1,597 research outputs found
Thoracic Injuries in earthquake-related versus non-earthquake-related trauma patients: differentiation via Multi-detector Computed Tomography
PURPOSE: Massive earthquakes are harmful to humankind. This study of a historical cohort aimed to investigate the difference between earthquake-related crush thoracic traumas and thoracic traumas unrelated to earthquakes using a multi-detector Computed Tomography (CT). METHODS: We retrospectively compared an earthquake-exposed cohort of 215 thoracic trauma crush victims of the Sichuan earthquake to a cohort of 215 non-earthquake-related thoracic trauma patients, focusing on the lesions and coexisting injuries to the thoracic cage and the pulmonary parenchyma and pleura using a multi-detector CT. RESULTS: The incidence of rib fracture was elevated in the earthquake-exposed cohort (143 vs. 66 patients in the non-earthquake-exposed cohort, Risk Ratio (RR) = 2.2; p<0.001). Among these patients, those with more than 3 fractured ribs (106/143 vs. 41/66 patients, RR=1.2; p<0.05) or flail chest (45/143 vs. 11/66 patients, RR=1.9; p<0.05) were more frequently seen in the earthquake cohort. Earthquake-related crush injuries more frequently resulted in bilateral rib fractures (66/143 vs. 18/66 patients, RR= 1.7; p<0.01). Additionally, the incidence of non-rib fracture was higher in the earthquake cohort (85 vs. 60 patients, RR= 1.4; p<0.01). Pulmonary parenchymal and pleural injuries were more frequently seen in earthquake-related crush injuries (117 vs. 80 patients, RR=1.5 for parenchymal and 146 vs. 74 patients, RR = 2.0 for pleural injuries; p<0.001). Non-rib fractures, pulmonary parenchymal and pleural injuries had significant positive correlation with rib fractures in these two cohorts. CONCLUSIONS: Thoracic crush traumas resulting from the earthquake were life threatening with a high incidence of bony thoracic fractures. The ribs were frequently involved in bilateral and severe types of fractures, which were accompanied by non-rib fractures, pulmonary parenchymal and pleural injuries
Realization of Zero-Refractive-Index Lens with Ultralow Spherical Aberration
Optical complex materials offer unprecedented opportunity to engineer
fundamental band dispersion which enables novel optoelectronic functionality
and devices. Exploration of photonic Dirac cone at the center of momentum space
has inspired an exceptional characteristic of zero-index, which is similar to
zero effective mass in fermionic Dirac systems. Such all-dielectric zero-index
photonic crystals provide an in-plane mechanism such that the energy of the
propagating waves can be well confined along the chip direction. A
straightforward example is to achieve the anomalous focusing effect without
longitudinal spherical aberration, when the size of zero-index lens is large
enough. Here, we designed and fabricated a prototype of zero-refractive-index
lens by comprising large-area silicon nanopillar array with plane-concave
profile. Near-zero refractive index was quantitatively measured near 1.55 um
through anomalous focusing effect, predictable by effective medium theory. The
zero-index lens was also demonstrated to perform ultralow longitudinal
spherical aberration. Such IC compatible device provides a new route to
integrate all-silicon zero-index materials into optical communication, sensing,
and modulation, and to study fundamental physics on the emergent fields of
topological photonics and valley photonics.Comment: 14 pages, 4 figure
Earthquake-related versus non-earthquake-related injuries in spinal injury patients: differentiation with multidetector computed tomography
Ethyl 4-[(4-chlorophenoxy)methyl]-2-(4-nitrophenyl)-1,3-thiazole-5-carboxylate
The title compound, C19H15ClN2O5S, contains two molecules (A and B) in the asymmetric unit. In molecule A, the dihedral angles between the thiazole ring and the pendant chlorobenzene and nitrobenzene rings are 72.14 (15) and 3.03 (15)°, respectively. The corresponding angles for molecule B are 45.56 (16) and 1.51 (14)°, respectively. In the crystal, both molecules form inversion dimers linked by pairs of weak C—H⋯O interactions
Earthquake-related Crush Injury versus Non-Earthquake Injury in Abdominal Trauma Patients on Emergency Multidetector Computed Tomography: A Comparative Study
The aim of this study was to investigate features of abdominal earthquake-related crush traumas in comparison with non-earthquake injury. A cross sectional survey was conducted with 51 survivors with abdominal crush injury in the 2008 Sichuan earthquake, and 41 with abdominal non-earthquake injury, undergoing non-enhanced computed tomography (CT) scans, serving as earthquake trauma and control group, respectively. Data were analyzed between groups focusing on CT appearance. We found that injury of abdominal-wall soft tissue and fractures of lumbar vertebrae were more common in earthquake trauma group than in control group (28 vs 13 victims, and 24 vs 9, respectively; all P < 0.05); and fractures were predominantly in transverse process of 1-2 vertebrae among L1-3 vertebrae. Retroperitoneal injury in the kidney occurred more frequently in earthquake trauma group than in control group (29 vs 14 victims, P < 0.05). Abdominal injury in combination with thoracic and pelvic injury occurred more frequently in earthquake trauma group than in control group (43 vs 29 victims, P < 0.05). In conclusion, abdominal earthquake-related crush injury might be characteristic of high incidence in injury of abdominal-wall soft tissue, fractures of lumbar vertebrae in transverse process of 1-2 vertebrae among L1-3 vertebrae, retroperitoneal injury in the kidney, and in combination with injury in the thorax and pelvis
A Transmissive X-ray Polarimeter Design For Hard X-ray Focusing Telescopes
The X-ray Timing and Polarization (XTP) is a mission concept for a future
space borne X-ray observatory and is currently selected for early phase study.
