From 2D to 3D: Automatic measurement of the Cobb angle in adolescent idiopathic scoliosis with the weight-bearing 3D imaging.

BACKGROUND CONTEXT: Adolescent idiopathic scoliosis (AIS) necessitates accurate spinal curvature assessment for effective clinical management. Traditional two-dimensional (2D) Cobb angle measurements have been the standard, but the emergence of three-dimensional (3D) automatic measurement techniques, such as those using weight-bearing 3D imaging (WR3D), presents an opportunity to enhance the accuracy and comprehensiveness of AIS evaluation. PURPOSE: This study aimed to compare traditional 2D Cobb angle measurements with 3D automatic measurements utilizing the WR3D imaging technique in patients with AIS. STUDY DESIGN/SETTING: A cohort of 53 AIS patients was recruited, encompassing 88 spinal curves, for comparative analysis. PATIENT SAMPLE: The patient sample consisted of 53 individuals diagnosed with AIS. OUTCOME MEASURES: Cobb angles were calculated using the conventional 2D method and three different 3D methods: the Analytical Method (AM), the Plane Intersecting Method (PIM), and the Plane Projection Method (PPM). METHODS: The 2D cobb angle was manually measured by 3 experienced clinicians with 2D frontal whole-spine radiographs. For 3D cobb angle measurements, the spine and femoral heads were segmented from the WR3D images using a 3D-UNet deep-learning model, and the automatic calculations of the angles were performed with the 3D slicer software. RESULTS: AM and PIM estimates were found to be significantly larger than 2D measurements. Conversely, PPM results showed no statistical difference compared to the 2D method. These findings were consistent in a subgroup analysis based on 2D Cobb angles. CONCLUSION: Each 3D measurement method provides a unique assessment of spinal curvature, with PPM offering values closely resembling 2D measurements, while AM and PIM yield larger estimations. The utilization of WR3D technology alongside deep learning segmentation ensures accuracy and efficiency in comparative analyses. However, additional studies, particularly involving patients with severe curves, are required to validate and expand on these results. This study emphasizes the importance of selecting an appropriate measurement method considering the imaging modality and clinical context when assessing AIS, and it also underlines the need for continuous refinement of these techniques for optimal use in clinical decision-making and patient management.

Phase-Dependent Magnetic Proximity Modulations on Valley Polarization and Splitting.

Proximate-induced magnetic interactions present a promising strategy for precise manipulation of valley degrees of freedom. Taking advantage of the splendid valleytronic platform of transition metal dichalcogenides, magnetic two-dimensional VSe2 with different phases are introduced to intervene in the spin of electrons and modulate their valleytronic properties. When constructing the heterostructures, 1T-VSe2/WX2 (X = S and Se) showcases significant improvement in the valley polarizations at room temperature, while 2H-VSe2/WX2 exhibits superior performance at low temperatures and demonstrates heightened sensitivity to the external magnetic field. Simultaneously, considerable valley splitting with a large geff factor up to -29.0 is observed in 2H-VSe2/WS2, while it is negligible in 1T-VSe2/WX2. First-principles calculations reveal a phase-dependent magnetic proximity mechanism on the valleytronic modulations, which is dominated by interfacial charge transfer in 1T-VSe2/WX2 and the proximity exchange field in 2H-VSe2/WX2 heterostructures. The effective control over valley degrees of freedom will bridge the valleytronic physics and devices, rendering enormous potential in the field of valley quantum applications.

Safety of non-ionic contrast media in CT examinations for out-patients: retrospective multicenter analysis of 473,482 patients.

