Radical and ionic meta -C–H functionalization of pyridines, quinolines, and isoquinolines

Carbon-hydrogen (C−H) functionalization of pyridines is a powerful tool for the rapid construction and derivatization of many agrochemicals, pharmaceuticals, and materials. Because of the inherent electronic properties of pyridines, selective meta -C−H functionalization is challenging. Here, we present a protocol for highly regioselective meta -C−H trifluoromethylation, perfluoroalkylation, chlorination, bromination, iodination, nitration, sulfanylation, and selenylation of pyridines through a redox-neutral dearomatization-rearomatization process. The introduced dearomative activation mode provides a diversification platform for meta-selective reactions on pyridines and other azaarenes through radical as well as ionic pathways. The broad scope and high selectivity of these catalyst-free reactions render these processes applicable for late-stage functionalization of drugs.

Nerve-spring technique could achieve a functional trifecta outcome of robotic intracorporeal studer’s orthotopic neobladder in the male

Objectives: To summarize some key steps of functional improvement in robotic intracorporeal studer’s orthotopic neobladder (RISON) of males, especially for nerve-spring technique. We also presented the result of 1-year follow-up aimed to illustrate its functional trifecta outcomes.Methods: Robotic radical cystectomy with intracorporeal studer’s orthotopic neobladder was performed on 33 male patients by the same surgeon from April 2018 to March 2019. Nerve-sparing technique had been used in 11 of the 33 patients. A prospectively maintained dataset was retrospectively searched and the related perioperative and follow-up data were analyzed. The functional trifecta outcomes referred to the freedom from recurrence, urinary continence and sexual function recovery after one year.Results: A total of 33 males were included in our study. All perioperative information was recorded in detail. Thirty-two cases were confirmed to have negative surgical margin, except one pT3a case. And another case of incidental prostate cancer was diagnosed pathologically. All patients (100%) were recurrence-free one year after the operation. Eleven patients underwent nerve-sparing surgeries, including inter-fascial techniques or intra-fascial techniques. All these patients attained daytime continence (0 pad) at 1 month. With the nighttime continence, nerve-sparing group (2, 2 ,1) used fewer pads than other 22 cases (3, 3 ,2) at 1, 6 or 12 month(s) respectively. We defined urinary continence as 0 pad in daytime and no more than 1 pad in nighttime. The median preoperative score of International Index of Erectile Function (IIEF-6) in the 11 cases was 24. The sexual function recovery was defined as IIEF-6 > 20. The final trifecta rate was 54.5% and the median follow-up time lasted 17 months (range, 12 to 22 months). Conclusions: RISON could be a safe and feasible choice of urinary diversion. Nerve sparing techniques might help the patients achieve a relatively higher functional trifecta rate.

Deep learning algorithm reveals probabilities of stage-specific time to conversion in individuals with neurodegenerative disease LATE

Introduction

Limbic-predominant age-related TAR DNA-binding protein 43 (TDP-43) encephalopathy (LATE) is a recently defined neurodegenerative disease. Currently, there is no effective way to make a prognosis of time to stage-specific future conversions at an individual level.

Methods

After using the Kaplan-Meier estimation and log-rank test to confirm the heterogeneity of LATE progression, we developed a deep learning-based approach to assess the stage-specific probabilities of time to LATE conversions for different subjects.

Results

Our approach could accurately estimate the disease incidence and transition to next stages: the concordance index was at least 82% and the integrated Brier score was less than 0.14. Moreover, we identified the top 10 important predictors for each disease conversion scenario to help explain the estimation results, which were clinicopathologically meaningful and most were also statistically significant.

Discussion

Our study has the potential to provide individualized assessment for future time courses of LATE conversions years before their actual occurrence.

