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The identification of biomacromolecules by using surface-enhanced Raman scattering (SERS) remains a challenge because of the near-field effect of traditional substrates. Long-range surface plasmon resonance (LRSPR) is a special type of surface optical phenomenon that provides higher electromagnetic field enhancement and longer penetration depth than conventional surface plasmon resonance. To break the limit of SERS detection distance and obtain a SERS substrate with increased enhancement ability, a bowtie nanoaperture array was sandwiched between two symmetric dielectric environments. Then, an Au mirror was inserted to form a metal-insulator-metal configuration. Finite-difference time-domain simulations revealed that numerous hybrid modes can be provided by this novel configuration (denoted as long-range SERS [LR-SERS] substrate). In particular, the LRSPR mode can be excited and reach the maximum value through the regulation of the polarizations of the incident light and the geometrical parameters of the LR-SERS substrate. The optimized LR-SERS substrate was then applied to detect SARS-CoV-2 spike (S) and nucleocapsid (N) proteins. This substrate displayed ultralow detection limits of ∼9.2 and ∼11.3 pg mL

Aims: To investigate the diagnostic value of dual-energy computed tomography (DECT) in Acute Gouty Arthritis (AGA) or patients presenting suspected gouty arthritis. Methods: This retrospective study was performed in a single centre from May 2017 to August 2018. Two hundred and twenty-six patients with an initial diagnosis of AGA in the preceding 15 days were included. All patients were referred for a DECT scan of the affected joints. The diagnosis criteria of gout with the American College of Rheumatology Classification Standard were regarded as the reference standard. Results: After filtration, two hundred patients were included in the present study. The sensitivity, specificity, positive predictive value, and negative predictive value of DECT in the diagnosis of all AGA were 83.83%, 60.61%, 91.5%, and 42.55%, respectively. When AGA was subdivided according to the joint site, the sensitivity, specificity, positive predictive value, and negative predictive value were 80.68%, 61.11%, 91.03%, and 39.29% in feet, 93.55%, 40%, 93.55%, and 40% in knees and 87.5%, 71.43%, 91.3%, and 62.5% in ankles, respectively. Conclusions: DECT had a high sensitivity for the diagnosis of AGA. However, the specificity was limited, particularly for the diagnosis of acute gouty knee arthritis. Prospective multicenter studies of large samples will enhance the application of DECT among AGA patients in the future.

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A novel curved surface nanowire target is proposed to improve the cutoff energy of accelerated protons via target normal sheath acceleration. The interaction of a laser of intensity $1.37\times 10^{20}\ {\rm W}\ {\rm cm}^{-2}$ with a curved surface nanowire target is studied by two-dimensional particle-in-cell simulations. The numerical results indicate that the sheath electric field at the target rear side is significantly enhanced by this simple target design, compared with using the planar nanowire target. The transverse motion of hot electrons is effectively confined and the energy density of electrons is naturally increased. A series of simulations with various target parameters is carried out to investigate the performance of this novel target. This tailored target may provide implications for generating high-quality proton beams in experiments.

Apoptosis of alveolar epithelial cells during acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a critical pathological event that seriously endangers the health of patients. Suppressing apoptosis of alveolar epithelial cells was shown to alleviate functional damage of lung, and modulator of the reactive oxygen species (ROS)-induced apoptosis becomes a promising approach to the ALI therapy. Previous little studies showed that DHCR24 possessed anti-oxidative and anti-apoptotic property in ALI. Thus, H2O2 was utilized to mimic oxidative damage in vitro in alveolar epithelial cell line A549 in the present study. Our results exhibited that H2O2 treatment of A549 cells reduced the level of SOD and increased the level of ROS. Moreover, H2O2 inhibited Bcl-2 expression in A549 cells, but increased Bax and the activity of Caspase-3. In addition, the apoptosis rate in the H2O2 treatment group also increased significantly. And the expression of 24-dehydrocholesterol reductase (DHCR24) was markedly reduced in the H2O2 treatment group. Overexpression of DHCR24 can remarkably inhibit H2O2-induced oxidative stress and apoptosis. We found that overexpression of DHCR24 increased the phosphorylation level of PI3K and AKT, however, the PI3K inhibitor LY294002 (LY) eliminated the protective effect of DHCR24 in ALI. DHCR24 was down-regulated in H2O2-induced ALI, and overexpression of DHCR24 could inhibit H2O2-induced oxidative stress and apoptosis of A549 cells by activating the Phosphatidylinositol-3-Kinase/Protein Kinase B (PI3K/AKT) signaling pathway. The above exhibited a protective effect of DHCR24 on alveolar epithelial cells exposed to oxidative stress-mediated apoptosis and provided a novel therapeutic method for ALI.

