Background-free dual-mode optical and 13C magnetic resonance imaging in diamond particles.

Multimodal imaging-the ability to acquire images of an object through more than one imaging mode simultaneously-has opened additional perspectives in areas ranging from astronomy to medicine. In this paper, we report progress toward combining optical and magnetic resonance (MR) imaging in such a "dual" imaging mode. They are attractive in combination because they offer complementary advantages of resolution and speed, especially in the context of imaging in scattering environments. Our approach relies on a specific material platform, microdiamond particles hosting nitrogen vacancy (NV) defect centers that fluoresce brightly under optical excitation and simultaneously "hyperpolarize" lattice [Formula: see text] nuclei, making them bright under MR imaging. We highlight advantages of dual-mode optical and MR imaging in allowing background-free particle imaging and describe regimes in which either mode can enhance the other. Leveraging the fact that the two imaging modes proceed in Fourier-reciprocal domains (real and k-space), we propose a sampling protocol that accelerates image reconstruction in sparse-imaging scenarios. Our work suggests interesting possibilities for the simultaneous optical and low-field MR imaging of targeted diamond nanoparticles.

Premonitory symptoms in migraine from China: A multi-clinic study of 4821 patients.

OBJECTIVE: To observe the prevalence and characteristics of premonitory symptoms in Chinese migraineurs and explore their associations with migraine-related factors. METHOD: Migraineurs who visited a tertiary headache clinic and one of nine neurology clinics between May 2014 and November 2019 were studied. RESULT: Among the 4821 patients meeting the migraine criteria (International Classification of Headache Disorders, 3rd edition), 1038 (21.5%) patients experienced at least one premonitory symptom. The most common premonitory symptoms were neck stiffness, dizziness, yawning and drowsiness. The logistic regression analysis demonstrated that aura, photophobia, aggravation by routine physical activity, triggers, family history, depression, coffee consumption and physical exercise were associated with an increased probability of experiencing premonitory symptoms (p ≤ 0.001). The premonitory symptoms of migraine with and without aura differ in prevalence and most common symptoms. The cluster analysis revealed pairwise clustering of the following premonitory symptoms: Photophobia/phonophobia, concentration change/dysesthesia, loquacity/overactivity, yawning/drowsiness, fatigue/dizziness, and mood change/irritability. The correlation analysis of triggers and premonitory symptoms revealed that temperature change, environment change, sleep disorder, activity and stress were related to multiple premonitory symptoms, and that food, light, menstruation, alcohol and odor were related to special premonitory symptoms (p ≤ 0.001). CONCLUSION: The prevalence of premonitory symptoms among migraineurs in China is 21.5%. Some factors influence the probability of experiencing premonitory symptoms. Paired premonitory symptoms in the clustering analysis may share similar origins. Certain triggers associated with multiple premonitory symptoms may induce brain dysfunction; however, other triggers that overlap with corresponding special premonitory symptoms may be premonitory symptoms or a form of premonitory symptom.

CFNet: LiDAR-Camera Registration Using Calibration Flow Network.

As an essential procedure of data fusion, LiDAR-camera calibration is critical for autonomous vehicles and robot navigation. Most calibration methods require laborious manual work, complicated environmental settings, and specific calibration targets. The targetless methods are based on some complex optimization workflow, which is time-consuming and requires prior information. Convolutional neural networks (CNNs) can regress the six degrees of freedom (6-DOF) extrinsic parameters from raw LiDAR and image data. However, these CNN-based methods just learn the representations of the projected LiDAR and image and ignore the correspondences at different locations. The performances of these CNN-based methods are unsatisfactory and worse than those of non-CNN methods. In this paper, we propose a novel CNN-based LiDAR-camera extrinsic calibration algorithm named CFNet. We first decided that a correlation layer should be used to provide matching capabilities explicitly. Then, we innovatively defined calibration flow to illustrate the deviation of the initial projection from the ground truth. Instead of directly predicting the extrinsic parameters, we utilize CFNet to predict the calibration flow. The efficient Perspective-n-Point (EPnP) algorithm within the RANdom SAmple Consensus (RANSAC) scheme is applied to estimate the extrinsic parameters with 2D-3D correspondences constructed by the calibration flow. Due to its consideration of the geometric information, our proposed method performed better than the state-of-the-art CNN-based methods on the KITTI datasets. Furthermore, we also tested the flexibility of our approach on the KITTI360 datasets.