Space-frequency-polarization-division multiplexed wireless communication system using anisotropic space-time-coding digital metasurface

In the past few years, wireless communications based on digital coding metasurfaces have gained research interest owing to their simplified architectures and low cost. However, in most of the metasurface-based wireless systems, a single-polarization scenario is used, limiting the channel capacities. To solve the problem, multiplexing methods have been adopted, but the system complexity is inevitably increased. Here, a space-frequency-polarization-division multiplexed wireless communication system is proposed using an anisotropic space-time-coding digital metasurface. By separately designing time-varying control voltage sequences for differently oriented varactor diodes integrated on the metasurface, we achieve frequency-polarization-division multiplexed modulations. By further introducing different time-delay gradients to the control voltage sequences in two polarization directions, we successfully obtain space-frequency-polarization-division multiplexed modulations to realize a wireless communication system with a new architecture. The new communication system is designed with compact dual-polarized meta-elements, and can improve channel capacity and space utilization. Experimental results demonstrate the high-performance and real-time transmission capability of the proposed communication system, confirming its potential application in multiple-user collaborative wireless communications.

Challenges and strategies in high-accuracy manufacturing of the world's largest SiC aspheric mirror

In the process of manufacturing the world's largest silicon carbide (SiC) aspheric mirror, the primary difficulties are mirror blank preparation, asphere fabrication, and testing, as well as cladding and coating. Specifically, the challenges include the homogeneity of the complicated structure casting, accuracy and efficiency of the fabrication process, print-through effect, fidelity and precision of test procedure, stress and denseness of cladding process, the dynamic range of interferometric measurement, and air turbulence error due to the long optical path. To break through such a barrier of difficulties, we proposed the water-soluble room temperature vanishing mold and gel casting technology, homogeneous microstructure reaction-formed joint technology, nano-accuracy efficient compound fabrication, gravity unloading technology, high-denseness low-defect physical vapor deposition (PVD) Si-cladding technology, test data fusion method, and time-domain averaging method, etc. Based on the proposed technologies and methods, we have accomplished the world's largest SiC aspheric mirror with a size of ⌀4.03 m. The impressive performance of the SiC aspheric mirror is validated by the characteristics of the fabricated SiC aspheric mirror. The aerial density of the SiC blank is less than 120 kg/m², surface shape test accuracy is better than 6 nm RMS, thickness inhomogeneity of the cladding layer is less than 5%, and the final surface figure error and roughness are 15.2 nm RMS and 0.8 nm RMS, respectively.

[microRNA let-7g-3p regulates proliferation, migration, invasion and apoptosis of bladder cancer cells by targeting HMGB2]

OBJECTIVE

To explore the molecular mechanism by which microRNA let-7g-3p regulates biological behaviors of bladder cancer cells.

METHODS

The expression levels of let-7g-3p in bladder cancer and adjacent tissues, normal bladder epithelial cells (HUC cells) and bladder cancer cells (T24, 5637 and EJ cells) were detected using qRT- PCR. T24 cells were transfected with let-7g-3p mimic or inhibitor, and the changes in cell proliferation, migration, invasion, and apoptosis were examined. Transcriptome sequencing was carried out in cells overexpressing let-7g-3p, and the results of bioinformatics analysis, double luciferase reporter gene assay, qRT-PCR and Western blotting confirmed that HMGB2 gene was the target gene of let-7g-3p. The expression of HMGB2 was examined in HUC, T24, 5637 and EJ cells, and in cells with HMGB2 knockdown, the effect of let-7g-3p knockdown on the biological behaviors were observed.

RESULTS

qRT-qPCR confirmed that let-7g-3p expression was significantly lower in bladder cancer tissues and cells (P < 0.01). Overexpression of let-7g-3p inhibited cell proliferation, migration and invasion, and promoted cell apoptosis, while let-7g-3p knock-down produced the opposite effects. Bioinformatics and transcriptome sequencing results showed that HMGB2 was the key molecule that mediate the effect of let-7g-3p on bladder cancer cells. Luciferase reporter gene assay, qRT-PCR and Western blotting all confirmed that HMGB2 was negatively regulated by let-7g-3p (P < 0.01). Knocking down HMGB2 could partially reverse the effect of let-7g-3p knockdown on the biological behaviors of the bladder cancer cells.

