18 research outputs found

    Programmable Polyproteams of Tyrosine Ammonia Lyases as Cross-Linked Enzymes for Synthesizing p-Coumaric Acid

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    Ideal immobilization with enhanced biocatalyst activity and thermostability enables natural enzymes to serve as a powerful tool to yield synthetically useful chemicals in industry. Such an enzymatic method strategy becomes easier and more convenient with the use of genetic and protein engineering. Here, we developed a covalent programmable polyproteam of tyrosine ammonia lyases (TAL-CLEs) by fusing SpyTag and SpyCatcher peptides into the N-terminal and C-terminal of the TAL, respectively. The resulting circular enzymes were clear after the spontaneous isopeptide bonds formed between the SpyTag and SpyCatcher. Furthermore, the catalytic performance of the TAL-CLEs was measured via a synthesis sample of p-Coumaric acid. Our TAL-CLEs showed excellent catalytic efficiency, with 98.31 ± 1.14% yield of the target product—which is 4.15 ± 0.08 times higher than that of traditional glutaraldehyde-mediated enzyme aggregates. They also showed over four times as much enzyme-activity as wild-type TAL does and demonstrated good reusability, and so may become a good candidate for industrial enzymes

    Direct Gene Expression Profile Prediction for Uveal Melanoma from Digital Cytopathology Images via Deep Learning and Salient Image Region Identification

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    Objective: To demonstrate that deep learning (DL) methods can produce robust prediction of gene expression profile (GEP) in uveal melanoma (UM) based on digital cytopathology images. Design: Evaluation of a diagnostic test or technology. Subjects, Participants, and Controls: Deidentified smeared cytology slides stained with hematoxylin and eosin obtained from a fine needle aspirated from UM. Methods: Digital whole-slide images were generated by fine-needle aspiration biopsies of UM tumors that underwent GEP testing. A multistage DL system was developed with automatic region-of-interest (ROI) extraction from digital cytopathology images, an attention-based neural network, ROI feature aggregation, and slide-level data augmentation. Main Outcome Measures: The ability of our DL system in predicting GEP on a slide (patient) level. Data were partitioned at the patient level (73% training; 27% testing). Results: In total, our study included 89 whole-slide images from 82 patients and 121 388 unique ROIs. The testing set included 24 slides from 24 patients (12 class 1 tumors; 12 class 2 tumors; 1 slide per patient). Our DL system for GEP prediction achieved an area under the receiver operating characteristic curve of 0.944, an accuracy of 91.7%, a sensitivity of 91.7%, and a specificity of 91.7% on a slide-level analysis. The incorporation of slide-level feature aggregation and data augmentation produced a more predictive DL model (P = 0.0031). Conclusions: Our current work established a complete pipeline for GEP prediction in UM tumors: from automatic ROI extraction from digital cytopathology whole-slide images to slide-level predictions. Our DL system demonstrated robust performance and, if validated prospectively, could serve as an image-based alternative to GEP testing

    Epidemiological and etiological characteristics of fever, thrombocytopenia and leukopenia syndrome in Henan Province, China, 2011-2012.

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    The Fever, Thrombocytopenia and Leukopenia Syndrome (FTLS) is caused by a bunyavirus known as the FTLS virus (FTLSV), which was recently discovered in China. We examined the epidemiological and etiological features of 637 laboratory-confirmed cases of FTLS with onset from January 2011 to December 2012 in Henan Province, China. The highest incidence of FTLS occurred between May and August: 76.5% of all laboratory-confirmed cases occurred during those four months. Of the laboratory-confirmed cases, 60.9% were in the 46-69 years old age groups; 96.1% (612/637) occurred in farmers; 98.1% (625/637) were reported from Xinyang Prefecture. During the same time period, 2047 cases were reported in China. The nucleotide and amino acid sequences of FTLSV strains identified during 2011-2012 in Henan Province were ≥ 96% identical. This findings provides insight for developing public-health interventions for the control and prevention of FTLS in epidemic area

    Mesoporous Cobalt Oxide (CoO<sub>x</sub>) Nanowires with Different Aspect Ratios for High Performance Hybrid Supercapacitors

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    Cobalt oxide (CoOx) nanowires have been broadly explored as advanced pseudocapacitive materials owing to their impressive theoretical gravimetric capacity. However, the traditional method of compositing with conductive nanoparticles to improve their poor conductivity will unpredictably lead to a decrease in actual capacity. The amelioration of the aspect ratio of the CoOx nanowires may affect the pathway of electron conduction and ion diffusion, thereby improving the electrochemical performances. Here, CoOx nanowires with various aspect ratios were synthesized by controlling hydrothermal temperature, and the CoOx electrodes achieve a high gravimetric specific capacity (1424.8 C g−1) and rate performance (38% retention at 100 A g−1 compared to 1 A g−1). Hybrid supercapacitors (HSCs) based on activated carbon anode reach an exceptional specific energy of 61.8 Wh kg−1 and excellent cyclic performance (92.72% retention, 5000 cycles at 5 A g−1). The CoOx nanowires exhibit great promise as a favorable cathode material in the field of high-performance supercapacitors (SCs)

    Metagenomic analysis of fever, thrombocytopenia and leukopenia syndrome (FTLS) in Henan Province, China: discovery of a new bunyavirus.

