45 results on '"Xiang HY"'
Search Results
2. Comprehensive hepatotoxicity prediction: ensemble model integrating machine learning and deep learning.
- Author
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Khan MZI, Ren JN, Cao C, Ye HY, Wang H, Guo YM, Yang JR, and Chen JZ
- Abstract
Background: Chemicals may lead to acute liver injuries, posing a serious threat to human health. Achieving the precise safety profile of a compound is challenging due to the complex and expensive testing procedures. In silico approaches will aid in identifying the potential risk of drug candidates in the initial stage of drug development and thus mitigating the developmental cost., Methods: In current studies, QSAR models were developed for hepatotoxicity predictions using the ensemble strategy to integrate machine learning (ML) and deep learning (DL) algorithms using various molecular features. A large dataset of 2588 chemicals and drugs was randomly divided into training (80%) and test (20%) sets, followed by the training of individual base models using diverse machine learning or deep learning based on three different kinds of descriptors and fingerprints. Feature selection approaches were employed to proceed with model optimizations based on the model performance. Hybrid ensemble approaches were further utilized to determine the method with the best performance., Results: The voting ensemble classifier emerged as the optimal model, achieving an excellent prediction accuracy of 80.26%, AUC of 82.84%, and recall of over 93% followed by bagging and stacking ensemble classifiers method. The model was further verified by an external test set, internal 10-fold cross-validation, and rigorous benchmark training, exhibiting much better reliability than the published models., Conclusion: The proposed ensemble model offers a dependable assessment with a good performance for the prediction regarding the risk of chemicals and drugs to induce liver damage., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Khan, Ren, Cao, Ye, Wang, Guo, Yang and Chen.)
- Published
- 2024
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3. Base-Promoted Nucleophilic Phosphorylation of Benzyl Fluorides via C(sp 3 )-F Cleavage.
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Sun BQ, Yang J, Fan L, Xu Q, Wang S, Zhong H, and Xiang HY
- Abstract
Herein, a transition-metal-free phosphorylation of benzyl fluorides with P(O)-H compounds is disclosed. In the presence of
t BuOK, various benzyl fluorides react with P(O)-H compounds to produce the corresponding benzyl phosphine oxides, phosphinates, and phosphonates in good to high yields. This base-promoted phosphorylation reaction offers a facile and general strategy for the construction of a C(sp3 )-P bond.- Published
- 2024
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4. Visible Light-Induced, Nickel-Catalyzed Late-Stage 4-Alkylation of Hantzsch Esters with Alkyl Bromide.
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Liu YL, He XC, Gao J, Li KR, Chen K, Xiang HY, and Yang H
- Abstract
Herein, visible light-induced, nickel-catalyzed direct functionalization of the Hantzsch esters (HEs) with readily accessible alkyl bromides has been successfully achieved by taking advantage of HE as the reductant and substrate through an aromatization-dearomatization process. In this strategy, the single electron reduction of alkyl bromides by reactive Ni(I) species is essential for the success of this late-stage transformation. A wide range of 4-alkyl-1,4-dihydropyridines were rapidly assembled in moderate to good yields under mild conditions, rendering this photoinduced approach attractive for synthetic and medicinal chemistry.
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- 2024
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5. Genetically modified pigs with CD163 point mutation are resistant to HP-PRRSV infection.
