Aim To investigate the diagnostic accuracy of dual-source computed tomography (DSCT) coronary angiography with and without the application of a β-blocker. Materials and methods An exact binomial ...rendition of the bivariate mixed-effects regression model was used to synthesize diagnostic test data. Results The pooled sensitivity at the patient level was 0.98 95% confidence intervals (CI): 0.97–0.99, and specificity 0.88 (95% CI: 0.84–0.91). The results showed that without heart rate control, the sensitivity and specificity at the patient level did not decrease ( p = 0.27 and 0.56, respectively). At the artery level, no significant differences in sensitivity and specificity for studies with and without heart rate control were detected ( p = 0.04 and 0.05, respectively). At the segment level, the specificity decreased without heart rate control ( p = 0.03), whereas the sensitivity was not influenced ( p = 0.63). The median radiation exposure was 2.6 mSv, with 1.6 mSv and 8 mSv for heart rate-controlled studies and uncontrolled studies, respectively. Conclusions DSCT coronary angiography without heart rate control has a similar excellent diagnostic performance at the patient level as that of heart rate control groups. However, controlling for heart rate to decrease radiation and to provide effective information for selecting the therapeutic strategy and risk stratification is recommended.
Experimental investigations were conducted on a diesel engine to evaluate the effects of hydrogen addition on engine combustion, unregulated gaseous emissions and particulate emissions based on the ...Japanese 13-mode testing cycle. A diesel–hydrogen co-operated combustion strategy is proposed in which hydrogen is naturally aspirated into the diesel engine to substitute 10, 20 and 30% of the total fuel energy at 10 selected modes and diesel is used as the sole fuel for the other 3 modes. Gradual increase of peak in-cylinder pressure and heat release rate is observed at medium and high engine loads. Pre-ignition might occur at high engine load and speed. Cyclic variation of the indicated mean effective pressure and maximum pressure derivative increased with hydrogen addition. The brake specific emissions of acetaldehyde (CH3CHO), alkenes (C2H4, C3H6 and C4H6), arenes (C6H6, C7H8 and C8H10) and particulate mass can be evidently reduced. However, with H30 operation, the weighted total HC and formaldehyde (HCHO) increased by around 27% and 8%, respectively, while NOx increased by around 17%. The simultaneous decrease of particle size and number are believed to be associated with the inhibition effect of hydrogen on soot particle formation based on the HACA (H2 abstraction and C2H2 addition) mechanism.
•Pre-ignition might occur with ULSD-H2 operation at high engine load and speed.•Hydrogen addition affects the COV of IMEP and Max(dP/dφ).•Most of the unregulated emissions could be effectively reduced with H2 addition.•Effect of H2 on HACA mechanism might result in the reduction of PM, both in size and in number.•Emission performance was evaluated based on the Japanese 13-mode testing cycle for diesel engine.
Nanocrystalline multi-walled carbon nanotube (MWNT)–Sn and MWNT–SnNi composite anode materials were prepared by chemical reduction of SnCl
2 and NiCl
2 precursors in the presence of MWNTs. SEM and ...TEM observations showed that the Sn and SnNi particles are homogeneously dispersed on the MWNT surface and in the MWNT matrix. The electrochemical performance of MWNT–Sn and MWNT–SnNi nanocomposites has been investigated by charge/discharge tests, cyclic voltammetric experiments and the ac impedance technique. The MWNT–Sn and MWNT–SnNi anodes have demonstrated a high first discharge capacity (570 and 512
mA
h/g for MWNT–Sn and MWNT–SnNi anodes, respectively), high charge/discharge efficiency in the first cycle (77.5% and 84.1% for MWNT–Sn and MWNT–SnNi anodes, respectively), and good cyclability (0.99 loss%/cycle for MWNT/SnNi anode). A reaction model has been proposed to explain the reaction mechanisms of lithium insertion and extraction in the MWNT–Sn and MWNT–SnNi electrodes.
Differential cross sections for Compton scattering from the proton have been measured at scattering angles of 55°, 90°, and 125° in the laboratory frame using quasimonoenergetic linearly (circularly) ...polarized photon beams with a weighted mean energy value of 83.4 MeV (81.3 MeV). These measurements were performed at the High Intensity Gamma-Ray Source facility at the Triangle Universities Nuclear Laboratory. The results are compared to previous measurements and are interpreted in the chiral effective field theory framework to extract the electromagnetic dipole polarizabilities of the proton, which gives α_{E1}^{p}=13.8±1.2_{stat}±0.1_{BSR}±0.3_{theo},β_{M1}^{p}=0.2∓1.2_{stat}±0.1_{BSR}∓0.3_{theo} in units of 10^{-4} fm^{3}.
To balance the utilization of rare earth (RE) resource and develop Ce-based permanent magnets with high performance/cost ratio, the role of La substitution in the melt-spun (Ce
1−
x
La
x
)
y
Fe
14
B ...(
x
= 0–0.4, and 0.5;
y
= 2–4) alloys has been investigated. It has been confirmed that the hard magnetic properties of Ce-based magnets can be effectively enhanced by partial substitution of La. The maximum (
BH
)
max
of (Ce,La)–Fe–B alloys can be obtained at a Ce:La atomic ratio of 7:3. The lattice parameters and Curie temperature of the hard magnetic (Ce/La)
2
Fe
14
B phase increase linearly with increasing La content. Three different alloy systems with
y
= 2, 2.5 and 3 show similar behavior of magnetic properties dependences on La. In the RE-rich compositions, La substitution for Ce can effectively inhibit the precipitation of the CeFe
2
phase. A solid solution, Ce(La) phase with a space group of Fm-3m, appears in the (Ce
0.7
La
0.3
)
y
Fe
14
B alloys with
y
≥ 3.5. A good combination of magnetic properties with
H
cj
= 345 kA/m,
J
5T
= 1.03 T,
J
r
= 0.60 T, and (
BH
)
max
= 6.3 MGOe is obtained in (Ce
0.7
La
0.3
)
2.5
Fe
14
B alloy. In addition, 30 at.% La substitution for Ce can significantly refine the grains, resulting in the enhancement of exchange coupling interaction. The present finding is beneficial for designing new and low-cost magnetic materials.