Imaging Sequences for Hyperpolarized Solids.

Hyperpolarization is one of the approaches to enhance Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI) signal by increasing the population difference between the nuclear spin states. Imaging hyperpolarized solids opens up extensive possibilities, yet is challenging to perform. The highly populated state is normally not replenishable to the initial polarization level by spin-lattice relaxation, which regular MRI sequences rely on. This makes it necessary to carefully "budget" the polarization to optimize the image quality. In this paper, we present a theoretical framework to address such challenge under the assumption of either variable flip angles or a constant flip angle. In addition, we analyze the gradient arrangement to perform fast imaging to overcome intrinsic short decoherence in solids. Hyperpolarized diamonds imaging is demonstrated as a prototypical platform to test the theory.

Monoammonium Porphyrin for Blade-Coating Stable Large-Area Perovskite Solar Cells with >18% Efficiency.

Efficient control of crystallization and defects of perovskite films are the key factors toward the performance and stability of perovskite solar cells (PSCs), especially for the preparation of large-area PSCs devices. Herein, we directly embedded surfactant-like monoammonium zinc porphyrin (ZnP) compound into the methylammonium (MA+) lead iodide perovskite film to blade-coat large-area uniform perovskite films as large as 16 cm2. Efficiency as high as 18.3% for blade-coating large-area (1.96 cm2) PSCs with ZnP was unprecedentedly achieved, while the best efficiency of fabricated small-area (0.1 cm2) device was up to 20.5%. The detailed analyses demonstrated the functions of ZnP in crystallization control and defects passivation of perovskite surfaces and grain boundaries. As a consequence, the ZnP-encapsulated devices retained over 90% of its initial efficiency after 1000 h with a humidity of about 45% at 85 °C. This research presents a facile way to achieve the synergistic effect of large-area coating, morphology tailoring, and defect suppression based on the molecular encapsulation strategy for perovskite films, further improving the photovoltaic performance and stability of PSCs.

Efficient Grain Boundary Suture by Low-Cost Tetra-ammonium Zinc Phthalocyanine for Stable Perovskite Solar Cells with Expanded Photoresponse.

Defects within the grain boundaries (GBs) of halide perovskite films make fabrication of efficient and stable perovskite solar cells (PSCs) highly challenging. Here, a low-cost tetra-ammonium zinc phthalocyanine (ZnPc) was used to post-treat the MAPbI3 (MA = CH3NH3) film. Two-dimensional (ZnPc)0.5MA n-1Pb nI3 n+1 was successfully constructed within the GBs of MAPbI3 film achieving a GBs suture for passivating the defects in GBs. Time-resolved photoluminescence showed that the modification increased the decay time from 44 to 57 ns indicating the passivation of GBs reduces trap-assisted recombination. The PSCs with modified perovskite exhibited increased photovoltage, and the best efficiency was improved up to 20.3%. More importantly, the long-term stability of the responding PSCs against humidity and heating was further improved unprecedentedly. Moreover, the modified MAPbI3 films revealed a self-repairing capability under mild heating. This work provided a novel insight into ongoing fabrication of efficient and stable PSCs by the efficient GBs suture with low-cost phthalocyanine.

Validation of a guideline-based decision support system for the diagnosis of primary headache disorders based on ICHD-3 beta.

