Smartphone-assisted nanozyme sensor array constructed based on reaction kinetics for the discrimination and identification of phenolic compounds.

Although the research on nanozymes has attracted widespread attention in recent years, the development of highly active and multifunctional nanozymes remains a challenge. Here, a bifunctional AMP-Cu nanozyme with laccase- and catecholase-like activities was successfully prepared at room temperature with Cu2+ as the metal ion and adenosine-5'-monophosphate (AMP) as the ligand molecule. Based on the excellent catalytic performance of AMP-Cu, a three-channel colorimetric sensor array was constructed using reaction kinetics as the sensing unit to achieve high-throughput detection and identification of six common phenolic compounds at low concentrations. This strategy simplifies the construction of sensor array and demonstrates the capacity to obtain multidimensional data from a single material. Finally, with the assistance of smartphones and homemade dark boxes, a portable on-site detection method for phenolic compounds was developed. This work would contribute to the development of portable sensors and the highly efficient identification of phenolic compounds in complex samples.

Synthesis, molecular docking, and binding Gibbs free energy calculation of ß-nitrostyrene derivatives: Potential inhibitors of SARS-CoV-2 3CL protease.

The outbreak of novel coronavirus disease 2019 (COVID-19), caused by the novel coronavirus (SARS-CoV-2), has had a significant impact on human health and the economic development. SARS-CoV-2 3CL protease (3CLpro) is highly conserved and plays a key role in mediating the transcription of virus replication. It is an ideal target for the design and screening of anti-coronavirus drugs. In this work, seven ß-nitrostyrene derivatives were synthesized by Henry reaction and ß-dehydration reaction, and their inhibitory effects on SARS-CoV-2 3CL protease were identified by enzyme activity inhibition assay in vitro. Among them, 4-nitro-ß-nitrostyrene (compound a) showed the lowest IC50 values of 0.7297 µM. To investigate the key groups that determine the activity of ß-nitrostyrene derivatives and their interaction mode with the receptor, the molecular docking using the CDOCKER protocol in Discovery Studio 2016 was performed. The results showed that the hydrogen bonds between ß-NO2 and receptor GLY-143 and the π-π stacking between the aryl ring of the ligand and the imidazole ring of receptor HIS-41 significantly contributed to the ligand activity. Furthermore, the ligand-receptor absolute binding Gibbs free energies were calculated using the Binding Affinity Tool (BAT.py) to verify its correlation with the activity of ß-nitrostyrene 3CLpro inhibitors as a scoring function. The higher correlation(r2=0.6) indicates that the absolute binding Gibbs free energy based on molecular dynamics can be used to predict the activity of new ß-nitrostyrene 3CLpro inhibitors. These results provide valuable insights for the functional group-based design, structure optimization and the discovery of high accuracy activity prediction means of anti-COVID-19 lead compounds.

Bioinformatic Prediction and Production of Four Recombinant Proteins from Different Developmental Stages of Trichinella spiralis and Testing of Their Diagnostic Sensitivity in Mice.

BACKGROUND: Trichinellosis is a serious food-borne parasitic zoonosis, thus finding high quality antigens is the key to serodiagnosis of trichinosis. This article reports the characterization and sensitivity of four recombinant proteins expressed by four genes (Wn10, Zh68, T668, and Wm5) from different developmental stages of Trichinella spiralis for the diagnosis of trichinellosis in mice. METHODS: This study was conducted in Jilin University and National Institute of Parasitic Diseases of Chinese Center for Disease Control and Prevention in 2017-2018. The structures and functions of the proteins encoded by four genes were predicted by bioinformatics analysis. The four genes were cloned and expressed, and the recombinant proteins were purified. Anti-Trichinella IgM and IgG antibodies in the sera of mice infected with T. spiralis from 1-45 d post-infection (dpi) were evaluated by ELISA. RESULTS: The optimal antigen epitopes of four proteins (P1, P2, P3, and P4) encoded by the four genes from T- and B-cells were predicted, and four purified recombinant proteins (r-P1, r-P2, r-P3, and r-P4) were successfully produced. For IgM, the antibody levels detected by the four recombinant antigens were approximately equal to the cut-off value. Anti-Trichinella IgG antibodies were first detected by r-P1 at 8 dpi, followed by r-P2, r-P3, and r-P4 at 10 dpi, 14 dpi, and 16 dpi, respectively, and the antibody levels remained high until 45 dpi. CONCLUSION: The recombinant antigens r-P1, r-P2, r-P3, and r-P4 could be antigens that react with antibodies, they showed high sensitivity in the detection of anti-Trichinella IgG antibodies in mice. Among these proteins, r-P1 may be a candidate antigen for the detection of anti-Trichinella IgG antibodies in the early infection phase and exhibited the best sensitivity among the antigens.

Intramolecular Diels-Alder Cycloaddition Approach toward the cis-Fused Δ5,6-Hexahydroisoindol-1-one Core of Cytochalasins.

Synthesis of the cis-fused Δ5,6-hexahydroisoindol-1-one core of cytochalasins B2-B5, K, Z8, Z9, Z12-Z15, and Z17 has been established starting from an intramolecular Diels-Alder reaction of the amide-tethered (8 E)-1,3,8-nonatriene. The trans-fused 5/6-bicyclic adduct was then subjected to highly stereoselective C9-ß-hydroxylation and epimerization of the C7-α-OH group.

[Intracranial atherosclerotic middle cerebral arterial stenosis research based on 3.0 Tesla high-resolution magnetic resonance imaging: recent progress].

