Bean pod mottle virus (BPMV) is a destructive virus that causes serious economic losses in many countries every year, highlighting the importance of its effective detection. In this study, we ...developed a fast reverse transcription-cross-priming amplification (RT-CPA) coupled with lateral flow dipstick (LFD) diagnostic method for BPMV detection. The RT-CPA-LFD assay that targets the coat protein gene of BPMV was highly specific against diagnosing four other common viruses transmitted by soybean seeds, i.e., Southern bean mosaic virus (SBMV), Tomato ringspot virus (ToRSV), Arabis mosaic virus (ArMV), and Tobacco ringspot virus (TRSV). The sensitivities of the real-time fluorescent RT-CPA and the RT-CPA-LFD assay were at least 50 pg/μl and 500 pg/μl, respectively. Despite a compromise in the limit of detection of the RT-CPA method compared with TaqMan-MGB real-time RT-PCR, our results demonstrated a notably better performance in the detection of field samples of BPMV-infested soybean seeds. With the advantages of efficiency and convenience by visual determination, the RT-CPA-LFD assay presents a potential application for the rapid and accurate detection of BPMV in routine tests.
Electronically matched nucleophilic 1,6‐conjugate addition has been well studied and widely applied in synthetic areas. In contrast, nucleophilic 1,5‐conjugate addition represents an electronically ...forbidden process and is considered unfeasible. Here, we describe modular protocols for 1,5‐conjugate addition reactions via palladium hydride catalysis. Both palladium and synergistic Pd/organocatalyst systems are developed to catalyze 1,5‐conjugate reaction, followed by inter‐ or intramolecular 3+2 cyclization. A migratory 1,5‐addition protocol is established to corroborate the feasibility of this umpolung concept. The 1,5‐addition products are conveniently transformed into a series of privileged enantioenriched motifs, including polysubstituted tetrahydrofuran, dihydrofuran, cyclopropane, cyclobutane, azetidine, oxetane, thietane, spirocycle and bridged rings. Preliminary mechanistic studies corroborate the involvement of palladium hydride catalysis.
An unconventional umpolung protocol was demonstrated for novel 1,5‐conjugate additions via palladium hydride catalyst. Three catalytic reaction modes including 1,5‐addition cascade with inter‐ and intramolecular 3+2 cyclization and migratory 1,5‐addition were established via palladium or palladium/organo‐cocatalysis.
The high intermediate (H*, OH*) energy barriers and slow mass/charge transfer increase the overpotential of alkaline water electrolysis at large‐current‐density. Engineering the electronic structure ...with the morphology of the catalyst to reduce energy barriers and improve mass/charge transportation is effective but remains challenging. Herein, a Ce‐doped CoP nanosheet is hybrid with Ni3P@NF (Ni foam) support to enhance mass/charge transfer, tune energy barriers, and improve water‐splitting kinetics through a synergistic activation. The engineered Ce0.2‐CoP/Ni3P@NF cathode exhibits an ultralow overpotential (η500, η1000) of −185, and −225 mV at −500 and −1000 mA cm−2 in 1.0 m KOH, along with an excellent pH‐universality. Impressively, an electrolyzer using the Ce0.2‐CoP/Ni3P@NF cathode can afford 500 mA cm−2 at a cell voltage of only 1.775 V and maintain stable electrolysis for 200 h in 25 wt% KOH (50 °C). Characterization and density functional theory calculation further reveal the Ce‐doping and CoP/Ni3P hybrid interaction synergistically downshift d‐band centers (εd = −2.0 eV) of Ce0.2‐CoP/Ni3P to the Fermi level, thereby activate local electronic structure for accelerating H2O dissociation and optimizing Gibbs free energy of hydrogen adsorption (∆GH*).
A highly efficient Ce0.2‐CoP/Ni3P@NF cathode is designed with a synergistic activation strategy. The Ce‐doping and CoP/Ni3P hybrid interactions synergistically enhance charge/mass transfer, engineering the local electronic structure to reduce energy barriers. Therefore, the Ce0.2‐CoP/Ni3P@NF exhibits an ultralow overpotential of 185 mV, 162 mV, 406 mV at −500 mA cm−2 in 1.0 m KOH, 0.5 m H2SO4, and 1.0 m PBS.
The extraordinary growth and progression of tumor require enormous nutrient and energy. Unregulated behaviors of cancer cell progressing and persistently change of tumor microenvironment (TME) which ...acts as the soil for cancer growth and metastasis are the ubiquitous features. The tumor microenvironment exhibits some unique features which differ with the normal tissues. While the nanoparticles get through the blood vessel leakage, they encounter immediately and interact directly with these microenvironment factors. These factors may inhibit the diffusion of nanoparticles from penetrating through the tumor, or induce the dissociation of nanoparticles. Different nanoparticles encountered with different intratumoral microenvironment factors end up in different way. Therefore, in this review, we first briefly introduced the formations, distributions, features of some intratumoral microenvironment, and their effects on the tumor progression. They include extracellular matrix (ECM), matrix metalloproteinases (MMPs), acidic/hypoxia environment, redox environment, and tumor associated macrophages (TAMs). We then exemplified how these factors interact with nanoparticles and emphasized the potentials and challenges of nanoparticle-based strategies facing in enhancing intratumoral penetration and tumor microenvironment remodeling. We hope to give a simple understanding of the interaction between these microenvironment factors and the nanoparticles, thus, favors the designing and constructing of more ideal functional nanoparticles.