BACKGROUND: China may have the largest population of headache sufferers and therefore the most serious burden of disease worldwide. However, the rate of diagnosis for headache disorders is extremely low, possibly due to the relative complexity of headache subtypes and diagnostic criteria. The use of computerized clinical decision support systems (CDSS) seems to be a better choice to solve this problem. METHODS: We developed a headache CDSS based on ICHD-3 beta and validated it in a prospective study that included 543 headache patients from the International Headache Center at the Chinese PLA General hospital, Beijing, China. RESULTS: We found that the CDSS correctly recognized 159/160 (99.4%) of migraine without aura, 36/36 (100%) of migraine with aura, 20/21 (95.2%) of chronic migraine, and 37/59 (62.7%) of probable migraine. This system also correctly identified 157/180 (87.2%) of patients with tension-type headache (TTH), of which infrequent episodic TTH was diagnosed in 12/13 (92.3%), frequent episodic TTH was diagnosed in 99/101 (98.0%), chronic TTH in 18/20 (90.0%), and probable TTH in 28/46 (60.9%). The correct diagnostic rates of cluster headache and new daily persistent headache (NDPH) were 90.0% and 100%, respectively. In addition, the system recognized 32/32 (100%) of patients with medication overuse headache. CONCLUSIONS: With high diagnostic accuracy for most of the primary and some types of secondary headaches, this system can be expected to help general practitioners at primary hospitals improve diagnostic accuracy and thereby reduce the burden of headache in China.

Reactive high-spin iron(IV)-oxo sites through dioxygen activation in a metal-organic framework.

In nature, nonheme iron enzymes use dioxygen to generate high-spin iron(IV)=O species for a variety of oxygenation reactions. Although synthetic chemists have long sought to mimic this reactivity, the enzyme-like activation of O2 to form high-spin iron(IV) = O species remains an unrealized goal. Here, we report a metal-organic framework featuring iron(II) sites with a local structure similar to that in α-ketoglutarate-dependent dioxygenases. The framework reacts with O2 at low temperatures to form high-spin iron(IV) = O species that are characterized using in situ diffuse reflectance infrared Fourier transform, in situ and variable-field Mössbauer, Fe Kß x-ray emission, and nuclear resonance vibrational spectroscopies. In the presence of O2, the framework is competent for catalytic oxygenation of cyclohexane and the stoichiometric conversion of ethane to ethanol.

Continuous Modification of Perovskite Film by a Eu Complex to Fabricate the Thermal and UV-Light-Stable Solar Cells.

Perovskite solar cells (PSCs) with simple and low-cost processability have shown promising photovoltaic performances. However, internal defects, external UV light, and heat sensitivity are principal obstacles on their way toward commercialization. Herein, we prepare an Eu complex and directly dope it into the perovskite precursor as a UV filter to decrease the photodegradation of PSCs. The formation of hydrogen bonds between the organic cation of perovskite and the -CF3 in the Eu complex could restrain the escape of organic cations under heating. The Eu complex acts as a redox shuttle to reduce metallic lead (Pb0) and iodine (I0) defects when the PSCs have a long-time operation. Additionally, the ligand-containing aromatic rings could reduce the trace amount of I0 existing as electronic defects in perovskites and together with the long alkyl chain retard the moisture immersion into the PSCs. The best efficiency of PSCs modified by the Eu complex improves up to 20.9%. The excellent thermal stability and UV-light resistance are also realized. This strategy provides a method to design a passivator which continuously modifies the imperfections and inhibits the chemical chain reactions in perovskite film, thereby enhancing the performance and stability of PSCs.

MiR-181 Enhances Proliferative and Migratory Potentials of Retinal Endothelial Cells in Diabetic Retinopathy by Targeting KLF6.

PURPOSE: We aimed to uncover the role of microRNA-181 (miR-181) in the disease onset of diabetic retinopathy (DR) and its underlying mechanism. METHODS: MiR-181 levels in plasma and aqueous humor samples of non-proliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR) and healthy subjects were analyzed by microarray and quantitative real-time polymerase chain reaction (qRT-PCR). Proliferative and migrative capacities of human retinal endothelial cells (hRECs) regulated by miR-181 were assessed. The binding between miR-181 and Kruppel-like factor 6 (KLF6) was verified by dual-luciferase reporter assay. RESULTS: MiR-181 was upregulated in plasma and aqueous humor samples of NPDR and PDR patients. Overexpression of miR-181 stimulated hRECs to proliferate and migrate. KLF6 was the downstream gene binding miR-181, which was involved in the regulation of hRECs by miR-181. CONCLUSIONS: MiR-181 is upregulated in plasma and aqueous humor of DR patients. It enhances proliferative and migratory potentials of retinal endothelial cells by targeting KLF6.