OBJECTIVES: This study aimed to explore the incidence of and potential risk factors for adverse drug reactions (ADRs) after non-ionic iodinated contrast media (NICM) administration for CT exams in out-patient settings in China. MATERIALS AND METHODS: A total of 473,482 out-patients who underwent intravenous NICM between January 1st, 2017, and Dec 31st, 2021, were retrospectively enrolled from three institutions. The occurrence of ADRs and clinical information were recorded. Chi-square test, Poisson regression, and logistic regression analyses were used to evaluate potential ADR risk factors and correlation with demographics, season, and NICM type. RESULTS: Among the 473,482 patients (mean age 55.22 ± 14.85; 253,499 male) who received intravenous NICM, the overall ADR incidence was 0.110% (522 of 473,482), with 0.099% acute-related drug reactions (469 of 473,482) and 0.0004% serious ADRs (two of 473,482). Iopromide was associated with a higher risk of acute ADRs. Late ADRs were more frequently observed with iodixanol 320. Multi-level logistic regression of patients with acute ADRs and a control group (matched 1:1 for age, gender, NICM, prescriber department, and institution) showed that summer (adjusted OR = 1.579; p = 0.035) and autumn (adjusted OR = 1.925; p < 0.001) were risk factors of acute ADRs. However, underlying disease and scanned body area were not related to a higher ADR incidence. CONCLUSION: The use of NICM for out-patients is in general safe with a low ADR incidence. The type of contrast medium (iopromide) and the seasons (summer and autumn) were associated with a higher risk of acute ADRs. Late ADRs were more often observed with iodixanol. CLINICAL RELEVANCE STATEMENT: In comparison to in-patients, out-patients may be exposed to higher risk due to a lack of extensive risk screening, less nursing care, and higher throughput pressure. Safety data about NICM from a large population may complement guidelines and avoid ambiguity. KEY POINTS: • The incidence and risk factors for adverse events after using non-ionic iodinated contrast media are complex in out-patients. • Non-ionic iodinated contrast media are safe for out-patients and the overall incidence of adverse drug reactions was 0.110%. • There is a higher risk of acute adverse drug reactions in summer and autumn.

Imaging-based deep learning in kidney diseases: recent progress and future prospects.

Kidney diseases result from various causes, which can generally be divided into neoplastic and non-neoplastic diseases. Deep learning based on medical imaging is an established methodology for further data mining and an evolving field of expertise, which provides the possibility for precise management of kidney diseases. Recently, imaging-based deep learning has been widely applied to many clinical scenarios of kidney diseases including organ segmentation, lesion detection, differential diagnosis, surgical planning, and prognosis prediction, which can provide support for disease diagnosis and management. In this review, we will introduce the basic methodology of imaging-based deep learning and its recent clinical applications in neoplastic and non-neoplastic kidney diseases. Additionally, we further discuss its current challenges and future prospects and conclude that achieving data balance, addressing heterogeneity, and managing data size remain challenges for imaging-based deep learning. Meanwhile, the interpretability of algorithms, ethical risks, and barriers of bias assessment are also issues that require consideration in future development. We hope to provide urologists, nephrologists, and radiologists with clear ideas about imaging-based deep learning and reveal its great potential in clinical practice.Critical relevance statement The wide clinical applications of imaging-based deep learning in kidney diseases can help doctors to diagnose, treat, and manage patients with neoplastic or non-neoplastic renal diseases.Key points• Imaging-based deep learning is widely applied to neoplastic and non-neoplastic renal diseases.• Imaging-based deep learning improves the accuracy of the delineation, diagnosis, and evaluation of kidney diseases.• The small dataset, various lesion sizes, and so on are still challenges for deep learning.

Clinical Applications and Recent Updates of Simultaneous Multi-slice Technique in Accelerated MRI.

Simultaneous multi-slice (SMS) is a magnetic resonance imaging (MRI) acceleration technique that utilizes multi-band radio-frequency pulses to simultaneously excite and encode multiple slices. Currently, SMS has been widely studied and applied in the MRI examination to reduce acquisition time, which can significantly improve the examination efficiency and patient throughput. Moreover, SMS technique can improve spatial resolution, which is of great value in disease diagnosis, treatment response monitoring, and prognosis prediction. This review will briefly introduce the technical principles of SMS, and summarize its current clinical applications. More importantly, we will discuss the recent technical progress and future research direction of SMS, hoping to highlight the clinical value and scientific potential of this technique.

Assessment of Outer Retina and Choroid Using Swept Source Optical Coherence Tomography and Angiography in Patients With Multiple Sclerosis.

