88 research outputs found
Apical conicity ratio: A new index on left ventricular apical geometry after myocardial infarction
ObjectiveOur objective was to introduce a new index to evaluate left ventricular aneurysm by quantitative analysis of left ventricular apical geometry.MethodsA total of 116 selected subjects underwent magnetic resonance imaging, 28 healthy volunteers, 29 patients with dilated cardiomyopathy, and 59 patients with ischemic heart disease (26 with left ventricular aneurysm; 33 with no aneurysm). The apical conicity ratio was calculated as the ratio of left ventricular apical area over apical triangle.ResultsDiastolic apical conicity ratio of patients with left ventricular aneurysm was 1.62 ± 0.20 and systolic apical conicity ratio was 1.78 ± 0.43. After left ventricular reconstruction, the diastolic apical conicity ratio decreased to 1.47 ± 0.23 and the systolic ratio to 1.51 ± 0.21, which came close to the normal level, whereas other global indices remained. In patients with dilated cardiomyopathy, sphericity index and eccentricity index increased significantly without changes in the apical conicity ratio. Among patients with ischemic heart disease, the apical conicity ratio of the group with left ventricular aneurysm was significantly higher than that of the group without an aneurysm when the other indices between the 2 groups showed no statistically difference. Receiver operating characteristic curves showed only apical conicity ratio had high power of discriminating left ventricular aneurysm from no aneurysm.ConclusionsThe new index, apical conicity ratio, can be used to quantify the regional left ventricular deformation, especially in patients with left ventricular aneurysm resulting from myocardial infarction
The variation changes of the precipitation – runoff relationship
The variation of the rainfall-runoff relationship t will lead to the disappearance of the consistency assumption of engineering hydrology, which will influence the planning, design, operation management and development and utilization of water resources. Therefore, the variation diagnosis of the rainfall -runoff relationship has become one of the hot topics and key issues in this area. In this study, the variation points of the precipitation-runoff relationship are defined, the difference between the variation point and the mutation point is distinguished, and the method of variation classification is proposed based on the the dimensionless mean and variation coefficients. Then, a comprehensive diagnosis system of the rainfall-runoff relationship variation is constructed on the basis of systematically summarying and analyzing of the diagnosis method of rainfall - runoff relationship variation at home and abroad. Taking the Weihe River Basin as a case study, the comprehensive diagnosis system is verified by applying it to test the change point the annual runoff time series at the Huaxian hydrological station. And the results show that the comprehensive diagnosis method proposed in this paper is scientific and reasonable
Ly Leaks and Reionization
Ly absorption spectra of QSOs at redshifts show complete
Gunn-Peterson absorption troughs (dark gaps) separated by tiny leaks. The dark
gaps are from the intergalactic medium (IGM) where the density of neutral
hydrogen are high enough to produce almost saturated absorptions, however,
where the transmitted leaks come from is still unclear so far. We demonstrate
that leaking can originate from the lowest density voids in the IGM as well as
the ionized patches around ionizing sources using semi-analytical simulations.
If leaks were produced in lowest density voids, the IGM might already be highly
ionized, and the ionizing background should be almost uniform; in contrast, if
leaks come from ionized patches, the neutral fraction of IGM would be still
high, and the ionizing background is significantly inhomogeneous. Therefore,
the origin of leaking is crucial to determining the epoch of
inhomogeneous-to-uniform transition of the the ionizing photon background. We
show that the origin could be studied with the statistical features of leaks.
