Regiodivergent Arylation of Pyridines via Zincke Intermediates.

An arylation protocol for pyridines is described, via the ring-opened Zincke intermediate. Treatment of pyridines with triflic anhydride and a secondary amine produces an azahexatriene species, which undergoes regioselective Pd-catalyzed arylation at the putative C4 position. Recyclization then provides the pyridine products. Alternatively, metal-free arylation with a diaryliodonium salt is selective for the pyridine meta-position, affording a regiodivergent approach to pyridine biaryls from a common intermediate.

Photonic Spin Hopfions and Monopole Loops.

Spin textures with various topological orders are of great theoretical and practical interest. Hopfion, a spin texture characterized by a three-dimensional topological order was recently realized in electronic spin systems. Here, we show that monochromatic light can be structured such that its photonic spin exhibits a hopfion texture in the three-dimensional real space. We also provide ways to construct spin textures of arbitrary Hopf charges. When extending the system to four dimensions by introducing a parameter dimension, a new type of topological defect in the form of a monopole loop in photonic spin is encountered. Each point on the loop is a topological spin defect in three dimensions, and the loop itself carries quantized Hopf charges. Such photonic spin texture and defect may find application in control and sensing of nanoparticles, and optical generation of topological texture in motions of particles or fluids.

A Underwater Sequence Image Dataset for Sharpness and Color Analysis.

The complex underwater environment usually leads to the problem of quality degradation in underwater images, and the distortion of sharpness and color are the main factors to the quality of underwater images. The paper discloses an underwater sequence image dataset called TankImage-I with gradually changing sharpness and color distortion collected in a pool. TankImage-I contains two plane targets, a total of 78 images. It includes two lighting conditions and three different water transparency. The imaging distance is also changed during the photographing process. The paper introduces the relevant details of the photographing process, and provides the measurement results of the sharpness and color distortion of the sequence images. In addition, we verify the performance of 14 image quality assessment methods on TankImage-I, and analyze the results of 14 image quality assessment methods from the aspects of sharpness and color, which provides a reference for the design and improvement of underwater image quality assessment algorithm and underwater imaging system design.

Isotropic topological second-order spatial differentiator operating in transmission mode.

Differentiation has widespread applications, particularly in image processing for edge detection. Significant advances have been made in using nanophotonic structures and metamaterials to perform such operations. In particular, a recent work demonstrated a topological differentiator in which the transfer function exhibited a topological charge, making the differentiation operation robust to variations in operating conditions. The demonstrated topological differentiator, however, operates in reflection mode at off-normal incidence and is difficult to integrate into compact imaging systems. In this work, we design a topological differentiator that operates isotropically in transmission mode at normal incidence. The device exhibits an optical transfer function with a symmetry-protected topological charge of ±2 and performs second-order differentiation. Our work points to the potential of harnessing topological concepts for optical computing applications.

Universal Behavior of the Scattering Matrix Near Thresholds in Photonics.

Scattering thresholds and their associated spectral square root branch points are ubiquitous in photonics. In this Letter, we show that the scattering matrix has a simple universal behavior near scattering thresholds. We use unitarity, reciprocity, and time-reversal symmetry to construct a two-parameter model for a two-port scattering matrix near a threshold. We demonstrate this universal behavior in three different optical systems, namely, a photonic crystal slab, a planar dielectric interface, and a junction between metallic waveguides of different widths.

PT-Symmetric Topological Edge-Gain Effect.

We demonstrate a non-Hermitian topological effect that is characterized by having complex eigenvalues only in the edge states of a topological material, despite the fact that the material is completely uniform. Such an effect can be constructed in any topological structure formed by two gapped subsystems, e.g., a quantum spin-Hall system, with a suitable non-Hermitian coupling between the spins. The resulting complex-eigenvalued edge state is robust against defects due to the topological protection. In photonics, such an effect can be used for the implementation of topological lasers, in which a uniform pumping provides gain only in the edge lasing state. Furthermore, such a topological lasing model is reciprocal and is thus compatible with standard photonic platforms.

New tranylcypromine derivatives containing sulfonamide motif as potent LSD1 inhibitors to target acute myeloid leukemia: Design, synthesis and biological evaluation.

