Bi-modified Cu-Based Catalysts for Acetylene Hydrogenation: Leveraging Dispersion and Hydrogen Spillover.

Removing trace acetylene from the ethylene stream through selective hydrogenation is a crucial process in the production of polymer-grade ethylene. However, achieving high selectivity while maintaining high activity remains a significant challenge, especially for nonprecious metal catalysts. Herein, the trade-off between activity and selectivity is solved by synergizing enhanced dispersion and hydrogen spillover. Specifically, a bubbling method is proposed for preparing SiO2-supported copper and/or bismuth carbonate with high dispersion, which is then employed to synthesize highly dispersed Bi-modified CuxC-Cu catalyst. The catalyst displays outstanding catalytic performance for acetylene selective hydrogenation, achieving acetylene conversion of 100% and ethylene selectivity of 91.1% at 100 °C. The high activity originates from the enhanced dispersion, and the exceptional selectivity is due to the enhanced spillover capacity of active hydrogen from CuxC to Cu, which is promoted by the Bi addition. The results offer an avenue to design efficient catalysts for selective hydrogenation from nonprecious metals.

Depth estimation for broadband sources with a vertical line array in deep water.

In deep water, deploying a short vertical line array (VLA) is an effective way for source localization. In the past decade, most studies focused on localizing sources at the short to moderate ranges in the reliable acoustic path or the direct arrival zone (DAZ), with a VLA deployed near the ocean bottom. Little work has been done for the end part of the DAZ and the zones outside the DAZ. In addition, a VLA deployed at other depths rather than near the bottom is rarely studied. This paper proposes a near-surface source depth estimation method by matching the measured time delay with a library of modeled values under different source depths calculated by a simple formula. This method is suitable for zones, which contains two paths (one is reflected from the sea surface) with very close arrival angles, of a VLA deployed not only near the bottom, but also at other depths of the water column. Source depth estimation strategy for the end part of each zone, which faces the problem of poor depth resolution, is also analyzed. Simulation and experimental data of the airgun and explosive sources in the South China Sea are used to demonstrate the method.

Protective effect of San Huang Pill and its bioactive compounds against ulcerative colitis in Drosophila via modulation of JAK/STAT, apoptosis, Toll, and Nrf2/Keap1 pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: San Huang Pill (SHP) is a prescription in Dunhuang Ancient Medical Prescription, which has the efficacy of heat-clearing and dampness-drying, and is a traditional formula for the treatment of gastrointestinal diseases. However, its efficacy and mechanism in treating ulcerative colitis (UC) are still unclear. AIM OF THE STUDY: To investigate the protective effects of SHP and its bioactive compounds against Dextran Sulfate Sodium (DSS)-induced intestinal damage using the Drosophila melanogaster model, and to detect the molecular mechanism of SHP in the treatment of UC. METHODS: Survival rate, locomotion, feeding, and excretion were used to explore the anti-inflammatory effects of SHP. The pharmacotoxicity of SHP was measured using developmental analysis. Intestinal integrity, intestinal length, intestinal acid-base homeostasis, and Tepan blue assay were used to analyze the protective effect of SHP against DSS-induced intestinal damage. The molecular mechanism of SHP was detected using DHE staining, immunofluorescence, real-time PCR, 16 S rRNA gene sequencing, and network pharmacology analysis. Survival rate, intestinal length, and integrity analysis were used to detect the protective effect of bioactive compounds of SHP against intestinal damage. RESULTS: SHP supplementation significantly increased the survival rate, restored locomotion, increased metabolic rate, maintained intestinal morphological integrity and intestinal homeostasis, protected intestinal epithelial cells, and alleviated intestinal oxidative damage in adult flies under DSS stimulation. Besides, administration of SHP had no toxic effect on flies. Moreover, SHP supplementation remarkably decreased the expression levels of genes related to JAK/STAT, apoptosis, and Toll signaling pathways, increased the gene expressions of the Nrf2/Keap1 pathway, and also reduced the relative abundance of harmful bacteria in DSS-treated flies. Additionally, the ingredients in SHP (palmatine, berberine, baicalein, wogonin, rhein, and aloeemodin) had protection against DSS-induced intestinal injury, such as prolonging survival rate, increasing intestinal length, and maintaining intestinal barrier integrity. CONCLUSION: SHP had a strong anti-inflammatory function, and remarkably alleviated DSS-induced intestinal morphological damage and intestinal homeostatic imbalance in adult flies by regulating JAK/STAT, apoptosis, Toll and Nrf2/Keap1 signaling pathways, and also gut microbial homeostasis. This suggests that SHP may be a potential complementary and alternative medicine herb therapy for UC, which provides a basis for modern pharmacodynamic evaluation of other prescriptions in Dunhuang ancient medical prescription.