Actually, Ly leaks can be well defined and described by the equivalent
width and the full width of half area , both of which are less
contaminated by instrumental resolution and noise. It is found that the
distribution of and of Ly leaks are sensitive to the
modeling of the ionizing background. We consider four representative
reionization models. It is concluded that the leak statistics provides an
effective tool to probe the evolutionary history of reionization at
. Similar statistics would also be applicable to the reionization
of He II at (Abridged)Comment: 11 pages including 10 figures, accepted for publication in MNRA
Correlation analysis between 18F-fluorodeoxyglucose positron emission tomography and cognitive function in first diagnosed Parkinson’s disease patients
ObjectiveEvaluation of the correlation between 18F-fluorodeoxyglucose-positron emission tomography (18F-FDG PET) and cognitive function in first-diagnosed and untreated Parkinson’s disease (PD) patients.Materials and methodThis cross-sectional study included 84 first diagnosed and untreated PD patients. The individuals were diagnosed by movement disorder experts based on the 2015 MDS Parkinson’s disease diagnostic criteria. The patients also underwent 18F-FDG PET scans and clinical feature assessments including the Montreal Cognitive Assessment (MoCA) scale. Glucose metabolism rates were measured in 26 brain regions using region of interest (ROI) and pixel-wise analyses with displayed Z scores. The cognitive function was assessed by professionals using the MoCA scale, which covers five cognitive domains. Spearman’s linear correlation and linear regression models were used to compare the correlations between 18F-FDG metabolism in each brain region and cognitive domain, using SPSS 25.0 software.ResultThe results indicated a positive correlation between executive function and glucose metabolism in the lateral prefrontal cortex of the left hemisphere (p = 0.041). Additionally, a positive correlation between memory function and glucose metabolism in the right precuneus (p = 0.014), right lateral occipital cortex (p = 0.017), left lateral occipital cortex (p = 0.031), left primary visual cortex (p = 0.008), and right medial temporal cortex (p = 0.046). Further regression analysis showed that for every one-point decrease in the memory score, the glucose metabolism in the right precuneus would decrease by 0.3 (B = 0.30, p = 0.005), the glucose metabolism in the left primary visual cortex would decrease by 0.25 (B = 0.25, p = 0.040), the glucose metabolism in the right lateral occipital cortex would decrease by 0.38 (B = 0.38, p = 0.012), and the glucose metabolism in the left lateral occipital cortex would decrease by 0.32 (B = 0.32, p = 0.045).ConclusionThis study indicated that cognitive impairment in PD patients mainly manifests as changes in executive function, visual-spatial function and memory functions, while glucose metabolism mainly decreases in the frontal and posterior cortex. Further analysis shows that executive function is related to glucose metabolism in the left lateral prefrontal cortex. On the other hand, memory ability involves changes in glucose metabolism in a more extensive brain region. This suggests that cognitive function assessment can indirectly reflect the level of glucose metabolism in the relevant brain regions
Characteristics and influencing factors of 11C-CFT PET imaging in patients with early and late onset Parkinson’s disease
ObjectiveThis study aims to explore the difference between 11C-methyl-N-2β-carbomethoxy-3β-(4-fluorophenyl)-tropanel (11C-CFT) positron emission tomography (PET) imaging in the early-onset Parkinson’s disease (EOPD) and late-onset Parkinson’s disease (LOPD), and to analyze the correlation between 11C-CFT PET imaging and disease duration, Hoehn & Yahr (H&Y) stage, motor symptoms, and non-motor symptoms in patients with idiopathic Parkinson’s disease (PD), so as to explore its application value in assessing the severity of Parkinson’s disease.Materials and methodsA total of 113 patients with idiopathic PD were included in this study. The patients were divided into EOPD and LOPD groups according to the age of 60 years, of which 58 were early-onset and 55 were late-onset. All patients underwent 11C-CFT PET imaging and manually sketched regions of interest (ROI) to delineate the caudate nucleus, anterior putamen, and posterior putamen ROI layer-by-layer, and the corresponding values were recorded. Clinical data [age of onset, disease duration, H&Y stage, total Unified Parkinson’s Disease Rating Scale (UPDRS) score, UPDRS III score, tremor score, postural instability/gait difficulty (PIGD) score, rigidity score, bradykinesia score, and Montreal Cognitive Assessment (MoCA) score] were collected from all patients. The differences in striatal 11C-CFT uptake between patients with EOPD and LOPD were compared, and the correlation between striatal 11C-CFT uptake and the clinical data of patients with idiopathic PD was evaluated.ResultsThe caudate nucleus 11C-CFT uptake was higher in EOPD than in the LOPD group (t = 3.002, p = 0.003). 