320 research outputs found
MD-Manifold: A Medical Distance Based Manifold Learning Approach for Heart Failure Readmission Prediction
Dimension reduction is considered as a necessary technique in Electronic Healthcare Records (EHR) data processing. However, no existing work addresses both of the two points: 1) generating low-dimensional representations for each patient visit; and 2) taking advantage of the well-organized medical concept structure as the domain knowledge. Hence, we propose a new framework to generate low-dimensional representations for medical data records by combining the concept-structure based distance with manifold learning. To demonstrate the efficacy, we generated low-dimensional representations for hospital visits of heart failure patients, which was further used for a 30-day readmission prediction. The experiments showed a great potential of the proposed representations (AUC = 60.7%) that has comparative predictive power of the state-of-the-art methods, including one hot encoding representations (AUC = 60.1%) and PCA representations (AUC = 58.3%), with much less training time (improved by 99%). The proposed framework can also be generalized to various healthcare-related prediction tasks, such as mortality prediction
ICU Outcome Predictions Using Real-Time Signals with Wavelet-Transform-based Convolutional Neural Network
Intensive care units (ICUs) serve patients with life-threatening conditions. The limited ICU resources cause severe economic and healthcare burdens worldwide. It is critical to conduct ICU outcome predictions at an early stage and promote efficient use of ICU resources. However, all the current prediction methods have limitations such as unsatisfactory accuracy and depending on resource-demanding laboratory tests or expert domain knowledge. In this research, we design a wavelet-transformed-based convolutional neural network, WTCNN, which only requires patients’ vital sign series and information at ICU admission for real-time ICU outcome predictions. The model is evaluated using a large real-world ICU database and outperforms state-of-art baselines on both ICU mortality and length-of-stay prediction tasks. We conduct LIME for model interpretation and prescriptive analysis. Our work provides an efficient tool for ICU outcome predictions, allowing healthcare providers to take action promptly on patients at risk and reduce the negative impacts on patient outcomes
Multi-views Fusion CNN for Left Ventricular Volumes Estimation on Cardiac MR Images
Left ventricular (LV) volumes estimation is a critical procedure for cardiac
disease diagnosis. The objective of this paper is to address direct LV volumes
prediction task. Methods: In this paper, we propose a direct volumes prediction
method based on the end-to-end deep convolutional neural networks (CNN). We
study the end-to-end LV volumes prediction method in items of the data
preprocessing, networks structure, and multi-views fusion strategy. The main
contributions of this paper are the following aspects. First, we propose a new
data preprocessing method on cardiac magnetic resonance (CMR). Second, we
propose a new networks structure for end-to-end LV volumes estimation. Third,
we explore the representational capacity of different slices, and propose a
fusion strategy to improve the prediction accuracy. Results: The evaluation
results show that the proposed method outperforms other state-of-the-art LV
volumes estimation methods on the open accessible benchmark datasets. The
clinical indexes derived from the predicted volumes agree well with the ground
truth (EDV: R2=0.974, RMSE=9.6ml; ESV: R2=0.976, RMSE=7.1ml; EF: R2=0.828, RMSE
=4.71%). Conclusion: Experimental results prove that the proposed method may be
useful for LV volumes prediction task. Significance: The proposed method not
only has application potential for cardiac diseases screening for large-scale
CMR data, but also can be extended to other medical image research fieldsComment: to appear on Transactions on Biomedical Engineerin
Research of influence and mechanism of combining exercise with diet control on a model of lipid metabolism rat induced by high fat diet
OBJECTIVE: To investigate the influence and mechanism of combining exercise with diet control on a model of lipid metabolism rat induced by high fat diet. METHODS: Twenty-four male Wistar rats were randomly divided into 3 groups of 8: normal, model and intervention. The model group and intervention group were fed with high fat diet, while the normal group received basal feed. From day 1, the intervention group was randomly given interventions such as swimming exercise and dietary restriction. The interventions duration were 28 days. At the end of the experiment, the levels of rats’ body weight and liver weight were detected, the serum levels of total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) and hepatic triglyceride content (TG) were detected by using biochemical assay, serum level of gastrin (GAS), motilin (MTL) were assayed by the enzyme linked immunosorbent assay (ELISA). RESULTS: Compared with the level of body weight and liver weight in the normal rats, body weight and liver weight in the rat of the model group were significantly increase (P<0.05 or P<0.01). Plasma concentrations of TC, LDL-C and hepatic TG in the model group were significantly increased compared with those in the normal group (P<0.05 or P<0.01). The contents of GAS, MTL, HDL-C in the model rats’plasma were significantly reduced compared with those of the normal group (P<0.05 or P<0.01). Compared with those in the model group, rats’ body weight, liver weight, serum TC, LDL-C, and TG content of liver in the intervention group decreased significantly (P<0.05 or P<0.01). Meanwhile, serum content of GAS, MTL, HDL-C were significantly improved in the intervention rats compared to the model group. CONCLUSION: The action of combining exercise with diet control for lipid metabolism disorder might be related to regulation of GAS, MTL and other gastrointestinal hormones
A Quasi-27-Day Oscillation Activity From the Troposphere to the Mesosphere And Lower Thermosphere at Low Latitudes
Using meteor radar, radiosonde observations and MERRA-2 reanalysis data from 12 August to 31 October 2006, we report a dynamical coupling from the tropical lower atmosphere to the mesosphere and lower thermosphere through a quasi-27-day intraseasonal oscillation (ISO). It is interesting that the quasi-27-day ISO is observed in the troposphere, stratopause and mesopause regions, exhibiting a three-layer structure. In the MLT, the amplitude in the zonal wind increases from about 4 ms−1 at 90 km to 15 ms−1 at 100 km, which is diferent from previous observations that ISOs occurs generally in winter with an amplitude peak at about 80–90 km, and then are rapidly weakened with increasing height. Outgoing longwave radiation (OLR) and specifc humidity demonstrate that there is a quasi-27-day periodicity in convective activity in the tropics, which causes the ISO of the zonal wind and gravity wave (GW) activity in the troposphere. The upward propagating GWs are further modulated by the oscillation in the troposphere and upper stratosphere. As the GWs propagate to the MLT, the quasi-27-day oscillation in the wind feld is induced with a clear phase opposite to that in the lower atmosphere through instability and dissipation of these modulated GWs. Wavelet analysis shows that the quasi-27-day variability in the MLT appears as a case event rather than a persistent phenomenon, and has not a clear corresponding relation with the solar rotation efect within 1 year of observations
{\pi}-{\pi} Interaction-facilitated formation of interwoven trimeric cage-catenanes with topological chirality
Catenanes as interlocked molecules with a nonplanar graph have gained
increasing attention for their unique features such as topological chirality.
