44 research outputs found
Hypothermia in Stroke Therapy: Systemic versus Local Application
Presently, there are no effective, widely applicable therapies for ischemic stroke. There is strong clinical evidence for the neuroprotective benefits of hypothermia, and surface-cooling methods have been utilized for decades in the treatment of cerebral ischemia during cardiac arrest, but complications with hypothermia induction have hindered its clinical acceptance in ischemic stroke therapy. Recently, the microcatheter-based local endovascular infusion (LEVI) of cold saline directly to the infarct site has been proposed as a solution to the drawbacks of surface cooling. The safety and efficacy of LEVI in rat models have been established, and implementation in larger animals has been similarly encouraging. A recent pilot study even established the safety of LEVI in humans. This review seeks to outline the major research on LEVI, discusses the mechanisms that mediate its superior neuroprotection over surface and systemic cooling, and identifies areas that warrant further investigation. While LEVI features improvements on surface cooling, its core mechanisms of neuroprotection are still largely shared with therapeutic hypothermia in general. As such, the mechanisms of hypothermia-based neuroprotection are discussed as well
DSFNet: Learning Disentangled Scenario Factorization for Multi-Scenario Route Ranking
Multi-scenario route ranking (MSRR) is crucial in many industrial mapping
systems. However, the industrial community mainly adopts interactive interfaces
to encourage users to select pre-defined scenarios, which may hinder the
downstream ranking performance. In addition, in the academic community, the
multi-scenario ranking works only come from other fields, and there are no
works specifically focusing on route data due to lacking a publicly available
MSRR dataset. Moreover, all the existing multi-scenario works still fail to
address the three specific challenges of MSRR simultaneously, i.e. explosion of
scenario number, high entanglement, and high-capacity demand. Different from
the prior, to address MSRR, our key idea is to factorize the complicated
scenario in route ranking into several disentangled factor scenario patterns.
Accordingly, we propose a novel method, Disentangled Scenario Factorization
Network (DSFNet), which flexibly composes scenario-dependent parameters based
on a high-capacity multi-factor-scenario-branch structure. Then, a novel
regularization is proposed to induce the disentanglement of factor scenarios.
Furthermore, two extra novel techniques, i.e. scenario-aware batch
normalization and scenario-aware feature filtering, are developed to improve
the network awareness of scenario representation. Additionally, to facilitate
MSRR research in the academic community, we propose MSDR, the first large-scale
publicly available annotated industrial Multi-Scenario Driving Route dataset.
Comprehensive experimental results demonstrate the superiority of our DSFNet,
which has been successfully deployed in AMap to serve the major online traffic
Association of platelet-to-lymphocyte ratio and neutrophil-to-lymphocyte ratio with outcomes in stroke patients achieving successful recanalization by endovascular thrombectomy
ObjectiveSerum inflammatory biomarkers play crucial roles in the development of acute ischemic stroke (AIS). In this study, we explored the association between inflammatory biomarkers including platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), and monocyte-to-lymphocyte ratio (MLR), and clinical outcomes in AIS patients who achieved successful recanalization.MethodsPatients with AIS who underwent endovascular thrombectomy (EVT) and achieved a modified thrombolysis in the cerebral infarction scale of 2b or 3 were screened from a prospective cohort at our institution between January 2013 and June 2021. Data on blood parameters and other baseline characteristics were collected. The functional outcome was an unfavorable outcome defined by a modified Rankin Scale of 3–6 at the 3-month follow up. Other clinical outcomes included symptomatic intracranial hemorrhage (sICH) and 3-month mortality. Multivariable logistic regression analysis was performed to evaluate the effects of PLR, NLR, and MLR on clinical outcomes.ResultsA total of 796 patients were enrolled, of which 89 (11.2%) developed sICH, 465 (58.4%) had unfavorable outcomes at 3 months, and 168 (12.1%) died at the 3-month follow up. After adjusting for confounding variables, a higher NLR (OR, 1.076; 95% confidence interval [CI], 1.037–1.117; p < 0.001) and PLR (OR, 1.001; 95%CI, 1.000–1.003; p = 0.045) were significantly associated with unfavorable outcomes, the area under the receiver operating characteristic curve of NLR and PLR was 0.622 and 0.564, respectively. However, NLR, PLR, and MLR were not independently associated with sICH and 3-month mortality (all adjusted p > 0.05).ConclusionOverall, our results indicate that higher PLR and NLR were independently associated with unfavorable functional outcomes in AIS patients with successful recanalization after EVT; however, the underlying mechanisms are yet to be elucidated
Evaluation of nitrogen balance in a direct-seeded-rice field experiment using Hydrus-1D
Nitrogen (N) pollution is a global environmental problem that has greatly increased the risks of both the eutrophication of surface waters and contamination of ground waters. The majority of N pollution mainly comes from agricultural fields, in particular during rice growing seasons. In recent years, a gradual shift from the transplanting rice cultivation method to the direct seeding method has occurred, which results in different water and N losses from paddy fields and leads to distinct impacts on water environments. The N transport and transformations in an experimental direct-seeded-rice (DSR) field in the Taihu Lake Basin of east China were observed during two consecutive seasons, and simulated using Hydrus-1D model. The observed crop N uptake, ammonia volatilization (AV), N concentrations in soil, and N leaching were used to calibrate and validate the model parameters. The two most important inputs of N, i.e., fertilization and mineralization, were considered in the simulations with 220 and 145.5kgha-1 in 2008 and 220 and 147.8kgha-1 in 2009, respectively. Ammonia volatilization and nitrate denitrification were the two dominant pathways of N loss, accounting for about 16.0% and 38.8% of the total N input (TNI), respectively. Both nitrification and denitrification processes mainly occurred in the root zone. N leaching at 60 and 120cm depths accounted for about 6.8% and 2.7% of TNI, respectively. The crop N uptake was 32.1% and 30.8% of TNI during the 2008 and 2009 seasons, respectively, and ammonium was the predominant form (74% of the total N uptake on average). Simulated N concentrations and fluxes in soil matched well with the corresponding observed data. Hydrus-1D could simulate the N transport and transformations in the DSR field, and could thus be a good tool for designing optimal fertilizer management practices in the future
Morphological diversity of single neurons in molecularly defined cell types.