BACKGROUND: For patients with multiple sclerosis (MS), both structure and microvasculature alterations in the inner retina have been investigated in several studies. However, little is known about the alterations in the outer retina and choroid. Hence, this study aimed to assess the outer retinal and choroidal changes in patients with MS with no history of optic neuritis (ON). METHODS: Patients with MS and healthy control participants were enrolled in this cross-sectional study. Quantitative analyses were performed using swept source optical coherence tomography and swept source optical coherence tomography angiography images to assess outer retina thickness (ORT) and choroid thickness (CT), vessel density (VD) of choriocapillaris, and choroidal vascularity index (CVI), which were then compared between the groups. RESULTS: A total of 37 participants with MS (72 eyes) and 74 healthy control participants (148 eyes) were included in this study. Compared with healthy controls, patients with MS with no history of ON showed reduced VD of the choriocapillaris and CVI. There was no significant difference in ORT and CT between 2 groups. Meanwhile, in patients with MS, no correlation between OCTA parameters and expanded disability status scale score were found in this study. CONCLUSIONS: Our study indicates that patients with MS with no history of optical neuritis have reduced choriocapillaris vessel density and decreased choroidal vascularity index without detectable alteration in outer retina thickness and choroid thickness. The findings complement the outer retinal and choroidal component of MS, providing deeper insight into the pathophysiology of MS.

Weight-bearing cone-beam CT with extensive coverage for volumetric imaging in adolescent idiopathic scoliosis: system implementation and initial validation.

The study aimed to introduce a novel imaging method that generates large-coverage, weight-bearing, and 3D images of the whole spine. The proposed system comprises an X-ray tube, a flat panel detector, and a standing platform. The standing platform rotates the imaged subject, allowing for the acquisition of serial fluoroscopic images from different angles which can be used to create 3D images. To increase the longitudinal coverage, we apply a segmental scanning pattern in which the imaged region is scanned in segments and stitched. To address the issue of data inaccuracy between the segments, redundant areas are set at margins of the segmental images, and registration and stitching algorithms are applied. We conducted validation experiments to evaluate radiation dose and image quality. The dose was evaluated using the volume CT dose index (CTDIvol). For image quality evaluation, we measured the low-contrast and spatial resolution. Additionally, we conducted a clinical study consisting of 30 volunteers with adolescent idiopathic scoliosis who were imaged by our method, and the images were subjectively assessed based on image noise, artifacts, anatomical coverage, diagnostic confidence, and overall quality. The CTDIvol was 1.23 mGy, and the low-contrast resolution was 0.6% at 4 mm and the spatial resolution was 8 lp/cm. The clinical images were generally of good quality, with high scores for all factors evaluated. Our method successfully generates large-coverage, weight-bearing, and 3D images of the whole spine with high image quality and low radiation dose. It shows potential for wider clinical applications for various musculoskeletal conditions.

A Solid-State Source of Single and Entangled Photons at Diamond SiV-Center Transitions Operating at 80K.

Large-scale quantum networks require the implementation of long-lived quantum memories as stationary nodes interacting with qubits of light. Epitaxially grown quantum dots hold great potential for the on-demand generation of single and entangled photons with high purity and indistinguishability. Coupling these emitters to memories with long coherence times enables the development of hybrid nanophotonic devices that incorporate the advantages of both systems. Here we report the first GaAs/AlGaAs quantum dots grown by the droplet etching and nanohole infilling method, emitting single photons with a narrow wavelength distribution (736.2 ± 1.7 nm) close to the zero-phonon line of silicon-vacancy centers. Polarization entangled photons are generated via the biexciton-exciton cascade with a fidelity of (0.73 ± 0.09). High single photon purity is maintained from 4 K (g(2)(0) = 0.07 ± 0.02) up to 80 K (g(2)(0) = 0.11 ± 0.01), therefore making this hybrid system technologically attractive for real-world quantum photonic applications.

Characteristic CT angiography findings and clinical value of catheter-related central venous thrombosis in hemodialysis patients with end-stage renal disease.