CONCLUSION

The microRNA let-7g-3p can inhibit the biological behavior of bladder cancer cells by negatively regulating HMGB2 gene.

Mutational signature and clonal relatedness of recurrent urothelial carcinomas with aristolochic acid

Urothelial carcinomas (UCs) are malignant tumors that arise from the lower and upper urinary tract and are characterized by multiple recurrences. Aristolochic acid (AA) is a potent nephrotoxin and human carcinogen associated with UC. East Asian populations with a high UC prevalence have an unusual genome-wide AA-induced mutational pattern. To address the genomic differences and clonal relatedness between primary and recurrent tumors in the UCs with AA pattern, we investigated the genomic differences and tumor microenvironment (TME) of AA and non-AA UCs. 17 UC patients were recruited, with nine documented AA exposure. Eleven of them showed recurrence. After-surgery tissues of primary and paired recurrent tumors were collected. Capture-based targeted deep sequencing was performed using a commercial panel consisting of 520 cancer-related genes. Tumor-infiltrating lymphocytes (TILs) were identified with an immunofluorescence-based microenvironment analysis panel (MAP). Hierarchical clustering based on the COSMIC signatures confirmed two significant subtypes: AA Sig and non-AA Sig. AA Sig was associated with AA-containing herbal drug intake, recurrence, and higher tumor mutation burden (TMB). The clonal architecture of UCs revealed three types of clonal evolution patterns. Non-AA Sig cohort showed shared clonal origin of primary and recurrent tumors. AA Sig showed heterogeneity and had multiple independent origins. Recurrent tumors as second primary tumors in AA Sig showed immunoreactive TME, indicating a better response with immune checkpoint inhibitor therapy. The AA mutational signature and unique immune profiles are helpful molecular markers to distinguish AA exposure from other carcinogens. These results also provide new insights into the origin of recurrent UCs that could affect treatment strategies.

Frequency-modulated continuous waves controlled by space-time-coding metasurface with nonlinearly periodic phases

The rapid development of space-time-coding metasurfaces (STCMs) offers a new avenue to manipulate spatial electromagnetic beams, waveforms, and frequency spectra simultaneously with high efficiency. To date, most studies are primarily focused on harmonic generations and independent controls of finite-order harmonics and their spatial waves, but the manipulations of continuously temporal waveforms that include much rich frequency spectral components are still limited in both theory and experiment based on STCM. Here, we propose a theoretical framework and method to generate frequency-modulated continuous waves (FMCWs) and control their spatial propagation behaviors simultaneously via a novel STCM with nonlinearly periodic phases. Since the carrier frequency of FMCW changes with time rapidly, we can produce customized time-varying reflection phases at will by the required FMCW under the illumination of a monochromatic wave. More importantly, the propagation directions of the time-varying beams can be controlled by encoding the metasurface with different initial phase gradients. A programmable STCM prototype with a full-phase range is designed and fabricated to realize reprogrammable FMCW functions, and experimental results show good agreement with the theoretical analyses.

Metasurface-based broadband polarization-insensitive polarization rotator

The polarizations of electromagnetic (EM) waves are very important for transceivers. We propose a broadband polarization-insensitive polarization rotator (PIPR), which can realize 90° polarization rotation for incident waves with an arbitrary azimuth angle. A unit of the PIPR is composed of two types of substrate integrated waveguide (SIW) units in a checkerboard pattern, which provides more than -0.2 dB transmission from 9.5 to 10.9 GHz. The electric field inside the cavity is analyzed to explain the working mechanism of the proposed rotator. A prototype is fabricated and measured to verify the proposed design, and satisfactory agreement between simulated and measured results is achieved, indicating that the converter has potential applications in imaging and communication systems.