Welding repair has been widely used to restore the structural integrity of coke drums compromised by cracks due to low-cycle fatigue failure among other damaging mechanisms. Nevertheless, due to the heterogeneous mechanical and metallurgical properties, repair welds are susceptible to re-cracking during subsequent operations. The API 1996 report has shown that 88% of outer-diameter (OD) repair welds have experienced re-cracking in coke drums. The re-cracking susceptibility downgrades the efficiency of welding repair to extend coke drum operation life and may increase the complexity of coke drum maintenance. Hence, addressing the low-cycle fatigue failure of weld becomes a critical issue to optimize welding repair for coke drum maintenance. Alloy 625 is a commonly used Ni-based filler metal to perform coke drum repairs due to its good thermal and metallurgical compatibility with the base metal. However, weld metal dilution close to the weld interface changes local microstructure and mechanical properties from the rest part of the weld. In this study, an external repair welds of 1.25Cr-0.5Mo steel under as-received (Normalized and Tempered) and service-aged conditions with Alloy 625 using HP-GTAW process are evaluated based on low-cycle fatigue tests and failure analysis. Weld transition samples are extracted to encompass the transition from weld metal to base metal at the gage section. Low-cycle fatigue tests are performed at 0.7%, 1.0%, 1.5% and 2.0% strain amplitudes. Interfacial cracks are observed at lower strain amplitudes (0.7% and 1.0%) and failures at higher strain amplitudes tend to occur at the base metal region. Metallurgical characterizations are performed to characterize the microstructure at weld interface and measure the mechanical properties through micro hardness. Interfacial cracks are examined using Scanning Electron Microscopy. This study helps clarify how microstructure and mechanical properties contribute to the interfacial cracking of the Ni-base alloy and steel dissimilar joint.

Background Limited studies have investigated the accuracy of therapeutic decision-making using machine learning-based coronary computed tomography angiography (ML-CCTA) compared with CCTA. Purpose To investigate the performance of ML-CCTA for therapeutic decision compared with CCTA. Material and Methods The study population consisted of 322 consecutive patients with stable coronary artery disease. The SYNTAX score was calculated with an online calculator based on ML-CCTA results. Therapeutic decision-making was determined by ML-CCTA results and the ML-CCTA-based SYNTAX score. The therapeutic strategy and the appropriate revascularization procedure were selected using ML-CCTA, CCTA, and invasive coronary angiography (ICA) independently. Results The sensitivity, specificity, positive predictive value, negative predictive value, accuracy of ML-CCTA and CCTA for selecting revascularization candidates were 87.01%, 96.43%, 95.71%, 89.01%, 91.93%, and 85.71%, 87.50%, 86.27%, 86.98%, 86.65%, respectively, using ICA as the standard reference. The area under the receiver operating characteristic curve (AUC) of ML-CCTA for selecting revascularization candidates was significantly higher than CCTA (0.917 vs. 0.866, P = 0.016). Subgroup analysis showed the AUC of ML-CCTA for selecting percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) candidates was significantly higher than CCTA (0.883 vs. 0.777, P Conclusion ML-CCTA could distinguish between patients who need revascularization and those who do not. In addition, ML-CCTA showed a slightly superior to CCTA in making an appropriate decision for patients and selecting a suitable revascularization strategy.

The effects of magnetic vortex acceleration (MVA) are investigated with two-dimensional particle-in-cell (PIC) simulations by laser interaction with near-critical density (NCD) plasma inside a hollow conical plasma. Energetic and collimated proton beams can be accelerated by a longitudinal charge-separation field. Energetic protons with a peak energy of 220 MeV are produced in PIC simulations. Compared with a uniform NCD plasma, both the cutoff energy and collimation of proton beams are improved remarkably. Furthermore, the influence of different gap sizes of cone tip is taken into account. For optimizing magnetic vortex acceleration, the gap size of the cone tip is suggested to match the focal spot size of laser pulse.