BACKGROUND: Central catheter-related thrombosis (CRT) is the most common catheter-related complication in patients with end-stage renal disease (ESRD) but is often underappreciated and misdiagnosed by radiologist. PURPOSE: To find the computed tomography angiography (CTA) characteristics of central CRT, then raise the diagnosis of this disorder. MATERIAL AND METHODS: A total of 301 eligible patients with ESRD who experienced both chest multi-phase multidetector CTA (MDCTA) and digital subtraction angiography were enrolled in the final analysis. The location, shape, and related signs of the central CRT in MDCTA images were evaluated. Independent-samples T test, chi-square test, and binary logistic regression were analyzed using SPSS software. RESULTS: In total, 166 patients were found to have CRT using MDCTA, and this was verified by DSA. Central CRT was usually irregular in the superior vena cava segment, and the angle of the contact area between central CRT and catheter was <180° (all P < 0.05). Age, collateral circulation, and venous stenosis were shown to have significant differences when compared to patients without CRT (all P < 0.05), but there were no significant differences about the sex or catheter insertion site. In addition, age and collateral circulation were the factors found to be significantly associated with thrombosis (P < 0.05). In particular, the thrombosis was 2.213 times more likely to be found in those patients with collateral circulation (odds ratio = 2.213, 95% confidence interval = 1.236-3.961). CONCLUSION: Chest multi-phase MDCTA can effectively reduce the missed diagnosis and misdiagnosis of central CRT. It is worth paying more attention to the central CRT especially when the collateral circulation is observed.

Effects of Multi-Walled Carbon Nanotubes and Nano-Silica on Root Development, Leaf Photosynthesis, Active Oxygen and Nitrogen Metabolism in Maize.

Carbon nanotubes (MWCNTs) and nano-silica (nano-SiO2) are widely used in the field of life science because of their special physical and chemical properties. In this study, the effects of different concentrations of MWCNTs (0 mg·L-1, 200 mg·L-1, 400 mg·L-1, 800 mg·L-1 and 1200 mg·L-1) and nano-SiO2 (0 mg·L-1, 150 mg·L-1, 800 mg·L-1, 1500 mg·L-1 and 2500 mg·L-1) on maize seedling growth and relative mechanisms were explored. The main results are as follows: MWCNTs and nano-SiO2 can promote the growth of maize seedlings, and promote plant height, root length, the dry and fresh weight of seedlings, root-shoot ratio and so on. The ability to accumulate dry matter increased, the relative water content of leaves increased, the electrical conductivity of leaves decreased, the stability of cell membranes improved and the water metabolism ability of maize seedlings increased. The treatment of MWCNTs with 800 mg·L-1 and nano-SiO2 with 1500 mg·L-1 had the best effect on seedling growth. MWCNTs and nano-SiO2 can promote the development of root morphology, increase root length, root surface area, average diameter, root volume and total root tip number and improve root activity, so as to improve the absorption capacity of roots to water and nutrition. After MWCNT and nano-SiO2 treatment, compared with the control, the contents of O2·- and H2O2 decreased, and the damage of reactive oxygen free radicals to cells decreased. MWCNTs and nano-SiO2 can promote the clearance of reactive oxygen species and maintain the complete structure of cells, so as to slow down plant aging. The promoting effect of MWCNTs treated with 800 mg·L-1 and nano-SiO2 treated with 1500 mg·L-1 had the best effect. After treatment with MWCNTs and nano-SiO2, the activities of key photosynthesis enzymes PEPC, Rubisco, NADP-ME, NADP-MDH and PPDK of maize seedlings increased, which promoted the opening of stomata, improved the fixation efficiency of CO2, improved the photosynthetic process of maize plants and promoted plant growth. The promoting effect was the best when the concentration of MWCNTs was 800 mg·L-1 and the concentration of nano-SiO2 was 1500 mg·L-1. MWCNTs and nano-SiO2 can increase the activities of the enzymes GS, GOGAT, GAD and GDH related to nitrogen metabolism in maize leaves and roots, and can increase the content of pyruvate, so as to promote the synthesis of carbohydrates and the utilization of nitrogen and promote plant growth.

Experiment Study on the Effect of Aluminum Sulfate-Based Alkali-Free Accelerator and the w/c on Cement Hydration and Leaching.