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Liu Y, Yang L, Xiang HY, Niu M, Deng JC, Li XY, Hao WJ, Ou-Yang HS, Liu TY, Tang XC, Pang DX, and Yuan HM
- Subjects
- Animals, Swine, Animals, Genetically Modified genetics, Cell Line, Porcine Reproductive and Respiratory Syndrome genetics, Porcine Reproductive and Respiratory Syndrome virology, Porcine respiratory and reproductive syndrome virus physiology, Porcine respiratory and reproductive syndrome virus genetics, Antigens, Differentiation, Myelomonocytic genetics, Antigens, Differentiation, Myelomonocytic metabolism, Antigens, CD genetics, Antigens, CD metabolism, Receptors, Cell Surface genetics, Receptors, Cell Surface metabolism, Point Mutation
- Abstract
Porcine reproductive and respiratory syndrome (PRRS) is a globally prevalent contagious disease caused by the positive-strand RNA PRRS virus (PRRSV), resulting in substantial economic losses in the swine industry. Modifying the CD163 SRCR5 domain, either through deletion or substitution, can eff1ectively confer resistance to PRRSV infection in pigs. However, large fragment modifications in pigs inevitably raise concerns about potential adverse effects on growth performance. Reducing the impact of genetic modifications on normal physiological functions is a promising direction for developing PRRSV-resistant pigs. In the current study, we identified a specific functional amino acid in CD163 that influences PRRSV proliferation. Viral infection experiments conducted on Marc145 and PK-15
CD163 cells illustrated that the mE535G or corresponding pE529G mutations markedly inhibited highly pathogenic PRRSV (HP-PRRSV) proliferation by preventing viral binding and entry. Furthermore, individual viral challenge tests revealed that pigs with the E529G mutation had viral loads two orders of magnitude lower than wild-type (WT) pigs, confirming effective resistance to HP-PRRSV. Examination of the physiological indicators and scavenger function of CD163 verified no significant differences between the WT and E529G pigs. These findings suggest that E529G pigs can be used for breeding PRRSV-resistant pigs, providing novel insights into controlling future PRRSV outbreaks.- Published
- 2024
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6. Exploring the role of Prx II in mitigating endoplasmic reticulum stress and mitochondrial dysfunction in neurodegeneration.
- Author
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Jin MH, Feng L, Xiang HY, Sun HN, Han YH, and Kwon T
- Subjects
- Humans, Peroxiredoxins genetics, Reactive Oxygen Species metabolism, Oxidative Stress, Apoptosis, Endoplasmic Reticulum Stress, MicroRNAs metabolism, Neurodegenerative Diseases, Mitochondrial Diseases
- Abstract
Background: Neurodegenerative diseases are increasingly recognized for their association with oxidative stress, which leads to progressive dysfunction and loss of neurons, manifesting in cognitive and motor impairments. This study aimed to elucidate the neuroprotective role of peroxiredoxin II (Prx II) in counteracting oxidative stress-induced mitochondrial damage, a key pathological feature of neurodegeneration., Methods: We investigated the impact of Prx II deficiency on endoplasmic reticulum stress and mitochondrial dysfunction using HT22 cell models with knocked down and overexpressed Prx II. We observed alcohol-treated HT22 cells using transmission electron microscopy and monitored changes in the length of mitochondria-associated endoplasmic reticulum membranes and their contact with endoplasmic reticulum mitochondria contact sites (EMCSs). Additionally, RNA sequencing and bioinformatic analysis were conducted to identify the role of Prx II in regulating mitochondrial transport and the formation of EMCSs., Results: Our results indicated that Prx II preserves mitochondrial integrity by facilitating the formation of EMCSs, which are essential for maintaining mitochondrial Ca
2+ homeostasis and preventing mitochondria-dependent apoptosis. Further, we identified a novel regulatory axis involving Prx II, the transcription factor ATF3, and miR-181b-5p, which collectively modulate the expression of Armcx3, a protein implicated in mitochondrial transport. Our findings underscore the significance of Prx II in protecting neuronal cells from alcohol-induced oxidative damage and suggest that modulating the Prx II-ATF3-miR-181b-5p pathway may offer a promising therapeutic strategy against neurodegenerative diseases., Conclusions: This study not only expands our understanding of the cytoprotective mechanisms of Prx II but also offers necessary data for developing targeted interventions to bolster mitochondrial resilience in neurodegenerative conditions., (© 2024. The Author(s).)- Published
- 2024
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7. Realization of Large Low-Stress Elastocaloric Effect in TiZrNbAl Alloy.
- Author
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Lv BH, Xiang HY, Gao S, Guo YX, Yang JH, Zou NF, Zhao X, Li Z, Yang B, Jia N, Yan HL, and Zuo L
- Abstract
Seeking novel high-performance elastocaloric materials with low critical stress plays a crucial role in advancing the development of elastocaloric refrigeration technology. Here, as a first attempt, the elastocaloric effect of TiZrNbAl shape memory alloy at both room temperature and finite temperatures ranging from 245 K to 405 K, is studied systematically. Composition optimization shows that Ti-19Zr-14Nb-1Al (at.%), possessing excellent room-temperature superelasticity with a critical stress of around 100 MPa and a small stress hysteresis of around 70 MPa and outstanding fracture resistance with a compressive strain of 20% and stress of 1.7 GPa, demonstrates a substantial advantage as an elastocaloric refrigerant. At room temperature, a large adiabatic temperature change (ΔTad) of -6.7 K is detected, which is comparable to the highest value reported in the Ti-based alloys. A high elastocaloric cyclic stability, with almost no degradation of ΔTad after 4000 cycles, is observed. Furthermore, the sizeable elastocaloric effect can be steadily expanded from 255 K to 395 K with a temperature window of as large as 140 K. A maximum ΔTad of -7.9 K appears at 355 K. The present work demonstrates a promising potential of TiZrNbAl as a low critical stress and low hysteresis elastocaloric refrigerant.