Performance comparison of conventional and striation-based beamformers for underwater bearing detection of pulse sources.

The multi-path and dispersion properties of shallow water waveguides make conventional beamforming (CBF) face issues such as beam shift, broadening, splitting, output distortion, and array gain reduction. In this paper, the striation-based beamforming (SBF) is investigated to address these issues. SBF differs from CBF by utilizing frequency-shift processing along interference striations. The performance difference between CBF and SBF is compared. It demonstrates that under ideal waveguide modeling with pulse sources, SBF can achieve a beam output response that is close to the plane wave condition. The speed term of SBF's response is approximately independent of modal indexes, which equips SBF to form a unique beam output and guarantee the beam resolution. The processing of consistent signals along the striation maintains the optimal signal correlation, which makes SBF ensure the output fidelity and array gain. To shift the mainlobe of SBF to the source azimuth, the time delay related to the waveform truncation point can be introduced to pre-compensate the array signals. There exist two theoretical accuracy limits to using the truncation. First, truncation time corresponds to the waveform point at r0/c (r0 is the source range), and the mainlobe of SBF is directed to the source azimuth. Second, truncation corresponds to the pulse peak point, and the azimuth estimation accuracy of SBF gets close to CBF. Simulations and experimental results are given as illustrations.

Sources depth estimation for a tonal source by matching the interference structure in the arrival angle domain.

A publication by McCargar and Zurk [J. Acoust. Soc. Am. 133(4), EL320-EL325 (2013)] introduced a passive source depth estimation method for a moving tonal source with a vertical line array (VLA), utilizing the depth-dependent modulation in the arrival angle domain caused by the interference between the direct and surface-reflected acoustic arrivals. Under the isovelocity approximation, this method can estimate the depth of sources at close ranges, but the depth estimation error will increase with the increase in source range, as the impact of the sound speed profile on sound propagation is ignored. This paper presents a theoretical formula for calculating the modeled interference structure in the arrival angle domain with the knowledge of the sound speed profile. By matching the measured interference structure obtained from the beamforming of the acoustic data received by the VLA with the modeled structure under different assumed source depths, the tonal source depth estimation is achieved, even for sources at the remote part of the direct arrival zone. The performance of this method is verified by simulation data, as well as experimental data radiated from a towed source and a non-cooperative passing ship.

Passive source localization based on multipath arrival angles with a vertical line array using sparse Bayesian learning.

In deep water, multipath time delays or frequency-domain interference periods of the acoustic intensity combined with multipath arrival angles are typically used for source localization. However, depth estimate is hard to achieve for a narrowband source at a remote part of the direct arrival zone as the required bandwidth increases with the source range. In this paper, a passive source localization method with a vertical line array, suitable for both broadband and narrowband sources, is proposed. Based on the variation trends of multipath angles with source range and depth, source localization is achieved by only matching the measured angles of the direct path and surface-reflected path with model-based values of a predefined grid of potential source locations. Considering the angle resolution limited by the array aperture and the presence of coherent multipath, sparse Bayesian learning is used and compared with the conventional beamforming and the minimum-variance distortionless-response beamforming to resolve and estimate the multipath angles. Simulations and experimental data of explosive sources collected by a vertical line array in the South China Sea are carried out to illustrate the method and demonstrate the performance.