Lysine-specific demethylase 1 (LSD1) is frequently elevated in acute myeloid leukemia (AML) and often leads to tumorigenesis. In recent years, numerous LSD1 inhibitors based on tranylcypromine (TCP) scaffolding have reached clinical trials. Most TCP derivatives were modified at the amino site of cyclopropane motif. Herein, we for the first time introduced a sulfonamide group in TCP benzene ring of series a compounds and performed a systematical study on structure and activity relationships by varying sulfonamide groups. The introduction of sulfonamide significantly increased the targeting capacity of TCP against LSD1. Moreover, we discovered that the Boc attached LSD1 inhibitors (labelled as series b compounds) substantially improved their anti-proliferation capacity towards AML cells. The intracellular thermal shift and LC-MS/MS results implied that Boc enhanced the drug lipophilicity and might be removed under the cancerous acidic environment to release the real pharmacophore, evidenced by the fact that a structurally similar but acidic inert pivaloyl to replace Boc dramatically dropped the cellular anti-proliferation effect. Finally, a benzyl group installed at the amino site to appropriately increase lipophilicity led to trans-4-(2-(benzylamino)-cyclopropyl)-N,N-diethylbenzenesulfonamide a10 that showed better anti-proliferation activity in AML cells and enzymatic inhibition against LSD1. Taken together, our work offers a novel TCP-based structure and provides a prodrug strategy for the discovery of potent LSD1 inhibitors by having appropriate lipophilicity.

Serum Exosomes from Newborn Piglets Restrict Porcine Epidemic Diarrhea Virus Infection.

Exosomes are vehicles in the body fluid that participate in many biological processes, especially immune responses. In this study, we employed comparative proteome analysis to investigate the roles of serum exosomes during viral infection in neonates using porcine epidemic diarrhea virus (PEDV), a devastating enteric virus in newborn piglets, as a model virus. Serum exosomes were first isolated from newborn piglets infected with PEDV or mock-infected newborn piglets, followed by label-free LC-MS/MS-based comparative quantitative proteomic analysis. Among the 441 detected proteins, 10 complement proteins were found in the serum exosomes, and significantly decreased expression levels of the C3, C6, and CFB complements were measured in PEDV-infected serum exosomes compared to those in mock-infected serum exosomes. After confirmation by Western blot, we then investigated the function of these exosomes in PEDV infection and discovered that exosomes from mock-infected newborn piglets restricted PEDV infection. However, this inhibition disappeared after the exosomes were heat-inactivated, suggesting that complements are key antiviral molecules. Our findings improve the understanding of antiviral responses mediated by exosomes in neonatal piglets and facilitate the discovery of novel antiviral drugs.

Dynamics for encircling an exceptional point in a nonlinear non-Hermitian system.

We study the dynamics near an exceptional point in a nonlinear non-Hermitian system consisting of a pair of resonators. One of the resonators has a linear loss, and the other resonator has a saturable gain. We show that the system dynamics exhibit chiral characteristics. And moreover, unique to the nonlinear system, such dynamics allow one to adiabatically switch between bistable states at the same system parameter. Such bistable switching is potentially interesting in optical memory based on coupled laser systems.

Relayed Regioselective Alkynylation/Olefination of Unsymmetrical Cyclic Diaryliodonium Species Catalyzed by Cu and Pd: Affording Fluorescent Cytotoxic Benzoxazoles.

Although cyclic diaryliodonium species have the potential to act as valuable synthons for cascade transformations, they still remain largely unexplored. The regioselectivity associated with unsymmetrical cyclic diaryliodonium species has previously been known to pose a challenge. A regioselective relayed alkynylation and olefination of unsymmetrical cyclic diaryliodonium species has been achieved by installation of a directing amido group. These relayed transformations were delayed until an oxazole ring had formed, delivering a series of unique fluorescent benzoxazoles. Moreover, some of these synthetic benzoxazoles showed apparent inhibitory activity against malignant cancer cells. Further confocal visualization revealed that benzoxazoles targeted cell nuclei. These findings might provide a novel structural scaffold to develop desirable anticancer agents.