11C-CFT uptake in the caudate nucleus in patients with PD was negatively correlated with the age of onset, H&Y stage, disease duration, total UPDRS score, UPDRS III score, rigidity score, and bradykinesia score (p < 0.05). The anterior and posterior putamen 11C-CFT uptake was negatively correlated with H&Y stage, disease duration, total UPDRS score, UPDRS III score, PIGD score, rigidity score, and bradykinesia score (p < 0.05).Conclusion11C-CFT PET provides an objective molecular imaging basis for the difference in disease progression rates between patients with EOPD and LOPD. Secondly, 11C-CFT PET can be used as an important objective indicator to assess disease severity and monitor disease progression
Keragaman Genetik Dan Pendugaan Jumlah Gen Ketahanan Kacang Panjang (Vigna Sinensis L.) Terhadap Penyakit Kuning
Penyakit kuning pada kacang panjang berdampak pada penurunan produksi. Gejala serangan diawali dari gejala daun keriting serta mengakibatkan polong berwarna kuning. Penelitian ini bertujuan mengetahui nilai heritabilitas dan ragam genetik serta menduga jumlah gen pengendali ketahanan kacang panjang terhadap penyakit kuning. Penelitian dilaksanakan di Kabupaten Kediri pada bulan April sampai Juli 2013. Bahan penelitian adalah populasi UB 715 A (P1), Hitam Putih (P2), populasi F1 dan populasi F2. Berdasarkan hasil penelitian, populasi UB 715 A (P1 ) menunjukkan respon tahan terhadap penyakit kuning, populasi Hitam Putih (P2) menunjukkan respon rentan, dan populasi F1 dan F2 menunjukkan respon sedang. Karakter jumlah polong dan jumlah biji per tanaman memiliki keragaman yang sempit sedangkan karakter panjang polong, bobot segar polong, umur berbunga, dan umur panen memiliki keragaman yang luas. Karakter panjang polong dan jumlah biji per polong memiliki nilai heritabilitas rendah, sedangkan karakter jumlah polong, bobot segar polong, umur berbunga, dan umur panen memiliki nilai heritabilitas tinggi. Rasio sifat ketahanan terhadap penyakit kuning pada populasi F2 adalah 9 tahan : 3 sedang : 4 rentan yang berarti ketahanan terhadap penyakit kuning dikendalikan oleh dua gen dengan aksi gen epistasis resesif
Genetic analysis and fine mapping of the pubescence gene GL6 in rice (Oryza sativa L.)
Value-Added-Based Accounting of CO2 Emissions: A Multi-Regional Input-Output Approach
In the era of globalization and international trade, the production-based CO2 emissions accounting system, proposed by United Nations Framework Convention on Climate Change, can easily lead to a “carbon leakage” issue. Thus, the accounting of consumption-based carbon emissions and carbon emissions embodied in international trade has received considerable research attention. Nevertheless, researchers also indicated that the consumption-based principle has some weaknesses, for example, it leads the producers inert on reducing carbon emissions while gaining economic benefits. To share carbon emissions responsibilities between producers and consumers is widely recognized. So, setting an income-based emissions accounting method as to producer is a necessary complement for accounting national carbon emissions. This study promoted a model, called the value-added-based accounting of CO2 emissions method, to account for anthropogenic CO2 emissions within the context of the economic benefit principle. Based on the global multi-regional input-output table and national carbon emissions database, we calculated the national/regional carbon emissions based on the value-added accounting approach as well as the amount of global carbon emissions embodied in value-added chains. If the results are served as a supplement for calculating the amount of CO2 emissions reduction that a country is responsible for, problems such as carbon leakage and resistance to improving the energy efficiency of exporting sector may be solved, because all the supply chains emissions associated with the economic growth of a country would be considered
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