Data-driven adaptive integral terminal sliding mode control for uncertain SMA actuators with input saturation and prescribed performance

This paper focuses on the data-driven adaptive control problem of the shape memory alloy (SMA) actuators subject to uncertainties, input saturation and prescribed performance. Firstly, the uncertainties estimation method, anti-windup technology, and prescribed performance function are introduced to deal with uncertain nonlinearity, input constraint, and prespecified performance, respectively. Meanwhile, a general approach about designing asymmetrical convergence bound is presented to increase the flexibility of creating convergence area. Secondly, taking uncertainties, input saturation, and asymmetrical convergence bound into consideration, we design an integral terminal sliding mode controller to guarantee the prescribed tracking accuracy without using the knowledge of the SMA actuators model. Further, the stability of the controller and the boundedness of the convergence error are proved by rigorous theoretical analysis. Finally, the success and superiority of our controller are verified by the SMA actuator experiments.

Asynchronous Space-Time-Coding Digital Metasurface

Recent progress in space-time-coding digital metasurface (STCM) manifests itself a powerful tool to engineer the properties of electromagnetic (EM) waves in both space and time domains, and greatly expands its capabilities from the physical manipulation to information processing. However, the current studies on STCM are focused under the synchrony frame, namely, all meta-atoms follow the same variation frequency. Here, an asynchronous STCM is proposed, where the meta-atoms are modulated by different time-coding periods. In the proposed asynchronous STCM, the phase discontinuities on traditional metasurface are replaced with the frequency discontinuities. It is shown that dynamic wavefronts can be automatically realized for both fundamental and high-order harmonics by elaborately arranging the spatial distribution of meta-atoms with various time-coding periods. The physics insight is due to the accumulated rapidly changing phase difference with time, which offers an additional degree of freedom during the wave-matter interactions. As a proof-of-principle example, an asynchronous STCM for automatic spatial scanning and dynamic scattering control is investigated. From the theory, numerical simulations, and experiments, it can be found that the proposed STCM exhibits significant potentials for applications in radars and wireless communications.

Stabilizing and Enhancing Link Prediction through Deepened Graph Auto-Encoders

Graph neural networks have been widely used for a variety of learning tasks. Link prediction is a relatively under-studied graph learning task, with current state-of-the-art models based on one- or two-layer shallow graph auto-encoder (GAE) architectures. In this paper, we overcome the limitation of current methods for link prediction of non-Euclidean network data, which can only use shallow GAEs and variational GAEs. Our proposed methods innovatively incorporate standard auto-encoders (AEs) into the architectures of GAEs to capitalize on the intimate coupling of node and edge information in complex network data. Empirically, extensive experiments on various datasets demonstrate the competitive performance of our proposed approach. Theoretically, we prove that our deep extensions can inclusively express multiple polynomial filters with different orders. The codes of this paper are available at https://github.com/xinxingwu-uk/DGAE.

A Novel Early Warning Model for Hand, Foot and Mouth Disease Prediction Based on a Graph Convolutional Network

OBJECTIVES

Hand, foot and mouth disease (HFMD) is a widespread infectious disease that causes a significant disease burden on society. To achieve early intervention and to prevent outbreaks of disease, we propose a novel warning model that can accurately predict the incidence of HFMD.

METHODS

We propose a spatial-temporal graph convolutional network (STGCN) that combines spatial factors for surrounding cities with historical incidence over a certain time period to predict the future occurrence of HFMD in Guangdong and Shandong between 2011 and 2019. The 2011-2018 data served as the training and verification set, while data from 2019 served as the prediction set. Six important parameters were selected and verified in this model and the deviation was displayed by the root mean square error and the mean absolute error.

RESULTS

As the first application using a STGCN for disease forecasting, we succeeded in accurately predicting the incidence of HFMD over a 12-week period at the prefecture level, especially for cities of significant concern.

CONCLUSIONS

This model provides a novel approach for infectious disease prediction and may help health administrative departments implement effective control measures up to 3 months in advance, which may significantly reduce the morbidity associated with HFMD in the future.