A Novel Near-Infrared Ytterbium Complex [Yb(DPPDA)2](DIPEA) with Φ = 0.46% and τobs = 105 µs.

The luminescent performances of near-infrared (NIR) lanthanide (Ln) complexes were restricted greatly by vibration quenching of X-H (X = C, N, O) oscillators, which are usually contained in ligands and solvents. Encapsulating Ln3+ into a cavity of coordination atoms is a feasible method of alleviating this quenching effect. In this work, a novel ytterbium complex [Yb(DPPDA)2](DIPEA) coordinated with 4,7-diphenyl-1,10-phenanthroline-2,9-dicarboxylic acid (DPPDA) was synthesized and characterized by FT-IR, ESI-MS and elemental analysis. Under the excitation of 335 nm light, [Yb(DPPDA)2](DIPEA) showed two emission peaks at 975 and 1011 nm, respectively, which were assigned to the characteristic 2F5/2 → 2F7/2 transition of Yb3+. Meanwhile, this ytterbium complex exhibited a plausible absolute quantum yield of 0.46% and a luminescent lifetime of 105 µs in CD3OD solution. In particular, its intrinsic quantum yield was calculated to be 12.5%, and this considerably high value was attributed to the near-zero solvent molecules bound to Yb3+ and the absence of X-H oscillators in the first coordination sphere. Based on experimental results, we further proposed that the sensitized luminescence of [Yb(DPPDA)2](DIPEA) occurred via an internal redox mechanism instead of an energy transfer process.

PET-based radiomics visualizes tumor-infiltrating CD8 T cell exhaustion to optimize radiotherapy/immunotherapy combination in mouse models of lung cancer.

BACKGROUND: Cumulative preclinical and clinical evidences showed radiotherapy might augment systemic antitumoral responses to immunotherapy for metastatic non-small cell lung cancer, but the optimal timing of combination is still unclear. The overall infiltration and exhausted subpopulations of tumor-infiltrating CD8+ T cells might be a potential biomarker indicating the response to immune checkpoint inhibitors (ICI), the alteration of which is previously uncharacterized during peri-irradiation period, while dynamic monitoring is unavailable via repeated biopsies in clinical practice. METHODS: Basing on tumor-bearing mice model, we investigated the dynamics of overall infiltration and exhausted subpopulations of CD8+ T cells after ablative irradiation. With the understanding of distinct metabolic characteristics accompanied with T cell exhaustion, we developed a PET radiomics approach to identify and visualize T cell exhaustion status. RESULTS: CD8+ T cell infiltration increased from 3 to 14 days after ablative irradiation while terminally exhausted populations significantly predominated CD8+ T cells during late course of this infiltrating period, indicating that 3-7 days post-irradiation might be a potential appropriate window for delivering ICI treatment. A PET radiomics approach was established to differentiate T cell exhaustion status, which fitted well in both ICI and irradiation settings. We also visualized the underlying association of more heterogeneous texture on PET images with progressed T cell exhaustion. CONCLUSIONS: We proposed a non-invasive imaging predictor which accurately assessed heterogeneous T cell exhaustion status relevant to ICI treatment and irradiation, and might serve as a promising solution to timely estimate immune-responsiveness of tumor microenvironment and the optimal timing of combined therapy.

An efficient NiCu@C/Al2O3 catalyst for selective hydrogenation of acetylene.

The development of non-noble metal catalysts for selective hydrogenation still remains a challenge. Herein, NiCu@carbon core-shell nanoparticles supported on Al2O3 (NiCu@C/Al2O3) were prepared, which showed enhanced catalytic performance of acetylene-selective hydrogenation in comparison with NiCu/Al2O3 without carbon encapsulation. In detail, NiCu@C/Al2O3 displayed high ethylene selectivity (>86%) even at an acetylene conversion of 100% and excellent stability (>90 h). Thus, NiCu@C/Al2O3 exhibited great potential as an alternative to Pd-based catalysts for acetylene-selective hydrogenation.