The alkali-free accelerator based on aluminum sulfate is widely used in shotcrete in tunnels. Long-term Ca-leaching of shotcrete may adversely affect the tunnels in a water-rich mountain. It is necessary to examine further the impact of the AS accelerator and w/c on cement hydration and leaching. In this study, all the cement pastes were cured in the environment with R.H. > 95% and 20 ± 1 °C for 60 days and leached in a running water test with 6 M NH4Cl at 1 cm/s. The hydration kinetics was characterized by isothermal calorimetry. Additionally, the microstructural and mineralogical alterations were characterized by XRD, SEM, MIP, and N2 absorption. The results show that (1) the AS accelerator affected the hydration kinetics of cement by stimulating early hydration and delaying the late silicate hydration, resulting in AS-accelerated cement pastes with rougher pore structure. As a result, the higher the dose of AS accelerator, the faster the cement pastes will leach. (2) Hydration kinetics of the accelerated cement are not affected by the w/c. The AS-accelerated cement pastes with lower w/c have a denser pore structure. So, the reduction in the w/c contributes to leaching resistance.

Quantum Simulation of the Radical Pair Dynamics of the Avian Compass.

The simulation of open quantum dynamics on quantum circuits has attracted wide interests recently with a variety of quantum algorithms developed and demonstrated. Among these, one particular design of a unitary-dilation-based quantum algorithm is capable of simulating general and complex physical systems. In this paper, we apply this quantum algorithm to simulating the dynamics of the radical pair mechanism in the avian compass. This application is demonstrated on the IBM QASM quantum simulator. This work is the first application of any quantum algorithm to simulating the radical pair mechanism in the avian compass, which not only demonstrates the generality of the quantum algorithm but also opens new opportunities for studying the avian compass with quantum computing devices.

Pyrolysis characteristics, kinetics, and biochar of fermented pine sawdust-based waste.

The objective of current study is to explore the energy recovery potential of fermentation residues. In this perspective, pyrolysis characteristics, kinetics, and modified biochar derived from pine sawdust after fermentation (FPD) were determined, and comparison was established with pine sawdust (PD). The variation range of comprehensive pyrolysis index (CPI) values of FPD was found 6.51 × 10-7-16.38 × 10-7%2·min-2·°C-3, significantly higher than that of untreated samples determined under the same experimental conditions. The average activation energy of FPD was 367.95 kJ/mol, 389.45 kJ/mol, and 346.55 kJ/mol calculated by Flynn-Wall-Ozawa (FWO) method, Kissinger-Akahira-Sonuse (KAS), and Starink method respectively, and importantly, these values are much higher than those of PD. Additionally, fermentation could enhance the adsorption capacity for methylene blue of biochar from 0.76 mg/g to 1.6 mg/g due to the abundant surface functional groups and three-dimensional internal pore structure. The adsorption pattern of fermented pine wood shifted from chemisorption dominated to the synergetic adsorption of surface functional groups adsorption and intragranular filling. These results show that FPD has favorable pyrolytic properties, and the derived biochar has adsorption properties, which is the basis for designing pyrolysis process and reusing fermentation residues. HIGHLIGHTS: The FPD has higher values of CPI and activation energy than the PD. FPD-derived biochar has higher adsorption capacity than PD-derived biochar. The fermentation improves the pyrolysis performance. The fermentation enhances adsorption capacity due to unique structure of biochar.

Enhanced Strength-Ductility Synergy Properties in Selective Laser Melted 316L Stainless Steel by Strengthening Grinding Process.

Selective laser melted (SLM) 316L stainless steel (SS) has been widely employed in the fields of designing and manufacturing components with complex shapes and sizes. However, the low yield strength, low ultimate tensile stress, and low hardness of SLM 316L SS components hinder its further application. In this work, the strengthening grinding process (SGP) was used to enhance the mechanical properties of SLM 316L SS. The microhardness, residual stress, microstructure, and tensile properties of all the samples were analyzed. The results demonstrate that the SGP induced higher compressive residual stress and microhardness, as well as higher tensile properties. The maximum hardness and residual stress reached 354.5 HV and -446 MPa, respectively, indicating that the SGP resulted in a plastic deformation layer over 150 µm. The possible mechanisms have been discussed in further detail. Compared to the untreated sample, the SGP sample shows a significant improvement in yield strength (YS), ultimate tensile stress (UTS), and elongation (EL), increasing 30%, 25.5%, and 99.1%, respectively. This work demonstrates that SGP treatment could be an efficient approach to simultaneously improving the strength and ductility of the SLM 316L SS, which makes it more suitable for engineering applications.