Population Genomics Reveals Population Structure and Mating-Type Loci in Marssonina brunnea

Marssonina brunnea is an important fungal pathogen of poplar trees. We collected 32 M. brunnea f.sp. multigermtubi (MbMu) and three M. brunnea f.sp. monogermtubi (MbMo) isolates from four poplar species in three Chinese regions and performed genome resequencing. An annotation of SNPs of MbMu indicated that the SNPs potentially have a functional effect on 69.2% of the predicted genes. Using the SNP dataset of nonredundant isolates, a structure and principal component analysis revealed that MbMu and MbMo belong to two genetically distinct populations. By contrast, subpopulation structures could not be found among MbMu isolates. A neighbor-net analysis and a homoplasy index test provided evidence of recombination among MbMu isolates. The short distance (109–174 bp) of linkage disequilibrium half-decay supported the presence of a high level of recombination in the MbMu population. The genetic architectures of the MAT loci of MbMu and MbMo were revealed by searching genome assemblies or by homology-based cloning, and a BLAST search verified each isolate carrying one of the two opposite MAT loci. This study revealed that the MbMu population contains a wide range of functional variants, shows high-frequency recombination, and exhibits heterothallic mating systems, indicating high evolutionary potential and a resultant threat to poplar plantations.

Realizing Valley-Polarized Energy Spectra in Bilayer Graphene Quantum Dots via Continuously Tunable Berry Phases

The Berry phase plays an important role in determining many physical properties of quantum systems. However, tuning the energy spectrum of a quantum system via Berry phase is comparatively rare because the Berry phase is usually a fixed constant. Here, we report the realization of an unusual valley-polarized energy spectra via continuously tunable Berry phases in Bernal-stacked bilayer graphene quantum dots. In our experiment, the Berry phase of electron orbital states is continuously tuned from about π to 2π by perpendicular magnetic fields. When the Berry phase equals π or 2π, the electron states in the two inequivalent valleys are energetically degenerate. By altering the Berry phase to noninteger multiples of π, large and continuously tunable valley-polarized energy spectra are realized. Our result reveals the Berry phase's essential role in valleytronics and the observed valley splitting, on the order of 10 meV at a magnetic field of 1 T, is about 100 times larger than Zeeman splitting for spin, shedding light on graphene-based valleytronics.

Magnetically tunable dual-band terahertz absorption based on guided-mode resonance

We propose a magnetically tunable dual-band terahertz (THz) absorber by using an InAs substrate with a subwavelength zero-contrast germanium grating. The results demonstrate that the absorption peaks in this absorber can be dynamically tuned by changing the intensity and the rotation angle of the applied transverse magnetic field, which is achievable at a moderate order of magnitude of 0.1 Tesla. In addition, we investigate the distribution of magnetic field intensity and find that the magnetically tunable absorption originates from the combination of the magneto-optical effect and the guided-mode resonance effect, where the absorption peaks shift in different directions at normal incidence and oblique incidence. Furthermore, the absorption intensity of the proposed structure could reach 99% with an ultra-high Q-factor of 258. This work paves the way for actively adjustable high-resolution THz absorption or a nonreciprocal thermal emitter.

Enhanced Near-Field Radiative Heat Transfer between Graphene/hBN Systems

Near-field radiative heat transfer (NFRHT) can exceed the blackbody radiation limit owing to the coupled evanescent waves, implying a significant potential for energy conversion and thermal management. Coupled surface plasmon polaritons (SPPs) and hyperbolic phonon polaritons (HPPs) with small ohmic losses enable a long propagation wavelength that is essential in NFRHT. However, so far, there still lacks knowledge about the experimental investigation of the coupling of SPPs and HPPs in terms of NFRHT. In this study, the NFRHT between graphene/hexagonal boron nitride (hBN) systems that can be readily transferred onto various substrates, with a gap space of ≈400 nm is measured. NFRHT enhancements in the order of three and six times higher than the blackbody limit for graphene/hBN heterostructures and graphene/hBN/graphene multilayers, respectively are demonstrated. In addition, the largest ever radiative heat flux using graphene/hBN/graphene multilayers under similar gap space of 400 nm is obtained. Consequently, analyzing the photon tunneling modes reveal that these phenomena are consequences of coupled SPPs of graphene and HPPs of hBN.