Preoperative Changes of Lung Nodule on Computed Tomography and Their Relationship With Pathological Outcomes.

Background: Whether changes of lung nodules on computed tomography could bring us helpful information related to their pathological outcomes remained unclear. Materials and Methods: This retrospective study was carried out among 1,185 cases of lung nodules in Shanghai Chest Hospital from January 2015 to April 2017, which did not shrink or disappear after preoperative follow-up over three months. Their imaging features, changes, and clinical characteristics were collected. A separate analysis was performed in nodules with or without growth in long-axis diameter after follow-up, searching significant changes related to nodule malignancy and the median interval of follow-up for reference. Further study was performed similarly in malignant nodules for discrimination of malignant grading. Results: Most nodules were stable (n = 885, 75%), whereas others grew (n = 300, 25%). For predicting nodule malignancy, increase in density (>10 Hounsfield units, median follow-up of 549 days) played an important role in growing group whereas it failed in stable group, and the increase in size was less significant in growing group. For discrimination of malignant grading, increase in density (>70 Hounsfield units, median follow-up of 366 days) showed its significance in stable group, and so did increase in size in growing group (maximum diameter growth >3.3 mm, median follow-up of 549 days, or average diameter growth >3.1 mm, median follow-up of 625 days). Conclusions: There were significant changes of lung nodules by follow-up on computed tomography, related to their pathological outcomes. The predictive power of increase in density or size varied in different situations, whereas all referred to a long-time preoperative follow-up.

One-Step Green Solvothermal Synthesis of Full-Color Carbon Quantum Dots Based on a Doping Strategy.

Proposing a simple strategy for developing full-color carbon quantum dots (CQDs) and exploring how the luminescence can be tuned and improved is attractive and encouraging. Herein, blue, green, yellow-green, and orange-red CQDs doped with heteroatoms were synthesized in one pot and separated by column chromatography, with emission peaks of 435 nm, 495 nm [photoluminescence quantum yield (PLQY) of 88.9%], 525 nm, and 595 nm (full width at half-maximum of 31 nm), respectively. The abundant C-O/C-O-C electron donor groups greatly improve the PLQY of green CQDs, and the expended effective conjugated domains (particle size, doped chlorine, and conjugated nitrogen) of CQDs boost the red-shifts of emission spectra. Energy transfer (ET) in a concentrated mixed solution of CQDs was discovered, and possible ET mechanisms are proposed. Furthermore, a high-efficiency white light-emitting diode with Commission Internationale de L'Eclairage coordinates of (0.361, 0.369), a correlated color temperature of 4534 K, and a high color rendering index of 90.8 was fabricated.

A clinically practical radiomics-clinical combined model based on PET/CT data and nomogram predicts EGFR mutation in lung adenocarcinoma.

OBJECTIVES: This study aims to develop a clinically practical model to predict EGFR mutation in lung adenocarcinoma patients according to radiomics signatures based on PET/CT and clinical risk factors. METHODS: This retrospective study included 583 lung adenocarcinoma patients, including 295 (50.60%) patients with EGFR mutation and 288 (49.40%) patients without EGFR mutation. The clinical risk factors associated with lung adenocarcinoma were collected at the same time. We developed PET/CT, CT, and PET radiomics models for the prediction of EGFR mutation using multivariate logistic regression analysis, respectively. We also constructed a combined PET/CT radiomics-clinical model by nomogram analysis. The diagnostic performance and clinical net benefit of this risk-scoring model were examined via receiver operating characteristic (ROC) curve analysis while the clinical usefulness of this model was evaluated by decision curve analysis (DCA). RESULTS: The ROC analysis showed predictive performance for the PET/CT radiomics model (AUC = 0.76), better than the PET model (AUC = 0.71, Delong test: Z = 3.03, p value = 0.002) and the CT model (AUC = 0.74, Delong test: Z = 1.66, p value = 0.098). Also, the PET/CT radiomics-clinical combined model has a better performance (AUC = 0.84) to predict EGFR mutation than the PET/CT radiomics model (AUC = 0.76, Delong test: D = 2.70, df = 790.81, p value < 0.001) or the clinical model (AUC = 0.81, Delong test: Z = 3.46, p value < 0.001). CONCLUSIONS: We demonstrated that the combined PET/CT radiomics-clinical model has an advantage to predict EGFR mutation in lung adenocarcinoma. KEY POINTS: • Radiomics from lung tumor increase the efficiency of the prediction for EGFR mutation in clinical lung adenocarcinoma on PET/CT. • A radiomic nomogram was developed to predict EGFR mutation. • Combining PET/CT radiomics-clinical model has an advantage to predict EGFR mutation.