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    Since 2007, many cases of fever, thrombocytopenia and leukopenia syndrome (FTLS) have emerged in Henan Province, China. Patient reports of tick bites suggested that infection could contribute to FTLS. Many tick-transmitted microbial pathogens were tested for by PCR/RT-PCR and/or indirect immunofluorescence assay (IFA). However, only 8% (24/285) of samples collected from 2007 to 2010 tested positive for human granulocytic anaplasmosis (HGA), suggesting that other pathogens could be involved. Here, we used an unbiased metagenomic approach to screen and survey for microbes possibly associated with FTLS. BLASTx analysis of deduced protein sequences revealed that a novel bunyavirus (36% identity to Tehran virus, accession: HQ412604) was present only in sera from FTLS patients. A phylogenetic analysis further showed that, although closely related to Uukuniemi virus of the Phlebovirus genus, this virus was distinct. The candidate virus was examined for association with FTLS among samples collected from Henan province during 2007-2010. RT-PCR, viral cultures, and a seroepidemiologic survey were undertaken. RT-PCR results showed that 223 of 285 (78.24%) acute-phase serum samples contained viral RNA. Of 95 patients for whom paired acute and convalescent sera were available, 73 had serologic evidence of infection, with 52 seroconversions and 21 exhibiting a 4-fold increase in antibody titer to the virus. The new virus was isolated from patient acute-phase serum samples and named Henan Fever Virus (HNF virus). Whole-genome sequencing confirmed that the virus was a novel bunyavirus with genetic similarity to known bunyaviruses, and was most closely related to the Uukuniemi virus (34%, 24%, and 29% of maximum identity, respectively, for segment L, M, S at maximum query coverage). After the release of the GenBank sequences of SFTSV, we found that they were nearly identical (>99% identity). These results show that the novel bunyavirus (HNF virus) is strongly correlated with FTLS

    Monosubstituted ferrocene liquid crystals containing click triazole with a wide nematic phase temperature range

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    <p>New monosubstituted ferrocenomesogens of the 1,4-substituted-1,2,3-triazole series <b>3a-3d</b> and the 5-halogen-1,4-substituted-1,2,3-triazole series <b>4a-4d</b> were successfully synthesised through a facile and versatile synthetic route using click reactions with moderate yields, in different atmospheres, and catalysed by different amounts of CuX (X = Br, I). Two series of compounds exhibited a typical nematic liquid crystal texture, and the 5-halogen-1,4-substituted-1,2,3-triazole series <b>4</b> had a wider mesomorphic temperature range than the corresponding series <b>3</b> due to the effect of the halogen atom substituent on the triazole. These compounds showed similar absorption spectra, but the fluorescence emission spectra of <b>4</b> were obviously redshift relative to <b>3</b>. Cyclic voltammetry investigations revealed that the redox-active ferrocenyl groups of <b>3</b> and <b>4</b> follow one-electron transfer processes.</p

    Atomically precise single metal oxide cluster catalyst with oxygen-controlled activity

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    Single cluster catalysts (SCCs) consisting of atomically precise metal nanoclusters dispersed on supports represent a new frontier of heterogeneous catalysis. However, the ability to synthesize SCCs with high loading and to precisely introduce non-metal atoms to further tune their catalytic activity and reaction scope of SCCs have been longstanding challenges. Here, a new interface confinement strategy is developed for the synthesis of a high density of atomically precise Ru oxide nanoclusters (Ru3O2) on reduced graphene oxide (rGO), attributed to the suppression of diffusion-induced metal cluster aggregation. Ru3O2/rGO exhibits a significantly enhanced activity for oxidative dehydrogenation of 1,2,3,4-tetrahydroquinoline (THQ) to quinoline with a high yield (≈86%) and selectivity (≈99%), superior to Ru and RuO2 nanoparticles, and homogeneous single/multiple-site Ru catalysts. In addition, Ru3O2/rGO is also capable of efficiently catalyzing more complex oxidative reactions involving three reactants. The theoretical calculations reveal that the presence of two oxygen atoms in the Ru3O2 motif not only leads to a weak hydrogen bonding interaction between the THQ reactant and the active site, but also dramatically depletes the density of states near the Fermi level, which is attributed to the increased positive valence state of Ru and the enhanced oxidative activity of the Ru3O2 cluster for hydrogen abstraction.Agency for Science, Technology and Research (A*STAR)Ministry of Education (MOE)J.L. acknowledges the support from MOE grants (MOE2019-T2-2-044 and R-143-000-B47-114) and the support from Agency for Science, Technology and Research (A*STAR) under its AME IRG Grant (Project No. A20E5c0096) and NUS Green Energy Program. Y.Y.F thanks the support from National Natural Science Foundation of China (22005244) and Natural Science Foundation of Ningbo City (202003N4052)

    Map of Henan Province, showing laboratory-confirmed FTLS cases in 2011–2012.

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    <p>1 Shangcheng, 2 Guangshan, 3 Sihe), 4 Pingqiao, 5 Xinxian, 6 Luoshan, 7 Gushi, 8 Huangchuan, 9 Tongbai, 10 Xixian, 11 Queshan, 12 Luyi, 13 Zhengyang, 14 Dengfeng.</p
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