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Magnetically controlled capsule endoscopy (MCE) has become an efficient diagnostic modality for gastric diseases. We developed a novel automatic gastric lesion detection system to assist in diagnosis ...and reduce inter-physician variations. This study aimed to evaluate the diagnostic capability of the computer-aided detection system for MCE images.
We developed a novel automatic gastric lesion detection system based on a convolutional neural network (CNN) and faster region-based convolutional neural network (RCNN). A total of 1,023,955 MCE images from 797 patients were used to train and test the system. These images were divided into 7 categories (erosion, polyp, ulcer, submucosal tumor, xanthoma, normal mucosa, and invalid images). The primary endpoint was the sensitivity of the system.
The system detected gastric focal lesions with 96.2% sensitivity (95% confidence interval CI, 95.7%-96.5%), 76.2% specificity (95% CI, 75.97%-76.3%), 16.0% positive predictive value (95% CI, 15.7%-16.3%), 99.7% negative predictive value (95% CI, 99.74%-99.79%), and 77.1% accuracy (95% CI, 76.9%-77.3%) (sensitivity was 99.3% for erosions; 96.5% for polyps; 89.3% for ulcers; 87.2% for submucosal tumors; 90.6% for xanthomas; 67.8% for normal; and 96.1% for invalid images). Analysis of the receiver operating characteristic curve showed that the area under the curve for all positive images was 0.84. Image processing time was 44 milliseconds per image for the system and 0.38 ± 0.29 seconds per image for clinicians (P < .001). The kappa value of 2 times repeated reads was 1.
The CNN faster-RCNN-based diagnostic program system showed good performance in diagnosing gastric focal lesions in MCE images.
Non-orthogonal multiple access (NOMA) has been recognized as a promising technique for providing high data rates in 5G systems. This letter is to study physical layer security in a single-input ...single-output (SISO) NOMA system consisting of a transmitter, multiple legitimate users and an eavesdropper. The aim of this letter is to maximize the secrecy sum rate (SSR) of the NOMA system subject to the users' quality of service (QoS) requirements. We firstly identify the feasible region of the transmit power for satisfying all users' QoS requirements. Then we derive the closed-form expression of an optimal power allocation policy that maximizes the SSR. Numerical results are provided to show a significant SSR improvement by NOMA compared with conventional orthogonal multiple access (OMA).
Direct position determination (DPD) approaches of non-circular (NC) signals for distributed antenna arrays are outstanding in location accuracy and available degrees of freedom. Nevertheless, the ...existing grid-based DPD approaches involve unnecessary computational costs because of NC phases. Besides, the cost function utilized in DPD could cause performance deterioration as ignoring the non-homogeneity error of the received data. To this end, we propose a DPD approach implemented by polynomial rooting and optimal weighting. Aiming to reduce computational costs, we first construct a computationally efficient cost function. Meanwhile, to mitigate the adverse impact induced by non-homogeneity errors in an effective manner, we assign an optimal weight to each antenna array. Simulation results demonstrate that the proposed approach achieves a good compromise between performance and computational complexity.
An efficient double catalytic system, combining chiral amine and 2-mercaptobenzoic acid, is applied for α',β-regioselective 4+2 annulations of 2-cyclopentenone with a diversity of activated alkenes, ...constructing multifunctional chiral bicycle2,2,1heptane scaffolds in good to excellent yields and enantioselectivities. In comparison with the traditional cross-dienamine species between 2-cyclopentenone and chiral amine, the interrupted enamine intermediate containing a covalently linked thiol catalyst shows significantly improved reactivity.
The use of new technologies to empower the social co-governance of food safety is a consensus in the theoretical and practical fields of food safety governance modernization. Based on the innovative ...features of the block chain such as non-tampering, consensus mechanism, and a smart contract, this paper proposes a new method to facilitate the achievement of the effect of social co-governance of food safety. Firstly, it provides a profound analysis of the causes of food safety problems and the drawbacks of traditional centralized supervision, and proposes a solution with decentralized features and the design process of smart contracts to realize the chaining and integration of finite credible data in the process of food circulation; secondly, it constructs a mathematical model through finite credible data on the chain and obtains the probabilistic consensus results of food safety through rigorous derivation; Finally, the scheme, model and algorithm are effectively practiced through the experimental environment of mature block chain platform and provincial food supervision platform. The example shows that the market failure problem in food safety can be greatly alleviated by the non-tampering feature of block chain; the consensus results formed by the credible data uploading, model construction and data derivation through smart contracts can greatly alleviate the problem of involution of government administrative supervision; and the social co-governance capacity of food safety can be improved through information sharing with the active synergy of multiple subjects of co-governance.
Atropisomerism, an expression of axial chirality caused by limited bond rotation, is a prominent aspect within the field of medicinal chemistry. It has been shown that atropisomers of a wide range of ...compounds, including established FDA-approved drugs and experimental molecules, display markedly different biological activities. The time-dependent reversal of chirality in atropisomers poses complexity and obstacles in the process of drug discovery and development. Nonetheless, recent progress in understanding atropisomerism and enhanced characterization methods have greatly assisted medicinal chemists in the effective development of atropisomeric drug molecules. This article provides a comprehensive review of their special design thoughts, synthetic routes, and biological activities, serving as a reference for the synthesis and biological evaluation of bioactive atropisomers in the future.
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![Asymmetric [4+2] annulation...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/1359-7345/small "Asymmetric [4+2] annulations to construct norcamphor scaffolds with 2-cyclopentenone via double amine-thiol catalysis")