Lactobacillus plantarum HFY05 Attenuates Carrageenan-Induced Thrombosis in Mice by Regulating NF-κB Pathway-Associated Inflammatory Responses

In this study, a carrageenan-induced thrombus model was established in mice to observe the ability of Lactobacillus plantarum KFY05 (LP-KFY05) to inhibit thrombosis through an NF-κB-associated pathway. Biochemical analysis, microscopical observations, quantitative polymerase chain reactions (qPCR) and western blot analysis were used to examine relevant serum and tissue indexes, and the composition of intestinal microorganisms was determined by examining the abundance of microorganisms in feces. The results showed that LP-KFY05 could markedly reduce the degree of black tail in thrombotic mice; increase the activated partial thromboplastin time (APTT); and decrease the thrombin time (TT), fibrinogen (FIB) level, and prothrombin time (PT). LP-KFY05 could also reduce tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β) levels in sera and renal tissues of thrombotic mice. Hematoxylin and eosin staining showed that LP-KFY05 could alleviate renal tissue lesions and tail vein thrombosis. qPCR results showed that LP-KFY05 could down-regulate nuclear factor kappa-B (NF-κB) p65, IL-6, TNF-α, and interferon γ (IFN-γ) mRNA expression in renal tissues, as well as NF-κB p65, intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin mRNA expression in tail vein vascular tissues of thrombotic mice. Western blot analysis showed that LP-KFY05 also down-regulated NF-κB protein expression in renal and tail vein vascular tissues of thrombotic mice. Lastly, LP-KFY05 increased the abundances of Bacteroidetes, Lactobacillus, and Bifidobacterium, as well as decreased the abundance of Firmicutes. These results show that LP-KFY05 can reduce inflammation and inhibit thrombosis in thrombotic mice, and the effects of high concentrations of LP-KFY05 were most pronounced, which were similar to the effects of dipyridamole.

Comparison of Transperitoneal and Retroperitoneal Robotic Partial Nephrectomy for Patients With Complete Upper Pole Renal Tumors

OBJECTIVES

We compared the outcomes of transperitoneal robotic partial nephrectomy (TRPN) and retroperitoneal robotic partial nephrectomy (RRPN) for complete upper pole renal masses (1 point for the "L" component of the RENAL scoring system).

MATERIAL AND METHODS

We retrospectively reviewed patients who underwent either TRPN or RRPN from 2013 to 2016. Baseline demographics and perioperative, functional, and oncological results were compared. Multivariable analysis was performed to identify factors related to pentafecta achievement (ischemia time ≤25 min, negative margin, perioperative complication free, glomerular filtration rate (eGFR) preservation >90%, and no chronic kidney disease upstaging).

RESULTS

No significant differences between TRPN vs. RRPN were noted for operating time (110 vs. 114 min, p = 0.870), renal artery clamping time (19 vs. 18 min, p = 0.248), rate of positive margins (0.0% vs. 3.3%, p = 0.502), postoperative complication rates (25.0% vs. 13.3%, p = 0.140). TRPN was associated with a more estimated blood loss (50 vs. 40 ml, p = 0.004). There were no significant differences in pathologic variables, rate of eGFR decline for postoperative 12-month (9.0% vs. 7.1%, p = 0.449) functional follow-up. Multivariate analysis identified that only RENAL score (odd ratio: 0.641; 95% confidence interval: 0.455-0.904; p = 0.011) was independently associated with the pentafecta achievement.

CONCLUSIONS

For completely upper pole renal masses, both TRPN and RRPN have good and comparable results. Both surgical approaches remain viable options in the treatment of these cases.