Pd catalyzed insertion of alkynes into cyclic diaryliodoniums: a direct access to multi-substituted phenanthrenes.

Cyclic diaryliodoniums remain unexplored compared to linear iodoniums. In our current work, internal alkynes were for the first time applied to react with cyclic iodoniums, catalyzed by Pd, resulting in a [4 + 2] benzannulation. Our work offers a new strategy to synthesize multi-substituted phenanthrene derivatives which are not easily accessed by conventional methods.

Application of multimodality perception scene construction based on Internet of Things (IoT) technology in art teaching.

Numerous impediments beset contemporary art education, notably the unidimensional delivery of content and the absence of real-time interaction during instructional sessions. This study endeavors to surmount these challenges by devising a multimodal perception system entrenched in Internet of Things (IoT) technology. This system captures students' visual imagery, vocalizations, spatial orientation, movements, ambient luminosity, and contextual data by harnessing an array of interaction modalities encompassing visual, auditory, tactile, and olfactory sensors. The synthesis of this manifold information about learning scenarios entails strategically placing sensors within physical environments to facilitate intuitive and seamless interactions. Utilizing digital art flower cultivation as a quintessential illustration, this investigation formulates tasks imbued with multisensory channel interactions, pushing the boundaries of technological advancement. It pioneers advancements in critical domains such as visual feature extraction by utilizing DenseNet networks and voice feature extraction leveraging SoundNet convolutional neural networks. This innovative paradigm establishes a novel art pedagogical framework, accentuating the importance of visual stimuli while enlisting other senses as complementary contributors. Subsequent evaluation of the usability of the multimodal perceptual interaction system reveals a remarkable task recognition accuracy of 96.15% through the amalgamation of Mel-frequency cepstral coefficients (MFCC) speech features with a long-short-term memory (LSTM) classifier model, accompanied by an average response time of merely 6.453 seconds-significantly outperforming comparable models. The system notably enhances experiential fidelity, realism, interactivity, and content depth, ameliorating the limitations inherent in solitary sensory interactions. This augmentation markedly elevates the caliber of art pedagogy and augments learning efficacy, thereby effectuating an optimization of art education.

Research on 3D virtual vision matching based on interactive color segmentation.

Given the prevalent issues surrounding accuracy and efficiency in contemporary stereo-matching algorithms, this research introduces an innovative image segmentation-based approach. The proposed methodology integrates residual and Swim Transformer modules into the established 3D Unet framework, yielding the Res-Swim-UNet image segmentation model. The algorithm estimates the disparateness of segmented outputs by employing regression techniques, culminating in a comprehensive disparity map. Experimental findings underscore the superiority of the proposed algorithm across all evaluated metrics. Specifically, the proposed network demonstrates marked improvements, with IoU and mPA enhancements of 2.9% and 162%, respectively. Notably, the average matching error rate of the algorithm registers at 2.02%, underscoring its efficacy in achieving precise stereoscopic matching. Moreover, the model's enhanced generalization capability and robustness underscore its potential for widespread applicability.

Repair of a "long and narrow" skin defect of the upper extremity with a modified design of a compound SCIP flap: a series of 12 cases.

BACKGROUND: Large skin lesions of the upper extremity tend to be ''long and narrow'' in shape, and the currently used repair and reconstruction protocols still have some drawbacks, including difficulty in closure of the donor area, poor cosmetic appearance of the donor and recipient areas, and low flap survival rates. The ilioinguinal flap has been more widely used for repair and reconstruction of various complex conditions. In order to improve the versatility of the flap design and to achieve better aesthetic results, we report a study on the improved design of Compound SCIP flap for repairing "long and narrow" large skin defects of the upper extremity by using a modified design of the ilioinguinal flap for the procurement of perforating blood vessels and flap excision. METHODS: From April 2005 to August 2015, a total of 12 patients underwent this modified design procedure, in which the anterior branch of the fourth lumbar artery or the posterior intercostal artery was selected to provide blood supply for the perforator flap together with the superficial branch of the superficial iliac artery to meet the blood supply needs of the flap for the one-time repair of a large "long and narrow" skin defect in the upper limb. Patient demographics, flap characteristics, and associated complications were retrospectively analyzed. RESULTS: 3 females and 9 males were included in this study, the mean age of the patients was 31.7 years (range, 22-44 years), the mean follow-up period was 15.3 ± 5.6 months (range, 7-24 months), and all patients had complete closure of the defect site and donor area, and all flaps survived. CONCLUSIONS: The Compound SCIP flap presents some advantages in repairing 'long and narrow' skin defects in the upper limb. While ensuring the survival rate of the elongated ilioinguinal flap, it amplifies the benefits of the ilioinguinal flap and enhances skin utilization. This can serve as a beneficial choice for repairing 'long and narrow' skin defects in the upper limb.