Background The study sought to compare Coronary Artery Disease Reporting and Data System (CAD-RADS) classification with traditional coronary artery disease (CAD) classifications and Duke Prognostic CAD Index for predicting the risk of all-cause mortality in patients with suspected CAD. Methods 9625 consecutive suspected CAD patients were assessed by coronary CTA for CAD-RADS classification, traditional CAD classifications and Duke Prognostic CAD Index. Kaplan–Meier and multivariable Cox models were used to estimate all-cause mortality. Discriminatory ability of classifications was assessed using time dependent receiver-operating characteristic (ROC) curves and The Hosmer–Lemeshow goodness-of-fit test was employed to evaluate calibration. Results A total of 540 patients died from all causes with a median follow-up of 4.3 ± 2.1 years. Kaplan–Meier survival curves showed the cumulative events increased significantly associated with CAD-RADS, three traditional CAD classifications and Duke Prognostic CAD Index. In multivariate Cox regressions, the risk for the all-cause death increased from HR 0.861 (95% CI 0.420–1.764) for CAD-RADS 1 to HR 2.761 (95% CI 1.961–3.887) for CAD-RADS 4B&5, using CAD-RADS 0 as the reference group. The relative HRs for all-cause death increased proportionally with the grades of the three traditional CAD classifications and Duke Prognostic CAD Index. The area under the time dependent ROC curve for prediction of all-cause death was 0.7917, 0.7805, 0.7991for CAD-RADS in 1 year, 3 year, 5 year, respectively, which was non-inferior to the traditional CAD classifications and Duke Prognostic CAD Index. Conclusions The CAD-RADS classification provided important prognostic information for patients with suspected CAD with noninvasive evaluation, which was non-inferior than Duke Prognostic CAD Index and traditional stenosis-based grading schemes in prognostic value of all-cause mortality. Traditional and simplest CAD classification should be preferable, given the more number of groups and complexity of CAD-RADS and Duke prognostic index, without using more time consuming classification.

Background: To explore the effects of postoperative adjuvant transarterial chemoembolization (PA-TACE) on the prognosis of HCC patients with Portal Vein Tumor Thrombus (PVTT) undergoing resection, and to develop a PA-TACE-related nomogram for predicting survival individually. Patients and Methods: Two hundred and ninety-three consecutive HCC patients with PVTT under R0 hepatectomy were recruited. Forty-seven cases had recurrence within one month after surgery. The remaining 246 cases consisted of 90 PA-TACE and 156 non-PA-TACE cases. COX regression analysis was performed for overall survival (OS) or recurrence-free survival (RFS) of these 246 cases, allowing the derivation of independent factors that were integrated into the nomogram. C-index, calibration curves, and risk stratification were performed to evaluate the performance and discriminative power of the nomograms. Results: In 246 patients without recurrence within one month after surgery, the OS and RFS for the PA-TACE group were significantly better than those for the non-PA-TACE group (P

Low-cycle fatigue failure has been widely accepted as the key mechanism causing damages of coke drums during cyclic thermal-mechanical loadings. Common damages of coke drums known as bulging and cracking are associated with accumulative plasticity caused by thermal and mechanical strains. External repairs using temper-bead welding techniques are implemented to repair welds in the damaged areas of coke drums, which provide structural support to the vessels. Compared with matching filler metals, Ni-base fillers including alloy 625 and alloy 182 are compatible with both low-alloy steel base metal and internal clads in terms of weldability and thermal expansion. However, the differences of yield strengths and cyclic hardening behaviors of nickel-base alloys from base metals compromise the fatigue resistances of weld joints. In this study, alloy 182 and alloy 625 repair coupons were evaluated and compared based on isothermal low-cycle fatigue tests. Low-cycle fatigue behaviors of both weld metals and 1.25Cr-0.5Mo base metal were measured at 1.0%, 1.5% and 2.0% strain amplitudes. Test results indicate both nickel-base filler metals exhibit overmatching strength over the base metal due to cyclic hardening. Low-cycle fatigue tests of Heat Affected zone (HAZ) samples show the failures of alloy 625 weld joints occur in the base metal, while the failures of alloy 182 weld joints occur along the fusion boundary. The observations show strength mismatch and fatigue resistance are the key factors to determine failure locations of the joints. In addition, cyclic hardening coefficients based on kinematic hardening model were extracted from experimental data to simulate the cyclic behaviors of the weld joints. Finite element simulation results were shown to be consistent with experimental data at stabilized cycles. Cyclic behaviors of weld metal and base metal within a weld transition sample were calculated based on the numerical model.