We present a new design of X-ray polarimeter based on the time projection gas
chamber. The polarimeter, placed above the focal plane, has an additional rear
window that allows hard X-rays to penetrate (a transmission of nearly 80% at 6
keV) through it and reach the detector on the focal plane. Such a design is to
compensate the low detection efficiency of gas detectors, at a low cost of
sensitivity, and can maximize the science return of multilayer hard X-ray
telescopes without the risk of moving focal plane instruments. The sensitivity
in terms of minimum detectable polarization, based on current instrument
configuration, is expected to be 3% for a 1mCrab source given an observing time
of 10^5 s. We present preliminary test results, including photoelectron tracks
and modulation curves, using a test chamber and polarized X-ray sources in the
lab
Characteristics of coronary artery disease in symptomatic type 2 diabetic patients: evaluation with CT angiography
<p>Abstract</p> <p>Background</p> <p>Coronary artery disease (CAD) is a common and severe complication of type 2 diabetes mellitus (DM). The aim of this study is to identify the features of CAD in diabetic patients using coronary CT angiography (CTA).</p> <p>Methods</p> <p>From 1 July 2009 to 20 March 2010, 113 consecutive patients (70 men, 43 women; mean age, 68 ± 10 years) with type 2 DM were found to have coronary plaques on coronary CTA. Their CTA data were reviewed, and extent, distribution and types of plaques and luminal narrowing were evaluated and compared between different sexes.</p> <p>Results</p> <p>In total, 287 coronary vessels (2.5 ± 1.1 per patient) and 470 segments (4.2 ± 2.8 per patient) were found to have plaques, respectively. Multi-vessel disease was more common than single vessel disease (<it>p </it>< 0.001), and the left anterior descending (LAD) artery (35.8%) and its proximal segment (19.1%) were most frequently involved (all <it>p </it>< 0.001). Calcified plaques (48.8%) were the most common type (<it>p </it>< 0.001) followed by mixed plaques (38.1%). Regarding the different degrees of stenosis, mild narrowing (36.9%) was most common (<it>p </it>< 0.001); however, a significant difference was not observed between non-obstructive and obstructive stenosis (50.4% vs. 49.6%, <it>p </it>= 0.855). Extent of CAD, types of plaques and luminal narrowing were not significantly different between male and female diabetic patients.</p> <p>Conclusions</p> <p>Coronary CTA depicted a high plaque burden in patients with type 2 DM. Plaques, which were mainly calcified, were more frequently detected in the proximal segment of the LAD artery, and increased attention should be paid to the significant prevalence of obstructive stenosis. In addition, DM reduced the sex differential in CT findings of CAD.</p
DeepCF: A Unified Framework of Representation Learning and Matching Function Learning in Recommender System
In general, recommendation can be viewed as a matching problem, i.e., match
proper items for proper users. However, due to the huge semantic gap between
users and items, it's almost impossible to directly match users and items in
their initial representation spaces. To solve this problem, many methods have
been studied, which can be generally categorized into two types, i.e.,
representation learning-based CF methods and matching function learning-based
CF methods. Representation learning-based CF methods try to map users and items
into a common representation space. In this case, the higher similarity between
a user and an item in that space implies they match better. Matching function
learning-based CF methods try to directly learn the complex matching function
that maps user-item pairs to matching scores. Although both methods are well
developed, they suffer from two fundamental flaws, i.e., the limited
expressiveness of dot product and the weakness in capturing low-rank relations
respectively. To this end, we propose a general framework named DeepCF, short
for Deep Collaborative Filtering, to combine the strengths of the two types of
methods and overcome such flaws. Extensive experiments on four publicly
available datasets demonstrate the effectiveness of the proposed DeepCF
framework
Simulation of Microstructure during Laser Rapid Forming Solidification Based on Cellular Automaton
The grain microstructure of molten pool during the solidification of TC4 titanium alloy in the single point laser cladding was investigated based on the CAFE model which is the cellular automaton (CA) coupled with the finite element (FE) method. The correct temperature field is the prerequisite for simulating the grain microstructure during the solidification of the molten pool. The model solves the energy equation by the FE method to simulate the temperature distribution in the molten pool of the single point laser cladding. Based on the temperature field, the solidification microstructure of the molten pool is also simulated with the CAFE method. The results show that the maximum temperature in the molten pool increases with the laser power and the scanning rate. The laser power has a larger influence on the temperature distribution of the molten pool than the scanning rate. During the solidification of the molten pool, the heat at the bottom of the molten pool transfers faster than that at the top of the molten pool. The grains rapidly grow into the molten pool, and then the columnar crystals are formed. This study has a very important significance for improving the quality of the structure parts manufactured through the laser cladding forming
- …