LINC02257 regulates colorectal cancer liver metastases through JNK pathway.

Background: Long noncoding RNAs (lncRNAs) have emerged as critical regulators of colorectal cancer (CRC) progression, but their roles and underlying mechanisms in colorectal cancer liver metastases (CRLMs) remain poorly understood. Methods: To explore the expression patterns and functions of lncRNAs in CRLMs, we analyzed the expression profiles of lncRNAs in CRC tissues using the TCGA database and examined the expression patterns of lncRNAs in matched normal, CRC, and CRLM tissues using clinical samples. We further investigated the biological roles of LINC02257 in CRLM using in vitro and in vivo assays, and verified its therapeutic potential in a mouse model of CRLM. Results: Our findings showed that LINC02257 was highly expressed in metastatic CRC tissues and its expression was negatively associated with overall survival. Functionally, LINC02257 promoted CRC cell growth, migration, metastasis, and inhibited cell apoptosis in vitro, and enhanced liver metastasis in vivo. Mechanistically, LINC02257 up-regulated phosphorylated c-Jun N-terminal kinase (JNK) to promote CRLM. Conclusions: Our study revealed that LINC02257 played a key role in the proliferation and metastasis of CRC cells through the LINC02257/JNK axis. Targeting this axis may represent a promising therapeutic strategy for the treatment of liver metastases in patients with CRC.

[Optimizing the method for 31P-NMR analysis of organic phosphorus from wetland sediments].

Solution 31P-Nuclear Magnetic Resonance (NMR) is an analysis technology which has been an effective means for the analysis of environmental organic phosphorus. However, the method is rarely applied in the study of wetlands so that the corresponding researches about wetland sediment sample preparation method also very deficient. The present study was aimed to find the most suitable sample preparation method for 31P-NMR analysis of the artificial wetland sediments, using different extractant (NaOH or 0.25 mol x L(-1) NaOH + 0.05 mol x L(-1) EDTA as main extractant, and 1M HCl as pre-extractant or not), sample to extractant ratio (1 : 8 or 1 : 10), centrifugation conditions and scans time and so on. The results showed that the best 31P-NMR spectrum could be obtained with freeze-ried, ground and sieved sediments, 1M HCl as pre-extractant for 16 h, NaOH + 0.05 mol x L(-1) EDTA as main extractant for 16 h, extraction ratio of 1 : 8, and low temperature and high-speed centrifugation (4 degrees C, 10 000 r x min(-1) for 30 min) for avoiding hydrolysis of certain components. Besides, choosing much longer NMR scan time, as 14-16 h (scans about 25 000 times), could get more complete spectral signals spectrum. And finally, four kinds of P-compounds (orthophosphate, orthophosphate monoesters, orthophosphate diesters and pyrophosphate) were detected in the NMR spectrum. But neither polyphosphate nor phosphonates was not found in all these experiments, which need further study. Compared with the traditional chemical analysis method, 31P-NMR method of sample preparation is relatively simple. Then it is less destructive with components distinguished completely. Using 31P-NMR technology, the cognition of wetland phosphorus cycle, especially organophosphate, will be expected to get new breakthrough.

Smoke dispersion test and emergency control plan of fire in mine roadway during downward ventilation.