Anomalous dispersion observed in signal arrivals at a deep-sea floor receiver.

An anomalous dispersion, e.g., when low frequencies arrive earlier whereas the high frequencies arrive later, was observed in the signal arrivals recorded by a single deep-sea bottom-mounted vector sensor. Numerical simulations and modal analyses, based on a three-layer range-independent model, are applied to interpret the anomalous dispersion. Results indicate that the arrival with anomalous dispersion corresponds to trapped modes in the low sound speed sediment and can be observed when both the source and receiver are deployed near the seafloor. Furthermore, the cutoff frequencies, dispersion characteristics, and energy distributions of trapped modes are also performed in this paper.

Observation and inversion of very-low-frequency seismo-acoustic fields in the South China Sea.

Very-low-frequency (VLF) sound has significant potential for underwater detection and estimation of geoacoustic models of the ocean bottom structure. In marine settings, one type of VLF sound is the interface wave. These waves, trapped near the fluid-solid interface, are called Scholte waves, and this is the subject of this study. A field experiment was carried out in the South China Sea with the objective of exciting Scholte waves and investigating the propagation. The data were acquired by an ocean bottom seismometer, deployed on the seafloor. A large volume airgun array near the sea surface provided the sound source. The fundamental and three higher-order mode Scholte waves were excited. The Scholte waves are investigated by seismograms and a phase velocity inversion. The observed frequencies are in the range of 1.0-2.9 Hz. The energy attenuation is proportional to 1/r at the peak frequency 1.4 Hz. The shear wave speed structure, down to 600 m beneath the seafloor, is revealed from the dispersion curves by a least-squares inversion algorithm. The inversion result shows that the shear wave speed is below 300 m/s in the uppermost layer, which explains well the weak excitation of Scholte waves in this experiment.

Passive broadband source depth estimation in the deep ocean using a single vector sensor.

For an acoustic receiver deployed at the bottom of the direct arrival zone of a submerged source at short horizontal ranges in deep ocean, the interference pattern of the direct and surface-reflected acoustic arrivals shows periodic modulation, which is directly related to the source depth, source frequency, and vertical arrival angle. In this work, the interference cycle presented in the frequency domain is used to extract the broadband source depth, with the vertical arrival angle obtained from the ratio of vertical acoustic intensity and horizontal acoustic intensity from the signal recorded by a single vector sensor. Experimental results demonstrate the source depth estimation without requiring knowledge of the ocean environment.

Closed-Loop Attention Restoration Theory for Virtual Reality-Based Attentional Engagement Enhancement.

Today, as media and technology multitasking becomes pervasive, the majority of young people face a challenge regarding their attentional engagement (that is, how well their attention can be maintained). While various approaches to improve attentional engagement exist, it is difficult to produce an effect in younger people, due to the inadequate attraction of these approaches themselves. Here, we show that a single 30-min engagement with an attention restoration theory (ART)-inspired closed-loop software program (Virtual ART) delivered on a consumer-friendly virtual reality head-mounted display (VR-HMD) could lead to improvements in both general attention level and the depth of engagement in young university students. These improvements were associated with positive changes in both behavioral (response time and response time variability) and key electroencephalography (EEG)-based neural metrics (frontal midline theta inter-trial coherence and parietal event-related potential P3b). All the results were based on the comparison of the standard Virtual ART tasks (control group, n = 15) and closed-loop Virtual ART tasks (treatment group, n = 15). This study provides the first case of EEG evidence of a VR-HMD-based closed-loop ART intervention generating enhanced attentional engagement.

