4,284 research outputs found
Stratifying the early radiologic trajectory in dyspneic patients with COVID-19 pneumonia
OBJECTIVE: This study aimed to stratify the early pneumonia trajectory on chest radiographs and compare patient characteristics in dyspneic patients with coronavirus disease 2019 (COVID-19).
MATERIALS AND METHODS: We retrospectively included 139 COVID-19 patients with dyspnea (87 men, 62.7+/-16.3 years) and serial chest radiographs from January to September 2020. Radiographic pneumonia extent was quantified as a percentage using a previously-developed deep learning algorithm. A group-based trajectory model was used to categorize the pneumonia trajectory after symptom onset during hospitalization. Clinical findings, and outcomes were compared, and Cox regression was performed for survival analysis.
RESULTS: Radiographic pneumonia trajectories were categorized into four groups. Group 1 (n = 83, 59.7%) had negligible pneumonia, and group 2 (n = 29, 20.9%) had mild pneumonia. Group 3 (n = 13, 9.4%) and group 4 (n = 14, 10.1%) showed similar considerable pneumonia extents at baseline, but group 3 had decreasing pneumonia extent at 1-2 weeks, while group 4 had increasing pneumonia extent. Intensive care unit admission and mortality were significantly more frequent in groups 3 and 4 than in groups 1 and 2 (P \u3c .05). Groups 3 and 4 shared similar clinical and laboratory findings, but thrombocytopenia ( \u3c 150x103/muL) was exclusively observed in group 4 (P = .016). When compared to groups 1 and 2, group 4 (hazard ratio, 63.3; 95% confidence interval, 7.9-504.9) had a two-fold higher risk for mortality than group 3 (hazard ratio, 31.2; 95% confidence interval, 3.5-280.2), and this elevated risk was maintained after adjusting confounders.
CONCLUSION: Monitoring the early radiologic trajectory beyond baseline further prognosticated at-risk COVID-19 patients, who potentially had thrombo-inflammatory responses
Origin of multi-level switching and telegraphic noise in organic nanocomposite memory devices.
The origin of negative differential resistance (NDR) and its derivative intermediate resistive states (IRSs) of nanocomposite memory systems have not been clearly analyzed for the past decade. To address this issue, we investigate the current fluctuations of organic nanocomposite memory devices with NDR and the IRSs under various temperature conditions. The 1/f noise scaling behaviors at various temperature conditions in the IRSs and telegraphic noise in NDR indicate the localized current pathways in the organic nanocomposite layers for each IRS. The clearly observed telegraphic noise with a long characteristic time in NDR at low temperature indicates that the localized current pathways for the IRSs are attributed to trapping/de-trapping at the deep trap levels in NDR. This study will be useful for the development and tuning of multi-bit storable organic nanocomposite memory device systems
Characteristics of injury of the corticospinal tract and corticoreticular pathway in hemiparetic patients with putaminal hemorrhage
BACKGROUND: No study on the characteristics of injury of the corticospinal tract (CST) or corticoreticular pathway (CRP) in patients with putaminal hemorrhage has been reported. In this study, using diffusion tensor tractography, we attempted to investigate the characteristics of injury of the CST and CRP in hemiparetic patients with putaminal hemorrhage. METHOD: Fifty seven consecutive patients with putaminal hemorrhage and 57 healthy control subjects were recruited for this study. Diffusion tensor imaging was performed during the early period (8 ~ 30 days) after onset. We defined injury of the CST or CRP in terms of the configuration (discontinuation of a neural tract) or abnormal DTT parameters (the fractional anisotrophy value or fiber number was more than two standard deviations lower than that of normal control subjects). The Motricity Index, the modified Brunnstrom Classification, and the Functional Ambulation Categories were used for evaluation of motor function. RESULTS: Among 57 patients, injury of the CST was found in 41 patients (71.9%) and injury of the CRP was found in 50 patients (87.8%), respectively, and 37 patients (64.9%) had injury of both the CST and CRP. All three motor functions of patients with injury of both the CST and CRP were significantly lower than those of patients with injury of either the CST or CRP (p < 0.05). CONCLUSION: Our results indicate that the putaminal hemorrhage frequently accompanies injury of both the CST and CRP, and the CRP appears to be more vulnerable to putaminal hemorrhage than the CST. These findings suggest the necessity for evaluation of both the CRP and the CST in patients with putaminal hemorrhage
Development of Practical Design Approaches for Water Distribution Systems
