigue induction in both groups,with the significance level set at 0.05.Exercise-induced fatigue in both the upper and lower limbs leads to a significant decrease in cerebral cortical oxygenation levels.Upper limb fatigue leads to a significant reduction in functional connectivity,there were significant decreases in connectivity within the motor cortex,between the motor cortex and frontal regions,and between the right ventrolateral prefrontal cortex and other frontal regions.Conversely,no significant changes were observed before and after lower limb fatigue.Future studies should focus on examining the extent to which how changes in the cerebral cortex,induced by exercise fatigue,are linked to exercise-and/or performance-related outcomes. 展开更多
关键词 Brain functional connectivity Cerebral oxygenation level Exercise-induced fatigue Functional near-infrared spectroscopy
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An unsupervised deep learning-based online anomaly detection model for mold level in continuous casting process
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作者 Meng-Ying Geng Zheng-Yi Li +3 位作者 Yu-Han Xu Shuang-Li Liu Yi-Bo Ai Wei-Dong Zhang 《Journal of Iron and Steel Research International》 2026年第2期318-331,共14页
Maintaining constant mold level variations during the continuous casting process is essential to guarantee the effectiveness and quality of steel production. An unsupervised deep learning-based mold level anomaly dete... Maintaining constant mold level variations during the continuous casting process is essential to guarantee the effectiveness and quality of steel production. An unsupervised deep learning-based mold level anomaly detection (MLAD) model for real-time monitoring of mold level fluctuations under varying operating conditions was proposed. The MLAD framework employs a two-stage encoder-decoder structure with adversarial training to accurately reconstruct time-series mold level data. In the first stage, the model learns long-term trends by reconstructing input windows, while in the second stage, it employs reconstruction errors as focus scores to capture short-term anomaly patterns. A transformer-based architecture, incorporating multi-head attention mechanisms and positional encoding, enables MLAD to capture both local and global temporal dependencies. In addition, a novel multi-threshold strategy, based on extreme value theory, is implemented to enhance the model’s ability and to adapt to varying operating conditions, including startup, steady-state, and shutdown phases. The model was validated with over 240-h real data from a steel factory. The results demonstrate its superior performance in anomaly detection compared to popular methods, with a precision of 0.9937, recall of 0.9932, and a low false alarm rate of 0.0038. MLAD represents a significant advancement in the detection of nonlinear and nonstationary anomalies in industrial processes, offering an efficient solution for smart manufacturing systems. Therefore, the established model could be used for online anomaly detection of mold level with real-time data. 展开更多
关键词 Continuous casting Unsupervised learning Time series Anomaly detection Mold level abnormal fluctuation
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Suitable area selection method based on scene matching level segmentation
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作者 Chao YANG Yuanxin YE +3 位作者 Renyuan LIU Chengjia FAN Liang ZHOU Jiwei DENG 《Chinese Journal of Aeronautics》 2026年第2期356-369,共14页
The selection of a suitable navigation area is pivotal in aircraft scene matching guidance technology.This study addresses the challenge of identifying suitable reference image ranges for precise scene matching,which ... The selection of a suitable navigation area is pivotal in aircraft scene matching guidance technology.This study addresses the challenge of identifying suitable reference image ranges for precise scene matching,which is crucial for enhancing aircraft positioning accuracy.Traditional methods for image matchability analysis are often limited by their reliance on manual feature parameter design and threshold-based filtering,resulting in suboptimal accuracy and efficiency.This paper proposes a novel network architecture for selecting suitable navigation areas using image Matching Level Segmentation(MLSNet).The approach involves two key innovations:a method for generating segmentation labels that quantify matchability levels and an end-to-end network architecture for rapid and precise prediction of reference image matchability segmentation maps.The network includes two core modules:the saliency analysis module uses multi-layer convolutional networks to accurately detect image saliency features across various levels and scales;the multidimensional attention module utilizes attention mechanisms to focus on feature channels and spatial neighborhood scenes to assess the image’s matchability.Our method was rigorously tested on an extensive collection of remote sensing images,where it was benchmarked against a range of both traditional and cutting-edge deep learning methods.The findings indicate that MLSNet is significantly superior to traditional methods in accuracy and efficiency of matchability analysis,and is also relatively ahead of state-of-the-art deep learning models. 展开更多
关键词 Deep learning Image matching level segmentation OPTICAL Scene matching navigation Suitable matching area selection
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Homeostasis and failure of mitochondria on the single-cell level
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作者 Kristina Friedland Kristina Endres 《Neural Regeneration Research》 2026年第8期3555-3556,共2页
Mitochondria are the central organelles that allow eukaryotic cells to efficiently convert nutrients into energy for cellular functions such as anabolic reactions,movement,and regulation.A reduction in the number of m... Mitochondria are the central organelles that allow eukaryotic cells to efficiently convert nutrients into energy for cellular functions such as anabolic reactions,movement,and regulation.A reduction in the number of mitochondria or the occurrence of dysfunctional mitochondria leads to serious diseases such as the Leigh syndrome.However,such changes have also been connected to Alzheimer’s disease(AD)and many more diseases of different organ systems and occur during the aging process.Mitochondria are,therefore. 展开更多
关键词 eukaryotic cells HOMEOSTASIS convert nutrients energy organ systems MITOCHONDRIA central organelles anabolic reactionsmovementand single cell level
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