In Situ Constructing a Stable Solid Electrolyte Interface by Multifunctional Electrolyte Additive to Stabilize Lithium Metal Anodes for Li-S Batteries.

Lithium (Li) metal is considered to be the most promising anode due to the ultrahigh capacity and extremely low electrochemical potential. The tricky thing is that the growth of dendritic Li brings huge safety hazards to Li metal batteries. Herein, we demonstrate cerium nitrate as a multifunctional electrolyte additive to form a stable solid electrolyte interface on the metallic Li anode surface for durable Li-S batteries. The presence of Ce3+ helps to modulate the electroplating/stripping of Li and inhibits the growth of dendritic Li. An excellent cycle life exceeding 1400 h at the current density of 1 mA cm-2 can be realized in symmetric Li||Li cells. In addition, the in situ formed robust solid-electrolyte interface (SEI) layer containing cerium sulfide on the Li anode surface conduces to weaken the reducibility of Li and regulate the electrochemical dissolution/deposition reaction on the Li anode. Surprisingly, by virtue of cerium nitrate additive with a low concentration of 0.03 M, the Li-S batteries can afford a capacity of 553 mA h g-1 at 5 C and a long cycle life at 1 C with a high capacity retention of 70.4%. Therefore, this study provides a novel idea to realize a uniform and dendrite-free Li anode for practical Li-S batteries.

Full recycling of high-value resources from cabbage waste by multi-stage utilization.

Cabbage waste (CW) was recycled for generating some potential high-value products by a multi-stage treatment technology. A novel multi-stage utilization process was successfully proposed which consisted of low-temperature extraction, medium-temperature thermolysis, and high-temperature activation. Plant extracts that contain fatty acids, alcohol, furan, and esters were first extracted from raw cabbage waste by ethanol at 70 °C. Pyrolytic oil was obtained by cabbage waste pyrolysis at different medium temperature conditions. The produced carbon residue was further activated at high temperature for environmental purification such as VOCs removal. The performance of this process was characterized by N2 isothermal adsorption, Fourier transform infrared spectrometer (FTIR), thermogravimetric analysis (TG) and gas chromatography-mass spectrometry (GC-MS). Experimental results showed that the optimum temperatures for extraction, pyrolysis, and activation were 70 °C, 520 °C and 700 °C, respectively. Phenolic-rich pyrolysis solution with 50% phenolic contents could be obtained with the potential application of botanical pesticide. The produced biochar had a BET surface area of as high as 891.12 m2/g. The yields of biochar, pyrolytic liquid, and pyrolytic gas were 43.86%, 17.47%, 38.67%, respectively, and the process energy efficiency was over 42.7%. Applicability and feasibility of this process were also discussed in the aspects of energy quality balance, economy, and environment. The proposed multi-stage thermal-chemical process could be used as a full recycling method for biomass waste.

Tribological Properties of Ti6Al4V Alloy Composite Texture Fabricated by Ultrasonic Strengthening Grinding and Laser Processing.

The Ti6Al4V alloy has been widely used in aerospace equipment and medical devices. However, the poor wear resistance of the Ti6Al4V alloy hinders its further engineering application. In this study, the ultrasonic strengthening grinding process (USGP) and laser texturing process were employed to enhance the wear resistance of Ti6Al4V alloy. The frictional behavior of all samples was determined via a ball-on-disc friction and wear tester under dry conditions. The worn surface morphology, cross-sectional hardness, surface roughness, and microstructure were analyzed. The results demonstrated that the USGP induced high hardness, high dislocation density, and grain refinement, as well as improvements in the wear resistance of Ti6Al4V. Moreover, laser texture could enhance the capacity to capture wear debris and reduce wear probability. When combining the USGP and laser texturing process for the surface treatment of Ti6Al4V alloy, the lowest and most stable friction coefficients were obtained, as well as the best wear resistance. Compared to the polished sample, the steady stage friction coefficient of the sample treated by USGP and laser texturing process was remarkably decreased by 58%. This work demonstrates that combining the USGP and laser texturing process could be a promising solution for improving the wear resistance properties of Ti6Al4V alloy, which makes it more suitable for various engineering applications.