Dendritic and axonal morphology reflects the input and output of neurons and is a defining feature of neuronal types1,2, yet our knowledge of its diversity remains limited. Here, to systematically examine complete single-neuron morphologies on a brain-wide scale, we established a pipeline encompassing sparse labelling, whole-brain imaging, reconstruction, registration and analysis. We fully reconstructed 1,741 neurons from cortex, claustrum, thalamus, striatum and other brain regions in mice. We identified 11 major projection neuron types with distinct morphological features and corresponding transcriptomic identities. Extensive projectional diversity was found within each of these major types, on the basis of which some types were clustered into more refined subtypes. This diversity follows a set of generalizable principles that govern long-range axonal projections at different levels, including molecular correspondence, divergent or convergent projection, axon termination pattern, regional specificity, topography, and individual cell variability. Although clear concordance with transcriptomic profiles is evident at the level of major projection type, fine-grained morphological diversity often does not readily correlate with transcriptomic subtypes derived from unsupervised clustering, highlighting the need for single-cell cross-modality studies. Overall, our study demonstrates the crucial need for quantitative description of complete single-cell anatomy in cell-type classification, as single-cell morphological diversity reveals a plethora of ways in which different cell types and their individual members may contribute to the configuration and function of their respective circuits
Machine learning-based automatic construction of earthquake catalog for reservoir areas in multiple river basins of Guizhou province, ChinaKey points
Large reservoirs have the risk of reservoir induced seismicity. Accurately detecting and locating microseismic events are crucial when studying reservoir earthquakes. Automatic earthquake monitoring in reservoir areas is one of the effective measures for earthquake disaster prevention and mitigation. In this study, we first applied the automatic location workflow (named LOC-FLOW) to process 14-day continuous waveform data from several reservoir areas in different river basins of Guizhou province. Compared with the manual seismic catalog, the recall rate of seismic event detection using the workflow was 83.9%. Of the detected earthquakes, 88.9% had an onset time difference below 1 s, 81.8% has a deviation in epicenter location within 5 km, and 77.8% had a focal depth difference of less than 5 km, indicating that the workflow has good generalization capacity in reservoir areas. We further applied the workflow to retrospectively process continuous waveform data recorded from 2020 to the first half of 2021 in reservoir areas in multiple river basins of western Guizhou province and identified five times the number of seismic events obtained through manual processing. Compared with manual processing of seismic catalog, the completeness magnitude had decreased from 1.3 to 0.8, and a b-value of 1.25 was calculated for seismicity in western Guizhou province, consistent with the b-values obtained for the reservoir area in previous studies. Our results show that seismicity levels were relatively low around large reservoirs that were impounded over 15 years ago, and there is no significant correlation between the seismicity in these areas and reservoir impoundment. Seismicity patterns were notably different around two large reservoirs that were only impounded about 12 years ago, which may be explained by differences in reservoir storage capacity, the geologic and tectonic settings, hydrogeological characteristics, and active fault the reservoir areas. Prominent seismicity persisted around two large reservoirs that have been impounded for less than 10 years. These events were clustered and had relatively shallow focal depths. The impoundment of the Jiayan Reservoir had not officially begun during this study period, but earthquake location results suggested a high seismicity level in this reservoir area. Therefore, any seismicity in this reservoir area after the official impoundment deserves special attention
Experimental Study on the Effects of Discharge Chamber Length on 5 cm Radio-Frequency Ion Thruster
For keeping microgravity level of microgravity and space science satellites, a kind of electric thruster, the radio-frequency ion thruster (RIT) has been designed and applied. The RIT produces thrust through ionizing neutral particles in the discharge chamber and extracting ions by the ion optics system. The length of discharge chamber affects the ionization of neutral particles as well as the performance of RIT. In this paper, an experimental study has been carried out for analyzing the influence of discharge chamber length. In the experiment, the RIT-5 with various discharge chamber lengths, 27.6 mm, 30.0 mm, 31.9 mm, 35.5 mm, 40.0 mm, has different performances under the same condition. With the same radio frequency power and propellant flow rate, the RIT-5 has the optimal performance in beam current and efficiency when the discharge chamber length is 30.0 mm or 31.9 mm