Intracranial atherosclerotic disease (ICAD) of a major intracranial artery, including middle cerebral artery (MCA),basilar artery, is the most common causes of stroke and is associated with a high risk of recurrent stroke in China. The difficulty to treatment these high-risk disease is to identify high-risk stroke subgroups and to develop more effective treatments (aggressive medical therapy/endovascular therapy). With the benefits, including non-invasive, in vivo, and no-ionizing radiation, 3.0 Tesla high-resolution magnetic resonance imaging (HR MRI) could be used to stratify high-risk patients, monitor progression of disease, and evaluate clinical efficacy, based on MCA wall structure and plaque characteristic. HR MRI has the latency of predicting high-risk patients benefit from endovascular therapy, having a broad application prospect during psot-SAMMPRIS era. The current research on MCA stenosis using HR MRI focuses on methodoiogy, diagnosis and differential diagnosis, etiology, and lacks of clinical efficiency evaluation and prognostic analysis of ICAD treatment, especially lacks the research on in-stent restenosis, which needs further investigation.

[Inter- and intra-observer reproducibility of 3.0 T high-resolution magnetic resonance imaging for evaluating atherosclerotic stenosis in the middle cerebral artery].

OBJECTIVE: To assess the reproducibility of 3.0 T high-resolution magnetic resonance imaging (HR MRI) for evaluation of atherosclerotic stenosis in the middle cerebral artery (MCA). METHODS: From February, 2011 to December, 2013, 66 consecutive patients with MCA-M1 atherosclerotic stenosis (50%-99%) confirmed by digital subtractive angiography (DSA) received examinations with 3.0 T HR MRI for measurement of the vessel area (VA) and lumen area (LA) at the maximum narrow site (VA(narrow) and LA(narrow)) and the reference site (VA(reference) and LA(reference)) as well as the plaque distribution (ventral, dorsal, superior, and inferior). Two independent readers reviewed all the images and one reader reevaluated these images 4 weeks later. The inter- and intra-observer reproducibility was evaluated using the intraclass correlation coefficient (ICC). RESULTS: The measurements of VA(narrow), VA(reference), and LA(reference) using HR MRI showed excellent inter- (ICC=0.801, 0.843, and 0.808, respectively) and intra-observer reproducibility (ICC=0.811, 0.916, and 0.958, respectively), but the measurement of LA(narrow) had only moderate inter- and intra-observer reproducibility (ICC=0.584 and 0.625, respectively). For plaque distribution analysis (ventral, dorsal, superior, and inferior plaques), HR MRI also showed excellent inter- (ICC=0.856, 0.836, 0.791, and 0.905, respectively) and intra-observer reproducibility (ICC=0.876, 0.827, 0.825, and 0.950, respectively). CONCLUSION: HR MRI shows good inter- and intra-observer reproducibility in identifying MCA-M1 atherosclerotic plaque distribution and vessel and lumen measurements, but its reliability for lumen area measurement at the maximum narrowing site needs to be improved.

China's growing contribution to global intracranial aneurysm research (1991-2012): a bibliometric study.

BACKGROUND: We sought to analyze the growing worldwide trends of intracranial aneurysm research, investigate China's recent contribution, and compare the contributions of mainland China, Taiwan, and Hong Kong. METHODS: Global and China intracranial aneurysm-related publications were retrieved from the Web of Science database from 1991 to 2012. Excel 2007, Matlab, and Thomson Data Analyzer (TDA) software were used to analyze the search results for number of publications, cited frequency, h-index, and organization contributions. RESULTS: 16468 global papers were identified that were cited 273500 times until 2013-08-15. The United States accounted for 31.497% of the articles, 58.64% of the citations, and the highest h-index (127). Japan and Germany followed in frequency. China's articles ranked eighth (third in 2012) in total number, with most of the contributions occurring since 2002 (91.33%). China was at the early stage of the logic growth curve (exponential growth), with the citation frequency and h-index per year increasing. The quality of the publications was low. The main research centers were located in Beijing, Shanghai, Taiwan, and Hong Kong. The main Asian funding body was the National Natural Science Foundation of China. The number of publications and frequency of citations of papers from mainland China was greater than that of Taiwan or Hong Kong. CONCLUSION: Global intracranial aneurysm research has been developing swiftly since 1991, with the United States making the largest contribution. Research in China started later, in 2002. Since then, China has increased its rate of publication, and became the third largest contributor by 2012.

[Toll-like receptor 4: the potential therapeutic target for neuropathic pain].

Activation of microglia plays a vital role in the initiation and maintenance of specific neuropathic pain states. By activating microglia in central nervous system, Toll-like receptor 4 (TLR4) can promote the release of proinflammatory cytokines and neuroactive compounds, participate in the initiation and maintenance of neuropathic pain, and trigger the opiate side effects. Therefore, TLR4 may be a potential therapeutic target for neuropathic pain. Inhibition of TLR4 has shown some biological effects in neuropathic pain models and ibudilast (the TLR4 pathway-inhibiting agent) has been approved for for phase 2 clinical trials. This article briefly reviews the structure, function, and mechanism of TLR4 as well as the development of TLR4-targeted drugs.

N-Cyclo-hexyl-2-oxo-2-phenyl-acetamide.

In the title compound, C(14)H(17)NO(2), the two carbonyl groups are oriented with respect to each other with a torsion angle of -129.9 (3)°. The cyclo-hexane ring adopts a chair conformation. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds into a chain running along the a axis.