Hoverable Flapping Wing Micro Air Vehicle (FWMAV) is a new concept aircraft which imitates the flight mode of hummingbirds or insects. It has excellent mobility, flexibility, concealment, and can demonstrate hovering, forward flight and other maneuvers, which has attracted wide attention. In this research, a prototype of hoverable FWMAVs is designed and built for the research of control method, and the research on flight attitude estimation and attitude control algorithm are carried out. The hardware devices such as flight control board and remote control are designed and developed independently, also we devised the software control system to realize the communication between software and hardware, then the algorithm is verified on the experimental platform. The prototype of the aircraft weighs 27.24g, and can take off under the flapping frequency of 20Hz. On the experimental platform, relying on the hardware control circuit and software control algorithm, it can realize the attitude control of roll and pitch, and demonstrate hovering flight for two minutes.

Background: The coronary artery disease reporting and data system (CAD-RADSTM) was recently introduced for standard reporting. We aimed to evaluate the utility of an automatic post-processing and reporting system based on CAD-RADS in suspected CAD patients.Methods: The clinical evaluation was encompassed 346 patients who underwent coronary computed tomography angiography (CCTA). We compared deep learning (DL)-based CCTA with Readers for classification of CAD-RADS with commercially-available automated segmentation and manual post-processing in a prospective validation cohort. Results: Compared with invasive coronary angiography (ICA), the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of DL model for diagnosis of CAD were 79.02%, 86.52%, 89.50%, 73.94% and 82.08%, respectively. There was no significant difference between the DL-based and Readers-based CAD-RADS grading in CCTA. The consistency test showed that the Kappa value between the model and Readers was 0.775 (95% CI: 0.728-0.823, P < 0.001), 0.802 (95% CI: 0.756-0.847, P95% CI: 0.750-0.843, P < 0.001), respectively. This system reduces the time consumed from 14.97 ± 1.80 min to 5.02 ± 0.8 min (P < 0.001).Conclusion: The standardized report of DL-based CAD-RADS in CCTA can accurately evaluate suspected CAD patients with time-saving, and has good consistency with the radiologists.

Background: Nonalcoholic fatty liver disease has attracted considerable attention with continuously increasing morbidity. Objective: To evaluate the aortic distensibility in patients with non-diabetic and hypertension-type Nonalcoholic Fatty Liver Disease (NAFLD) through Dual-Source Computed Tomography (DSCT). Method: 120 patients with NAFLD (experimental group) and 30 healthy subjects (control group) were consecutively enrolled in the study. In the two groups, aortic distensibility was calculated as D = ΔA/(A0 ×Δp). Record fasting insulin, fasting blood glucose, fasting lipid status, age, heart rate, waist circumference, systolic blood pressure, and diastolic blood pressure. Calculate homeostasis model assessment of insulin resistance (HOMA-IR) and Body Mass Index (BMI). A comparative analysis between the two groups was carried out, followed by a correlation analysis between D value and risk factors. Results: D value and liver attenuation of the patients in the NAFLD group were significantly reduced relative to those in the control group (2.24±0.63×10-3 mmHg-1 vs. 3.19±0.86×10-3 mmHg-1, P Conclusion: Patients with NAFLD suffer from a reduction in aortic distensibility, and insulin resistance may play a significant role in the early atherosclerosis stage.

Coke drums are pressure vessels used in the delayed coking process at oil refineries, which transform heavy residual oil into light-weight hydrocarbon molecules and solid coke through thermal cracking. Due to the severe thermal and mechanical loadings during operation, these vessels experienced low-cycle fatigue failure, which led to shell and skirt damage such as bulging and cracking. External weld repairs using the temper bead technique have been widely applied to repair damaged regions caused by bulging and cracking for preventing the leaks of the residual oil contents. However, a substantial proportion of the external repairs have been reported to experience post-repair cracking issues. In this study, an external weld repair mockup with a backing plate was evaluated through metallurgical characterizations and isothermal low-cycle fatigue tests. The micro-hardness mapping identified the mismatching interfaces from base metal to weld metal (WM) and from root passes to internal clad. Four types of dog-bone samples were extracted from the weld: weld metal, heat affected zone, internal clad and backing plate. These samples were used to evaluate the fatigue resistance of weld metal and transition zone under low-cycle fatigue tests. Failure analysis showed that weld metal samples were susceptible to multiple-crack initiations, while other transition samples failed at mismatching interfaces or stress concentration points at weld toes.