To explore the wind flow turbulence and smoke flow diffusion law during the mine downward ventilation fire, two similar experimental platforms of a inclined single pipe test device and a loop system multiple pipe test device were built. The change data of the air flow in the pipeline during the fire period under different air volumes were measured. The evolution process of downward ventilation fire in the whole roadway network domain in Dayan Mine was simulated, and the emergency plan was put forward. The results show that in the experiment, the combustion intensity of the fire source is positively correlated with the ventilation power, and the fire wind pressure increases with the increase of the inclination angle of the pipeline. The throttling effect of the fire area and the combustion of the fire source together make the air volume in the pipeline change rapidly. The critical wind speed that makes the downward ventilation flow fire wind pressure equal to the fan power is 1.8 m s-1. The stronger the fan capacity, the stronger the ability of the main air path to overcome the resistance of the fire zone and maintain the original state. In the simulation, the most dangerous place when the downward ventilation fire smoke is reversed is the area (weak flow area) in the mine tunnel network where the ventilation power is weaker than the fire wind power. This study can provide a theoretical basis for the formulation of emergency plans for mine fire accidents.

Construction of a TiO2/BiOCl heterojunction for enhanced solar photocatalytic oxidation of nitric oxide.

TiO2/BiOCl heterojunction photocatalysts with different molar ratios (Ti : Bi) were synthesized by a simple solvothermal method. Various spectroscopic techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), nitrogen adsorption-desorption, X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) and UV-Vis diffuse reflectance spectroscopy (UV-vis DRS) were used to characterize the prepared photocatalysts. The photocatalytic activity of the catalysts was investigated by removing low concentrations of nitrogen oxides. The characterization results show that the TiO2/BiOCl composite photocatalyst exhibits superior visible light response performance than pure BiOCl and TiO2. The optimized TiO2/BiOCl heterojunction with a Ti : Bi molar ratio of 4 : 1 has the best photocatalytic performance. The removal rate of nitrogen oxides of the composite photocatalyst can reach 75%, which is 2.34 times higher than that of pure BiOCl. The observed photocatalytic degradation activity of nitrogen oxides outperforms current state-of-the-art functional photocatalysts. The TiO2/BiOCl composite photocatalyst has a larger specific surface area, stronger visible light absorption and higher charge separation efficiency compared to other control samples, which contribute to the enhanced photocatalytic activity. The experimental results indicate that the combination of TiO2 with BiOCl is a promising technique to design visible light-responsive photocatalysts.

Spatio-temporal evolution law of gas-temperature coupling field in "110 method" goaf and prevention of spontaneous combustion.

To investigate the distribution characteristics of spontaneous combustion disaster (SCD) zones in the goaf of "110" mining method with U + L ventilation system and formulate corresponding fire prevention measures, enclosed coal oxidation experiments were carried out to measure the oxidation characteristics of Dongrong Coal Mine bituminous coal sample. A coupled 3DEC-CFD (3 dimensional Distinct Element Code) model was established. The 3D transient distribution characteristics of SCD zones in the "110" mining goaf under U+L ventilation condition were analyzed. Nitrogen injection in the tailgate was proposed for coal spontaneous combustion prevention. The results show that air leakage changed the distribution of oxygen and temperature fields in the "110" goaf, causing the region 20~60 m parallel to the retained roadway to remain in the oxidation zone for spontaneous combustion. As the working face advanced, the area change curve of SCD zones in the "110" goaf exhibited a "double inflection point" pattern. Eliminating the "retained roadway oxidation zone" can effectively reduce the spontaneous combustion risks in the "110" goaf and ensure mining safety. This study enriches the mechanisms of coal spontaneous combustion.

4-[(Z)-(n-Butyl-amino)(phenyl)methyl-idene]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one.

The title compound, C(21)H(23)N(3)O, exists in an enamine-keto form with the amino group involved in an intra-molecular N-H⋯O hydrogen bond. The dihedral angle between the phenyl rings is 73.59 (6)°. The five-membered ring is nearly planar, the largest deviation being 0.0004 (7) Å, and makes dihedral angles of 4.81 (6) and 69.81 (5)° wth the phenyl rings. In the crystal, pairs of weak C-H⋯O inter-actions link the mol-ecules into centrosymmetric dimers.