1,151 research outputs found
Prediction of wave force on netting under strong nonlinear wave action
Under the strong nonlinear wave environment, accurate simulation of wave force for aquaculture netting is an effective guarantee for cage design and safety. In this paper, the horizontal wave forces of a nylon square-mesh netting panel were obtained through a series of strong nonlinear regular wave tests, and their nonlinearity was analyzed by amplitude spectrum. Moreover, the Morison equation based on fifth-order Stokes wave theory was used to reasonably predict the wave force on the netting. The results showed that both wave and wave force have strong nonlinearity, especially the latter. The frequency domain characteristics of the test wave and wave force are similar, while the higher frequency components of the test force are more apparent. The predicted wave forces are in good agreement with the test values in time and frequency domain, and zero or higher frequency components of predicted force are more prominent with the increase of wave steepness. When the range of the Keulegan-Carpenter number is 35-120, the average drag and inertia coefficient of the predicted force are 2.4 and 2.1, respectively. The results can provide a more accurate assessment of the nonlinear wave force on aquaculture facilities
The gastrointestinal-brain-microbiota axis: a promising therapeutic target for ischemic stroke
Ischemic stroke is a highly complex systemic disease characterized by intricate interactions between the brain and gastrointestinal tract. While our current understanding of these interactions primarily stems from experimental models, their relevance to human stroke outcomes is of considerable interest. After stroke, bidirectional communication between the brain and gastrointestinal tract initiates changes in the gastrointestinal microenvironment. These changes involve the activation of gastrointestinal immunity, disruption of the gastrointestinal barrier, and alterations in gastrointestinal microbiota. Importantly, experimental evidence suggests that these alterations facilitate the migration of gastrointestinal immune cells and cytokines across the damaged blood-brain barrier, ultimately infiltrating the ischemic brain. Although the characterization of these phenomena in humans is still limited, recognizing the significance of the brain-gastrointestinal crosstalk after stroke offers potential avenues for therapeutic intervention. By targeting the mutually reinforcing processes between the brain and gastrointestinal tract, it may be possible to improve the prognosis of ischemic stroke. Further investigation is warranted to elucidate the clinical relevance and translational potential of these findings
Benchmarking of eight recurrent neural network variants for breath phase and adventitious sound detection on a self-developed open-access lung sound database-HF_Lung_V1
A reliable, remote, and continuous real-time respiratory sound monitor with
automated respiratory sound analysis ability is urgently required in many
clinical scenarios-such as in monitoring disease progression of coronavirus
disease 2019-to replace conventional auscultation with a handheld stethoscope.
However, a robust computerized respiratory sound analysis algorithm has not yet
been validated in practical applications. In this study, we developed a lung
sound database (HF_Lung_V1) comprising 9,765 audio files of lung sounds
(duration of 15 s each), 34,095 inhalation labels, 18,349 exhalation labels,
13,883 continuous adventitious sound (CAS) labels (comprising 8,457 wheeze
labels, 686 stridor labels, and 4,740 rhonchi labels), and 15,606 discontinuous
adventitious sound labels (all crackles). We conducted benchmark tests for long
short-term memory (LSTM), gated recurrent unit (GRU), bidirectional LSTM
(BiLSTM), bidirectional GRU (BiGRU), convolutional neural network (CNN)-LSTM,
CNN-GRU, CNN-BiLSTM, and CNN-BiGRU models for breath phase detection and
adventitious sound detection. We also conducted a performance comparison
between the LSTM-based and GRU-based models, between unidirectional and
bidirectional models, and between models with and without a CNN. The results
revealed that these models exhibited adequate performance in lung sound
analysis. The GRU-based models outperformed, in terms of F1 scores and areas
under the receiver operating characteristic curves, the LSTM-based models in
most of the defined tasks. Furthermore, all bidirectional models outperformed
their unidirectional counterparts. Finally, the addition of a CNN improved the