A scalable solid-state nanoporous network with atomic-level interaction design for carbon dioxide capture.

Carbon capture and sequestration reduces carbon dioxide emissions and is critical in accomplishing carbon neutrality targets. Here, we demonstrate new sustainable, solid-state, polyamine-appended, cyanuric acid-stabilized melamine nanoporous networks (MNNs) via dynamic combinatorial chemistry (DCC) at the kilogram scale toward effective and high-capacity carbon dioxide capture. Polyamine-appended MNNs reaction mechanisms with carbon dioxide were elucidated with double-level DCC where two-dimensional heteronuclear chemical shift correlation nuclear magnetic resonance spectroscopy was performed to demonstrate the interatomic interactions. We distinguished ammonium carbamate pairs and a mix of ammonium carbamate and carbamic acid during carbon dioxide chemisorption. The coordination of polyamine and cyanuric acid modification endows MNNs with high adsorption capacity (1.82 millimoles per gram at 1 bar), fast adsorption time (less than 1 minute), low price, and extraordinary stability to cycling by flue gas. This work creates a general industrialization method toward carbon dioxide capture via DCC atomic-level design strategies.

Diammonium Porphyrin-Induced CsPbBr3 Nanocrystals to Stabilize Perovskite Films for Efficient and Stable Solar Cells.

Employing all-inorganic perovskite quantum dots (QDs) to treat organic-inorganic perovskite films has been well documented as a serviceable tactic to improve the performance of perovskite solar cells (PSCs). However, the inert molecule-coated QDs with zero-dimensional (0D) structure would limit further enhancement of the efficiency and stability of PSCs. Here, we employ a conductive diammonium porphyrin (ZnPy-NH3Br) to treat CsPbBr3 QDs coated on a three-dimensional perovskite film, thus constructing a stable 0D-two-dimensional perovskite capping layer. The generation of large-scale nanocube crystals by treating CsPbBr3 nanocrystallites with ZnPy-NH3Br in solution demonstrates such an assembly strategy. The formed capping layer can achieve efficient charge transport and separation. As a consequence, the best efficiency of an optimized device is up to 20.0%, which is superior to the control PSCs fabricated without modification (19.1%) and with pure CsPbBr3 QD modification (19.5%). More importantly, the porphyrin-treated CsPbBr3 QD-based devices retain over 65 or 85% of their initial efficiency when placed at 85 °C or 45% humidity tracking for 1000 h, respectively. Also, with the incorporation of QD-Por, the device retained 85% of the original efficiency when illuminated at AM 1.5 G for 450 h. Therefore, this work offered a facile avenue to modify perovskite films for fabricating highly efficient and stable PSCs.

Determination methods for steady-state concentrations of HO• and SO4•- in electrochemical advanced oxidation processes.

Competitive kinetics and scavenging assay are commonly used for radical quantification. However, the accuracy of the two methods has been challenged in electrochemical advanced oxidation processes (EAOPs) since the strong reactivity of electrode against organic indicators may disrupt the quantitative relationship between indicator consumption and radical concentration. The present study focused on screening suitable indicators and developing suitable methods for determining the steady-state concentrations of SO4•- and HO• ([SO4•-]ss and [HO•]ss) in several EAOPs for water treatment based on competitive kinetics and scavenging assay. The applicability of the modified methods and available indicators were investigated through experimental and kinetic analysis. In anode alone process, the competitive kinetics was more appropriate than scavenging assay and benzoic acid (BA) met the basic requirement of being a competitor to determine the [HO•]ss. In cathode alone process, BA was more resistant to interfering factors than other competitors (ibuprofen, atrazine and nitrobenzene) and its reaction rate involved only the radical oxidation even when the reaction conditions varied over a wide range. Therefore, the [HO•]ss could be obtained by the competitive kinetic equation of BA when HO• existed alone. When HO• coexisted with SO4•-, a two-step method combining scavenging assay and competitive kinetics was proposed to measure [SO4•-]ss and [HO•]ss, in which tert-butyl alcohol and BA were added as scavenger and competitor, respectively. Furthermore, the reliability of each approach was verified by the experimental results and kinetic analysis.