Bonding characteristics, thermal expansibility, and compressibility of RXO(4) (R = rare earths, X = P, As) within monazite and zircon structures.

Systematically theoretical research was performed on the monazite- and zircon-structure RXO(4) (R = Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu; X = P, As) series by using the chemical bond theory of dielectric description. The chemical bond properties of R-O and X-O bonds were presented. In the zircon phase, the covalency fractions of X-O bonds increased in the order of V-O < As-O < P-O, which was in accordance with the ionic radii and electronegative trends, and the covalency fractions of R-O bonds varied slightly due to the lanthanide contraction. While in the monazite phase, both R-O and X-O bonds were divided into two groups by their covalency fractions. The contributions from the bond to the lattice energy, linear thermal expansion coefficient (LTEC), and bulk modulus were explored. The X-O bonds with short bond lengths and high chemical valence made greater contributions to the lattice energy and performed nearly rigidly during the deformation. A regular variation of lattice energy, LTEC, and bulk modulus with the ionic radii of the lanthanides was observed in both monazite and zircon phases.

Investigation of chemical bond characteristics, thermal expansion coefficients and bulk moduli of alpha-R2MoO6 and R2Mo2O7 (R = rare earths) by using a dielectric chemical bond method.

Theoretical researches are performed on the alpha-R2MoO6 (R = Y, Gd, Tb Dy, Ho, Er, Tm and Yb) and pyrochlore-type R2Mo2O7 (R = Y, Nd, Sm, Gd, Tb and Dy) rare earth molybdates by using chemical bond theory of dielectric description. The chemical bonding characteristics and their relationship with thermal expansion property and compressibility are explored. The calculated values of linear thermal expansion coefficient (LTEC) and bulk modulus agree well with the available experimental values. The calculations reveal that the LTECs and the bulk moduli do have linear relationship with the ionic radii of the lanthanides: the LTEC decreases from 6.80 to 6.62 10(-6)/K and the bulk modulus increases from 141 to 154 GPa when R goes in the order Gd, Tb Dy, Ho, Er, Tm, and Yb in the alpha-R2MoO6 series; while in the R2Mo2O7 series, the LTEC ranges from 6.80 to 6.61 10(-6)/K and the bulk modulus ranges from 147 to 163 GPa when R varies in the order Nd, Sm, Gd, Tb and Dy.

Investigation of thermal expansion and compressibility of rare-earth orthovanadates using a dielectric chemical bond method.

The chemical bond properties, lattice energies, linear expansion coefficients, and mechanical properties of ReVO 4 (Re = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc, Y) are investigated systematically by the dielectric chemical bond theory. The calculated results show that the covalencies of Re-O bonds are increasing slightly from La to Lu and that the covalencies of V-O bonds in crystals are decreasing slightly from La to Lu. The linear expansion coefficients decrease progressively from LaVO 4 to LuVO 4; on the contrary, the bulk moduli increase progressively. Our calculated results are in good agreement with some experimental values for linear expansion coefficients and bulk moduli.

Calculation of the bulk modulus of simple and complex crystals with the chemical bond method.

The relation between the lattice energies and the bulk moduli on binary inorganic crystals was studied, and the concept of lattice energy density is introduced. We find that the lattice energy densities are in good linear relation with the bulk moduli in the same type of crystals, the slopes of fitting lines for various types of crystals are related to the valence and coordination number of cations of crystals, and the empirical expression of calculated slope is obtained. From crystal structure, the calculated results are in very good agreement with the experimental values. At the same time, by means of the dielectric theory of the chemical bond and the calculating method of the lattice energy of complex crystals, the estimative method of the bulk modulus of complex crystals was established reasonably, and the calculated results are in very good agreement with the experimental values.