Double Deeply Virtual Compton Scattering (DDVCS) is the only experimental channel for the determination of the dependence of the Generalized Parton Distributions (GPDs) on both the average and the ...transferred momentum independently. The physics observables of the electron induced di-muon production reaction
e
→
±
p
→
e
±
p
μ
+
μ
-
off unpolarized hydrogen are discussed. Their measurement with the high luminosity and large acceptance SoLID spectrometer at the Thomas Jefferson National Accelerator Facility, using polarized and unpolarized positron and electron beams at 11 GeV is investigated. This experimental configuration is shown to provide unprecedented access to the GPDs with the determination of the real and imaginary parts of the Compton Form Factor
H
in an unexplored phase space, and to enable an exploratory investigation of higher twist effects.
Effective and comprehensive evaluation of cold stress is critical for healthy dairy cow breeding in the winter. Previous studies on dairy cow cold stress have considered thermal environmental factors ...but not physiological factors or air quality. Therefore, this study aimed to propose a multilevel fuzzy comprehensive evaluation (FCE) method for cold stress in dairy cows based on the analytic hierarchy process (AHP) and a genetic algorithm (GA). First, the AHP was used to construct an evaluation index system for cold stress in dairy cows from 3 dimensions: thermal environment (temperature, relative humidity, wind speed, and illumination), physiological factors (respiratory rate, body surface temperature), and air quality NH3, CO2, inhalable particulate matter (PM10). Second, the consistency test of the judgment matrix was transformed into a nonlinear constrained optimization problem and solved using the GA. Next, based on fuzzy set theory, the comment set and membership function were established to classify the degree of cold stress into 5 levels: none, mild, moderate, high, and extreme. Then, the degree of cold stress in cows was obtained using multilevel fuzzy comprehensive judgment. To investigate the effect of illumination indicators on cold stress in dairy cows, 24 prelactation cows from the south and north sides were selected for a 117-d comprehensive cold stress evaluation. The results showed that the mean mild cold stress durations were 605.3 h (25.22 d) and 725.5 h (30.23 d) and the moderate cold stress durations were 67.2 h (2.8 d) and 96 h (4.0 d) on the south and north sides, respectively. Simultaneously, generalized linear mixed model showed that there were significant correlations between the daily cold stress duration and milk yield, feeding time, lying time, and active steps in the cows on both sides. This method can reasonably indicate cow cold stress conditions and better guide cold protection practices in actual production.
Abstract G protein–coupled receptor 17 (GPR17), the new P2Y-like receptor, is phylogenetically related to the P2Y and cysteinyl leukotriene receptors, and responds to both uracil nucleotides and ...cysteinyl leukotrienes. GPR17 has been proposed to be a damage sensor in ischemic stroke; however, its role in brain inflammation needs further detailed investigation. Here, we extended previous studies on the spatiotemporal profiles of GPR17 expression and localization, and their implications for brain injury after focal cerebral ischemia. We found that in the ischemic core, GPR17 mRNA and protein levels were upregulated at both 12–24 h and 7–14 days, but in the boundary zone the levels increased 7–14 days after reperfusion. The spatiotemporal pattern of GPR17 expression well matched the acute and late (subacute/chronic) responses in the ischemic brain. According to previous findings, in the acute phase, after ischemia (24 h), upregulated GPR17 was localized in injured neurons in the ischemic core and in a few microglia in the ischemic core and boundary zone. In the late phase (14 days), it was localized in microglia, especially in activated (ED1-positive) microglia in the ischemic core, but weakly in most microglia in the boundary zone. No GPR17 was detectable in astrocytes. GPR17 knockdown by a small interfering RNA attenuated the neurological dysfunction, infarction, and neuron loss at 24 h, and brain atrophy, neuron loss, and microglial activation at 14 days after reperfusion. Thus, GPR17 might mediate acute neuronal injury and late microgliosis after focal cerebral ischemia.
Cancer stem cells (CSCs) are believed to have a crucial role in triple-negative breast cancer (TNBC) recurrence. However, the exact mechanisms that are functionally critical in CSCs-mediated ...recurrence remain unclear. Here, we showed that CSCs derived from recurrent TNBCs are endowed with increased self-renewal capacity as compared with those from the matched primary lesions. Using patient-derived specimens, we demonstrated the existence of paracrine brain-derived neurotrophic factor (BDNF) signaling between differentiated recurrent TNBC cells and CSCs characterized by the expression of TrkB, the receptor of BDNF. We showed that paclitaxel induced BDNF expression and apoptosis simultaneously in a cell cycle-dependent manner. BDNF promotes the self-renewal potential of the TrkB+CSCs through induction of KLF4. The TrkB+CSCs represent a particular subset indispensable for TNBC relapse. In line with this, TrkB is proved to be a superior predictor for TNBC recurrence. Using a genetically engineered mouse model of TNBC, we observed that ablation of the TrkB+CSCs potentially prevents relapse of malignant tumors. Further preclinical investigation of this promising approach may lead to development of a novel therapeutic strategy to improve the devastating prognosis of TNBC patients.
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