Designing hierarchical nanoporous membranes for highly efficient gas adsorption and storage.

Nanoporous membranes with two-dimensional materials such as graphene oxide have attracted attention in volatile organic compounds (VOCs) and H2 adsorption because of their unique molecular sieving properties and operational simplicity. However, agglomeration of graphene sheets and low efficiency remain challenging. Therefore, we designed hierarchical nanoporous membranes (HNMs), a class of nanocomposites combined with a carbon sphere and graphene oxide. Hierarchical carbon spheres, prepared following Murray's law using chemical activation incorporating microwave heating, act as spacers and adsorbents. Hierarchical carbon spheres preclude the agglomeration of graphene oxide, while graphene oxide sheets physically disperse, ensuring structural stability. The obtained HNMs contain micropores that are dominated by a combination of ultramicropores and mesopores, resulting in high VOCs/H2 adsorption capacity, up to 235 and 352 mg/g at 200 ppmv and 3.3 weight % (77 K and 1.2 bar), respectively. Our work substantially expands the potential for HNMs applications in the environmental and energy fields.

[Design and application of medical knowledge model on SAGE].

As an methodology for promoting the quality and efficiency of health care, clinical decision support systems (CDSSs) have gained much improvement. The knowledge base (KB) plays an important role in DSS. For CDSSs, the construction of KB means modeling the medical knowledge based on a suitable model. This study analyzes the SAGE model, then implements it on knowledge of diagnosis and treatment of Metabolic Syndrome (MS), and improves the SAGE to enhance its expression ability. The model is constructed as the KB in CDSS, and be applied in hospital. The evaluation result of CDSS reveals that the SAGE model should be useful in clinical application. Finally, this study propounds some points yet to be improved in the SAGE.

Cerium-Oxide-Modified Anodes for Efficient and UV-Stable ZnO-Based Perovskite Solar Cells.

CeO x has been widely used in optoelectronic devices due to its special electronic and optical structure. Herein, CeO x was directly doped into ZnO to successfully construct a ZnO/CeO x electron transport material (ETM) used in perovskite solar cells (PSCs). The incorporation of CeO x can regulate the chemical compatibility between ZnO and perovskite, unmatched energy levels, and poor UV stability, further enhancing the cell performance and stability of PSCs. As expected, the best efficiency of fabricated CH3NH3PbI3-PSCs based on ZnO/CeO x as the ETM was up to 19.5%. In contrast, the efficiency of PSCs with pure ZnO was 16.0%. Moreover, compared with PSCs based on ZnO, ZnO/CeO x-based PSCs exhibited significantly enhanced moisture, and thermal and UV stability. These results point to the introduction of rare-earth oxides, which could accelerate the industrialization of PSCs.

Perfection of Perovskite Grain Boundary Passivation by Eu-Porphyrin Complex for Overall-Stable Perovskite Solar Cells.

The formation of defects at surfaces and grain boundaries (GBs) during the fabrication of solution-processed perovskite film are thought to be responsible for its instability. Herein, Eu-porphyrin complex (Eu-pyP) is directly doped into methylammonium lead triiodide (MAPbI3) precursor, perfectly fabricating 2D (Eu-pyP)0.5MA n -1Pb n I3 n +1 platelets inlaying the GBs of 3D polycrystalline interstices in this protocol. The device based on Eu-pyP doped perovskite film possesses a champion efficiency of 18.2%. More importantly, the doped perovskite solar cells device shows beyond 85% retention of its pristine efficiency value, whereas the pure MAPbI3 device has a rapid drop in efficiency down to 10% within 100 h under 45% humidity at 85 °C in AM 1.5 G. The above acquired perovskite films reveal an unpredictable thermodynamic self-healing ability. Consequently, the findings provide an avenue for defect passivation to synchronously improve resistibility to moisture, heat, and solar light including UV.