Mid-Infrared Scattering in γ-Al2O3 Catalytic Powders.

The energy efficiency of heterogeneous catalytic processes may be improved by using mid-infrared light to excite gas-phase reactants during the reaction, since vibrational excitation of molecules has been shown to increase their reactivity at the gas-catalyst interface. A primary challenge for such light-enabled catalysis is the need to ensure close coupling between light-excited molecules and the catalyst throughout the reactor. Thus, it is imperative to understand how to couple infrared light efficiently to molecules near and inside catalytic material. Heterogenous catalysts are often nanoscale metal particles supported on high surface area, porous oxide materials and exhibit feature sizes across multiple scattering regimes with respect to the mid-infrared wavelength. These complex powders make a direct measurement of the scattering properties challenging. Here, we demonstrate that a combination of directional hemispherical measurements along with the in-line transmission measurement allow for a direct measurement of the scattered light signal. We implement this technique to study the scattering behavior of the catalytic support material γ-Al2O3 (with and without metal loading) between 1040 and 1220 cm-1. We first study how both the mean grain size affects the scattering behavior by comparing three different mean grain sizes spanning three orders of magnitude (2, 40, and 900 µm). Furthermore, we study how the addition of metal catalyst nanoparticles, Ru, or Cu, to the support material impacts the light scattering behavior of the powder. We find that the 40 µm grain size scatters the most (up to 97% at 1220 cm-1) and that the addition of metal nanoparticles narrows the scattering angle but does not decrease the scattering efficiency. The strong scattering of the 40 µm grains makes them the most ideal support material of those studied for the given spectrum because of their ability to distribute light within the reactor. Finally, we estimate that less than 100 mW of laser power is needed to cause significant excitation for testing mid-infrared catalysis in a Harrick Praying Mantis diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) reactor, a magnitude easily available using commercial mid-infrared lasers. Our work also provides a mid-infrared foundation for a wide range of studies of light-enabled catalysis and can be extended to other wavelengths of light or to study the scattering behavior of other complex powders in other fields, including ceramics, biomaterials, and geology.

Laplacian Pyramid Neural Network for Dense Continuous-Value Regression for Complex Scenes.

Many computer vision tasks, such as monocular depth estimation and height estimation from a satellite orthophoto, have a common underlying goal, which is regression of dense continuous values for the pixels given a single image. We define them as dense continuous-value regression (DCR) tasks. Recent approaches based on deep convolutional neural networks significantly improve the performance of DCR tasks, particularly on pixelwise regression accuracy. However, it still remains challenging to simultaneously preserve the global structure and fine object details in complex scenes. In this article, we take advantage of the efficiency of Laplacian pyramid on representing multiscale contents to reconstruct high-quality signals for complex scenes. We design a Laplacian pyramid neural network (LAPNet), which consists of a Laplacian pyramid decoder (LPD) for signal reconstruction and an adaptive dense feature fusion (ADFF) module to fuse features from the input image. More specifically, we build an LPD to effectively express both global and local scene structures. In our LPD, the upper and lower levels, respectively, represent scene layouts and shape details. We introduce a residual refinement module to progressively complement high-frequency details for signal prediction at each level. To recover the signals at each individual level in the pyramid, an ADFF module is proposed to adaptively fuse multiscale image features for accurate prediction. We conduct comprehensive experiments to evaluate a number of variants of our model on three important DCR tasks, i.e., monocular depth estimation, single-image height estimation, and density map estimation for crowd counting. Experiments demonstrate that our method achieves new state-of-the-art performance in both qualitative and quantitative evaluation on the NYU-D V2 and KITTI for monocular depth estimation, the challenging Urban Semantic 3D (US3D) for satellite height estimation, and four challenging benchmarks for crowd counting. These results demonstrate that the proposed LAPNet is a universal and effective architecture for DCR problems.