To date, the majority of research in this field has been focusing on catenanes
comprising monocyclic rings. Due to the lack of rational synthetic strategy,
catenanes of cage-like monomers are hardly accessible. Here we report on the
construction of an interwoven trimeric catenane that is composed of achiral
organic cages, which exhibits topological chirality. Our rational design begins
with a pure mathematical analysis, revealing that the formation probability of
the interwoven trimeric catenane surpasses that of its chain-like analogue by
20%; while driven by efficient template effect provided by strong {\pi}-{\pi}
stacking of aromatic panels, the interwoven structure emerges as the dominant
species, almost ruling out the formation of the chain-like isomer. Its
topological chirality is unambiguously unravelled by chiral-HPLC, CD
spectroscopy and X-ray diffraction. Our probability analysis-aided rational
design strategy would pave a new venue for the efficient synthesis of
topologically sophisticated structures in one pot
カイカク カイホウキ チュウゴク ニ オケル リュウガクセイ セイサク ノ ヘンヨウ トウ ショウヘイ ノ ヤクワリ ヲ チュウシン ニ
Synthesizing heretofore available Chinese sources, this article re-examines the transformation of China’s Study-Abroad Program (SAP) from 1977 to 1996, a transitional period of SAP from infancy to maturity. It explores the process by which Deng Xiaoping, de facto leader of the PRC from 1978-1990, rescued education out of chaos in the early stage of Reform and Opening (R&O) and the dynamics between the political movements launched by him and the restrictions of SAP in the 1980s. During this period, with the development of R&O, China's ties with the outside world became increasingly close, which prompted Deng to rethink how China should send SAP students in the late 1980s, particularly after the Anti-Bourgeois Liberalization Campaign in 1987 and the Tiananmen Incident in 1989, when many Chinese students changed their status to remain in the US. In the end, Deng found a relatively mature and open solution—encouraging students to return home instead of restricting their departure—which marked the beginning of SAP's maturity. This article concludes that despite the predominant scholarly focus on the result of the SAP transformation, the motivator for this change was Deng, who facilitated the implementation and maturity of SAP in the critical period of reform. Simultaneously, however, he was affected by the domestic politics, which resulted in SAP’s fluctuations.投稿論文Refereed Articl
Coupling Evidence From Lower Atmosphere to Mesosphere and Ionosphere Through Quasi 27-Day Oscillation
Using meteor radar, radiosonde and digisonde observations and MERRA-2 reanalysis data from 12 August to 31 October 2006, we report a dynamical coupling from the tropical lower atmosphere to the mesosphere and ionospheric F2 region through a quasi 27-day intraseasonal oscillation (ISO). It is interesting that the quasi 27-day ISO is active in the troposphere and stratopause and mesopause regions, exhibiting a three-layer structure. In the mesosphere and lower thermosphere (MLT), the amplitude in the zonal wind increases from about 4 ms at 90 km to 15 ms at 100 km, which is different from previous observations that ISOs generally have the amplitude peak at about 80-85 km, and then weakens with height. OLR and specific humidity data demonstrate that there is a quasi 27-day periodicity in convective activity in the tropics, which causes the ISO of the zonal wind and gravity wave (GW) activity in the troposphere. GW energy in the stratosphere also exhibits a sharp spectral speak at 27-day period, meaning that the convectively modulated GWs play a vital role in driving the oscillation in the MLT. The quasi 27-day variability arises clearly in the hmF2. Wavelet analysis shows that the dominant period and active time of the hmF2 oscillation are in good agreement with those in the zonal wind of the MLT and OLR rather than in the F10.7 and Kp index. Hence, tropical convective activity has an influence on the dynamics of the MLT and F2 region through modulated waves and ISOs
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