The optimal design of water distribution systems (WDSs) should be economical, consider practical field applicability, and satisfy hydraulic constraints such as nodal pressure and flow velocity. However, the general optimal design of a WDSs approach using a metaheuristic algorithm was difficult to apply for achieving pipe size continuity at the confluence point. Although some studies developed the design approaches considering the pipe continuity, these approaches took many simulation times. For these reasons, this study improves the existing pipe continuity search method by reducing the computation time and enhancing the ability to handle pipe size continuity at complex joints that have more than three nodes. In addition to more practical WDSs designs, the approach considers various system design factors simultaneously in a multi-objective framework. To verify the proposed approach, the three well-known WDSs to apply WDS design problems are applied, and the results are compared with the previous design method, which used a pipe continuity research algorithm. This study can reduce the computation time by 87% and shows an ability to handle complex joints. Finally, the application of this practical design technique, which considers pipe continuity and multiple design factors, can reduce the gap between the theoretical design and the real world because it considers construction conditions and abnormal situations.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Generation of high concentration nanobubbles based on friction tubes
Nanobubble-related technologies have been confirmed to be useful in various
fields such as climate change and the environment as well as water-based
industries such as water purification, crops, horticulture, medical care, bio,
and sterilization. However, a method of mass production in real time enough to
apply nano-bubbles to the industry has not yet been developed. We explored the
mechanism of nano-bubble water generation by friction between water and walls
and developed a tube device applying the shape of the flow path to maximize the
friction in the fluid passing through the flow path. It also describes the case
of real-time and low-power mass production of nanobubbles and its technical
utility. We found that the friction of nanotubes alone can easily and quickly
improve the production of nanobubbles with small particle size in real time; by
increasing the shearing pressure while increasing the effective friction
constant value, the particle size of nanobubbles can be smaller while
increasing the particle concentration.Comment: 24 pages, 24 figures, 6 table
Friction Tubes to Generate Nanobubble Ozone Water with an Increased Half-Life for Virucidal Activity
Nanobubbles and related technologies are expected to be highly utilized in
water resource-based industries such as water purification, crops,
horticulture, medicine, bio, and sterilization. Ozone, a chemical with high
sterilizing power, is known as a natural substance that is reduced to oxygen
and water after reacting with pollutants. Ozone water, which is generated by
dissolving ozone in water, has been used in various industrial sectors such as
medical care, food, and environment. Due to the unstable molecular state of
ozone, however, it is difficult to produce, use, and supply ozone at industrial
sites in a stable manner. This study proposed a method for constructing a
system that can generate high-concentration ozone water in large quantities
using low power in real time and maintaining the concentration of the generated
ozone water over the long term. Friction tubes (called 'nanotube') played a key
role to generate nanobubble ozone water with an increased half-life for virus
killing activity. In addition, the safety of ozone water during its spray into
the air was explained, and virucidal activity test cases for the influenza A
(H1N1/A/PR8) and COVID-19 (SARS-CoV-2) virus using high-concentration ozone
water as well as its technical efficacy were described
A case study on swell correction of Chirp sub-bottom profiler (SBP) data using multi-beam echo sounder (MBES) data
High-resolution marine seismic data acquisition and subsequent analyses are highly influenced by sea conditions, directly affecting data quality and interpretation. Traditional swell effect correction methods are effective in improving reflector continuity; however, they are less useful for enhancing travel time consistency at intersection points of crossing lines. To develop a robust swell-removal technique for a set of crossing lines multi-beam echo sounder (MBES) data and Chirp sub-bottom profiler (SBP) data were acquired. After generation of a time structure map of the sea-bottom converted from the final processed multi-beam data, a moving average was used to improve the event continuity of the sea-bottom reflection of the Chirp SBP data. Using the position of the Chirp SBP data, the difference between the travel time of the sea-bottom from the smoothed map and the original travel time of the sea-bottom is calculated as a static correction. The static correction method based on the MBES data was compared and verified using three different cases: (i) simple 2D swell effect correction on a line-by-line basis, (ii) comparing the swell corrections at the crossing positions of 2D lines acquired from different dates, and (iii) comparison of ties of intersection points between 2D lines after new swell correction applied. Although a simple 2D swell correction showed great enhancement of reflector continuity, only the full static correction using the newly proposed method using MBES data produced completely corrected reflection events especially at the crossing points of 2D lines
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