Comparison of inert and non-inert cathode in cathode/Fe3+/Peroxymonosulfate processes on iohexol degradation.

To investigate the effect of cathode materials on organics degradation in a cathode/Fe3+/PMS process, different cathode materials (platinum, copper and iron) were selected and their performances were compared with iohexol as target organics. The optimal conditions were found to be different for different cathode/Fe3+/PMS processes. With a relatively high cathodic current input (2.0 mA/cm2), similar results were found for all the three cathode/Fe3+/PMS processes. With a small cathodic current input (not higher than 1.0 mA/cm2), the iohexol removal followed the order of Fe-cathode/Fe3+/PMS > Cu-cathode/Fe3+/PMS > Pt-cathode/Fe3+/PMS, due to the corrosion of Cu-cathode and Fe-cathode and the more serious corrosion of Fe-cathode than Cu-cathode. The corrosion of non-inert cathode materials (Cu-cathode and Fe-cathode) meant that these cathodes not only transmitted electrons but also participated in aqueous reactions, which complicated the mechanisms of cathode/Fe3+/PMS processes. The radical identification experiments indicated that SO4- was more important than OH for iohexol degradation in Cu-cathode/Fe3+/PMS process, while OH played a major role in Pt-cathode/Fe3+/PMS and Fe-cathode/Fe3+/PMS processes. The different reaction mechanisms resulted in different iohexol transformation pathways in cathode/Fe3+/PMS processes with different cathode materials.

Performance of Cu-cathode/Fe3+/peroxymonosulfate process on iohexol degradation.

Copper was used as a non-inert cathode material in a Cathode/Fe3+/peroxymonosulfate(PMS) system, and the performance of this novel Cu-cathode/Fe3+/PMS system was tested with a typical iodinated X-ray contrast media (iohexol) as target organics. The reaction mechanisms and the iohexol degradation pathways were investigated. The operational conditions of Cu-cathode/Fe3+/PMS process on iohexol degradation were optimized to be 1.0 mM Fe3+ dosage, 3.0 mM PMS dosage and 0.50 mA/cm2 of current input. The much lower current applied in the present study than previous reports would help to save energy and be more economical. Compared with typical inert cathode (Pt-cathode), the Cu-cathode/Fe3+/PMS process has better performance on both iohexol removal and deiodination, due to that Cu-cathode participated in Fe2+ regeneration and PMS activation via surface Cu°-Cu+(s)-Cu2+-Cu° redox cycle. Fe2+ could be produced via reactions between Fe3+ and Cu/Cu+(s) as well as cathodic reduction of Fe3+. SO4- was generated from PMS activation by Fe2+, Cu/Cu+(s) and cathodic reduction. OH was also generated in this process but SO4- played a dominant role in iohexol degradation. The intermediate products of iohexol and its transformation pathways were complex due to the varied reaction mechanisms involving both oxidation and reduction in Cu-cathode/Fe3+/PMS process.

Solvent-based separation and recycling of waste plastics: A review.

Since the creation of first man-made plastic, the global production and consumption of plastics have been continuously increasing. However, because plastic materials are durable and very slow to degrade, they become waste with high staying power. The over-consumption, disposal, and littering of plastics result in pollution, thus causing serious environmental consequences. To date, only a fraction of waste plastics is reused and recycled. In fact, recycling plastics remains a great challenge because of technical challenges and relatively insufficient profits, especially in mixed plastics. This review focuses on an environmentally friendly and potentially profitable method for plastics separation and recovery and solvents extraction. It includes the dissolution/reprecipitation method and supercritical fluid extraction, which produce high-quality recovered plastics comparable to virgin materials. These methods are summarized and discussed taking mass-produced plastics (PS, PC, Polyolefins, PET, ABS, and PVC) as examples. To exploit the method, the quality and efficiency of solvent extraction are elaborated. By eliminating these technical challenges, the solvent extraction method is becoming more promising and sustainable for plastic issues and polymer markets.