Effects of different orchard tree pruning residues on the yield and nutrient composition of Lentinus edodes
IntroductionAs the scale of Lentinus edodes cultivation expands, challenges such as substrate shortages and rising production costs in mushroom cultivation have become increasingly prominent. Fruit tree pruning residue has the potential to serve as an alternative substrate, offering a sustainable solution. This study evaluates the feasibility of incorporating various types of fruit tree pruning residues into L. edodes cultivation.MethodsDifferent ratios of Quercus sawdust (QS), Malus pumila pruning (MPP), Vitis vinifera pruning (VVP), Actinidia deliciosa pruning (ADP), Ziziphus jujuba pruning (ZJP), and Morus alba pruning (MAP) were tested as substrates. The effects on yield, amino acid profiles, and protein content of L. edodes fruiting bodies were analyzed. The control substrate comprised 80% QS, and the experimental groups incorporated varying ratios of fruit tree residues.ResultsCompared with the control, yields increased by 14.86% (QS-MPP), 8.1% (QS-VVP), 18.92% (QS-ZJP), and 22.97% (QS-MAP). The MAP group had 21.21% higher ash content, while the QS-MAP group exhibited the highest crude protein content (10.84% increase). The QS-MPP group showed the highest crude fiber content (1.72 g/100 g). Crude polysaccharide and fat contents in the ZJP group increased by 110.77% and 10.15%, respectively. Mineral content varied, with QS-MPP showing the highest calcium, potassium, manganese, and magnesium levels, and VVP exhibiting the highest iron and copper levels. Amino acid analysis revealed QS-MPP had the highest levels of threonine, valine, isoleucine, serine, cysteine, glycine, and histidine, while QS-VVP had the highest leucine, aspartate, glutamate, and arginine levels. The best formulation was determined as 40% QS, 40% MPP, 17% bran, 1% sucrose, 1% CaCO3, and 1% gypsum.DiscussionThese results highlight the potential of fruit tree pruning residues as a sustainable substrate for L. edodes cultivation, ensuring high yields and enhanced nutritional quality. This approach can contribute to cost-effective and environmentally friendly mushroomproduction
Effect of Shale Sample Particle Size on Pore Structure Obtained from High Pressure Mercury Intrusion Porosimetry
With the rapid development of unconventional oil and gas, the pore structure characterization of shale reservoirs has attracted an increasing attention. High pressure mercury intrusion porosimetry (HPMIP) has been widely used to quantitatively characterize the pore structure of tight shales. However, the pore structure obtained from HPMIP could be significantly affected by the sample particle size used for the analyses. This study mainly investigates the influence of shale sample particle size on the pore structure obtained from HPMIP, using Mississippian-aged Barnett Shale samples. The results show that the porosity of Barnett Shale samples with different particle sizes obtained from HPMIP has an exponentially increasing relation with the particle size, which is mainly caused by the new pores or fractures created during shale crushing process as well as the increasing exposure of blind or closed pores. The amount and proportion of mercury retention during mercury extrusion process increase with the decrease of shale particle size, which is closely related to the increased ink-bottle effect in shale sample with smaller particle size. In addition, the fractal dimension of Barnett Shale is positively related to the particle size, which indicates that the heterogeneity of pore structure is stronger in shale sample with larger particle size. Furthermore, the skeletal density of shale sample increases with the decrease of particle size, which is possibly caused by the differentiation of mineral composition during shale crushing process
Study of electron-extraction characteristics of an inductively coupled radio-frequency plasma neutralizer
Abstract
Inductively coupled radio-frequency (RF) plasma neutralizer (RPN) is an insert-free device that can be employed as an electron source in electric propulsion applications. Electron-extraction characteristics of the RPN are related to the bulk plasma parameters and the device’s geometry. Therefore, the effects of different electron-extraction apertures and operational parameters upon the electron-extraction characteristics are investigated according to the global nonambipolar flow and sheath model. Moreover, these models can also be used to explain why the electron-extraction characteristics of the RPN strongly depend upon the formation of the anode spot. During the experimental study, two types of anode spots are observed. Each of them has unique characteristics of electron extraction. Moreover, the hysteresis of an anode spot is observed by changing the xenon volume-flow rates or the bias voltages. In addition, the rapid ignited method, gas-utilization factor, electron-extraction cost and other factors that need to be considered in the design of the RPN are also discussed