accuracy of lung sound analysis, especially in the CAS detection tasks.Comment: 48 pages, 8 figures. To be submitte
Grain size-dependent magnetic and electric properties in nanosized YMnO3 multiferroic ceramics
Magnetic and electric properties are investigated for the nanosized YMnO3 samples with different grain sizes (25 nm to 200 nm) synthesized by a modified Pechini method. It shows that magnetic and electric properties are strongly dependent on the grain size. The magnetic characterization indicates that with increasing grain size, the antiferromagnetic (AFM) transition temperature increases from 52 to 74 K. A corresponding shift of the dielectric anomaly is observed, indicating a strong correlation between the electric polarization and the magnetic ordering. Further analysis suggests that the rising of AFM transition temperature with increasing grain size should be from the structural origin, in which the strength of AFM interaction as well as the electrical polarization is dependent on the in-plane lattice parameters. Furthermore, among all samples, the sample with grain size of 95 nm is found to have the smallest leakage current density (< 1 ÎŒA/cm2)
Chemical constituents from Chirita longgangensis var. hongyao with inhibitory activity against porcine respiratory and reproductive syndrome virus
Climate Variability and Hemorrhagic Fever with Renal Syndrome Transmission in Northeastern China
Background: The transmission of hemorrhagic fever with renal syndrome (HFRS) is influenced by climatic variables. However, few studies have examined the quantitative relationship between climate variation and HFRS transmission. ---------- Objective: We examined the potential impact of climate variability on HFRS transmission and developed climate-based forecasting models for HFRS in northeastern China. ---------- Methods: We obtained data on monthly counts of reported HFRS cases in Elunchun and Molidawahaner counties for 1997â2007 from the Inner Mongolia Center for Disease Control and Prevention and climate data from the Chinese Bureau of Meteorology. Cross-correlations assessed crude associations between climate variables, including rainfall, land surface temperature (LST), relative humidity (RH), and the multivariate El Niño Southern Oscillation (ENSO) index (MEI) and monthly HFRS cases over a range of lags. We used time-series Poisson regression models to examine the independent contribution of climatic variables to HFRS transmission. ----------- Results: Cross-correlation analyses showed that rainfall, LST, RH, and MEI were significantly associated with monthly HFRS cases with lags of 3â5 months in both study areas. The results of Poisson regression indicated that after controlling for the autocorrelation, seasonality, and long-term trend, rainfall, LST, RH, and MEI with lags of 3â5 months were associated with HFRS in both study areas. The final model had good accuracy in forecasting the occurrence of HFRS. ---------- Conclusions: Climate variability plays a significant role in HFRS transmission in northeastern China. The model developed in this study has implications for HFRS control and prevention
Thrombomodulin Regulates Keratinocyte Differentiation and Promotes Wound Healing
The membrane glycoprotein thrombomodulin (TM) has been implicated in keratinocyte differentiation and wound healing, but its specific function remains undetermined. The epidermis-specific TM knockout mice were generated to investigate the function of TM in these biological processes. Primary cultured keratinocytes obtained from TMlox/lox; K5-Cre mice, in which TM expression was abrogated, underwent abnormal differentiation in response to calcium induction. Poor epidermal differentiation, as evidenced by downregulation of the terminal differentiation markers loricrin and filaggrin, was observed in TMlox/lox; K5-Cre mice. Silencing TM expression in human epithelial cells impaired calcium-induced extracellular signalâregulated kinase pathway activation and subsequent keratinocyte differentiation. Compared with wild-type mice, the cell spreading area and wound closure rate were lower in keratinocytes from TMlox/lox; K5-Cre mice. In addition, the lower density of neovascularization and smaller area of hyperproliferative epithelium contributed to slower wound healing in TMlox/lox; K5-Cre mice than in wild-type mice. Local administration of recombinant TM (rTM) accelerated healing rates in the TM-null skin. These data suggest that TM has a critical role in skin differentiation and wound healing. Furthermore, rTM may hold therapeutic potential for the treatment of nonhealing chronic wounds
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