The aim of this study was to describe clinical, imaging, and laboratory features of acute pulmonary embolism (APE) in patients with COVID-19 associated pneumonia. Patients with COVID-19 associated pneumonia who underwent a computed tomography pulmonary artery (CTPA) scan for suspected APE were retrospectively studied. Laboratory data and CTPA images were collected. Imaging characteristics were analyzed descriptively. Laboratory data were analyzed and compared between patients with and without APE. A series of 25 COVID-19 patients who underwent CTPA between January 2020 and February 2020 were enrolled. The median D-dimer level founded in these 25 patients was 6.06 μg/mL (interquartile range [IQR] 1.90-14.31 μg/mL). Ten (40%) patients with APE had a significantly higher level of D-dimer (median, 11.07 μg/mL; IQR, 7.12-21.66 vs median, 2.44 μg/mL; IQR, 1.68-8.34, respectively, P = .003), compared with the 15 (60%) patients without APE. No significant differences in other laboratory data were found between patients with and without APE. Among the 10 patients with APE, 6 (60%) had a bilateral pulmonary embolism, while 4 had a unilateral embolism. The thrombus-prone sites were the right lower lobe (70%), the left upper lobe (60%), both upper lobe (40%) and the right middle lobe (20%). The thrombus was partially or completely absorbed after anticoagulant therapy in 3 patients who underwent a follow-up CTPA. Patients with COVID-19 associated pneumonia have a risk of developing APE during the disease. When the D-dimer level abnormally increases in patients with COVID-19 pneumonia, CTPA should be performed to detect and assess the severity of APE.

This study sought to evaluate the association of breast arterial calcification (BAC) on breast screening mammography with the Coronary Artery Disease-Reporting and Data System (CAD-RADS) based on Deep Learning-coronary computed tomography angiography (CCTA). This prospective single institution study included asymptomatic women over 40 who underwent CCTA and breast cancer screening mammography between July 2018 and April 2019. CAD-RADS was scored based on Deep Learning (DL). Mammograms were assessed visually for the presence of BAC. A total of 213 patients were included in the analysis. In comparison to the low CAD-RADS (CAD-RADS P = 0.036), diabetes (P = 0.017), and chronic kidney disease (P = 0.006). They also had a significantly higher level of LDL-C (P = 0.024), while HDL-C was lower than in the low CAD-RADS group (P = 0.003). BAC was also significantly higher in the high CAD-RADS group (P = 0.002). In multivariate analysis, the presence of BAC [odd ratio (OR) 10.22, 95% CI 2.86–36.49, P

To study chest CT images and clinical characteristics of COVID-19 pneumonia in pregnant patients to examine any correlation.Between December 31, 2019 and March 7, 2020, 23 hospitalized pregnant patients with confirmed COVID-19 were enrolled in the study. Clinical presentations were collected retrospectively from records, including laboratory testing, chest CT imaging, and symptoms. Descriptive analysis and correlation of patients' clinical and CT characteristics were performed. Laboratory results from time of first admission and CT absorption (defined as reduction in lesion area, decrease in density, and absorption of some solid components) were compared between symptomatic and asymptomatic patients.Fifteen (65.2%) patients were asymptomatic with patchy ground-glass opacity in a single lung lobe. Eight (34.8%) patients were symptomatic with multiple patchy ground-glass shadows, consolidation, and fibrous stripes. Differences in lymphocyte percentage and neutrophil granulocyte rate between first admission and CT absorption were significant (P0.001). Median absorption time was shorter in the asymptomatic group compared with the symptomatic group (5 vs 10 days; P0.001). Median hospitalization time between asymptomatic and symptomatic patients was 14 vs 25.5 days; P0.001. Median absorption time and length of hospitalization for all patients was 6 days (IQR 5-8) and 17 days (IQR 13-25), respectively.Radiological findings and clinical characteristics in pregnant women with COVID-19 were similar to those of non-pregnant women with COVID-19. Median absorption time and length of hospitalization in asymptomatic patients were significantly shorter than in symptomatic patients. Lymphocyte percentage and neutrophil granulocyte rate may be used as laboratory indicators of CT absorption.

A new method to reduce the stimulated Raman scattering (SRS) in inertial confinement fusion conditions is proposed by changing the incident light phase discretely. The proposal is first examined by three-wave coupling equations and then verified by Vlasov simulations. A remarkable decreasing in SRS reflectivity is observed when the period of phase changing is less than 2 π / γ , where γ is the growth rate of SRS. By contrast, some simulations with continuously changing phase of incident light are carried out to compare their influence on SRS. In addition, the proposal may suppress the stimulated Brillouin scattering.