- Published
- 2024
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8. Identification and diagnostic potential of serum microRNAs as biomarkers for early detection of Alzheimer's disease.
- Author
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Han YH, Xiang HY, Lee DH, Feng L, Sun HN, Jin MH, and Kwon T
- Subjects
- Humans, Biomarkers, Oligonucleotide Array Sequence Analysis, Early Diagnosis, MicroRNAs metabolism, Alzheimer Disease diagnosis, Alzheimer Disease genetics
- Abstract
This study aimed to investigate the differential expression of serum microRNAs in cognitive normal subjects (NC), patients with mild cognitive impairment (MCI), and patients with Alzheimer's disease (AD), with the objective of identifying potential diagnostic biomarkers. A total of 320 clinical samples, including 32 MCI patients, 288 AD patients, and 288 healthy controls, were collected following international standards. The expression of microRNAs in serum was analyzed using the Agilent human microRNA oligonucleotide microarray, and bioinformatics methods were employed to predict target genes and their involvement in AD-related pathways. Among the 122 microRNAs screened, five microRNAs (hsa-miR-208a-5p, hsa-miR-125b-1-3p, hsa-miR-3194-3p, hsa-miR-4652-5p, and hsa-miR-4419a) exhibited differential expression and met quality control standards. Bioinformatics analysis revealed that the target genes of these microRNAs were involved in multiple AD-related pathways, which changed with disease progression. These findings demonstrate significant differences in serum microRNA expression between NC, MCI, and AD patients. Three microRNAs were identified as potential candidates for the development of diagnostic models for MCI and AD. The results highlight the crucial role of microRNAs in the pathogenesis of AD and provide a foundation for the development of novel therapeutic strategies and personalized treatment approaches for AD. This study contributes to the understanding of AD at the molecular level and offers potential avenues for early diagnosis and intervention in AD patients.
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- 2023
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9. A foot structure study of new arch flexibility grading system based on three-dimensional arch volume.
- Author
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Liu J, Deng M, Wang W, Liu XD, Tao L, Xiang HY, and Xiong Y
- Subjects
- Adult, Humans, Male, Biomechanical Phenomena, Foot, Foot Injuries
- Abstract
Purpose: Different arch structures may cause different foot function injuries. In the past, the arch structure and flexibility of the foot were often defined by the height of the arch, and there was no three-dimensional (3D) structure classification method. In order to form a more complete 3D description, we propose a new classification system of arch volume flexibility (AVF), and then use this new classification system to investigate the relationship between the AVF and arch index (AI), and the arch height flexibility (AHF) and AI, respectively., Methods: It is proposed to recruit 180 young male adults for the test. We obtained arch volume and AI through 3D scanning and obtained the navicular height through manual measurement. Based on these data, we calculated the AHF and the AVF. Using the quintile method, these arches are divided into very stiff, stiff, neutral, flexible, and very flexible. According to AI value, all arches were divided into cavus, rectus, and planus. The distribution of AVF was compared using χ
2 goodness of fit test. The spearman correlation test was used to compare the AHF and AVF. A p < 0.05 indicates that the difference is statistically significant., Results: All participants' plantar data was obtained through 3D scanning, but only 159 of them were complete, so only 318 feet had valid data. The left AHF is (21.23 ± 12.91) mm/kN, and the right AHF is (21.71 ± 12.69) mm/kN. The AVF of the left foot arch is (207.35 ± 118.28) mm3 /kg, while the right one is (203.00 ± 117.92) mm3 /kg, and the total AVF of the arch was (205.17 ± 117.94) mm3 /kg. There was no statistical difference in the AVF between the left and right feet for the same participant (n = 159, p = 0.654). In cavus, the percentage of arch with AVF is 21.4% (very stiff), 21.4% (stiff), 14.3% (neutral), 7.1% (flexible), and 35.7% (very flexible). In rectus, the percentage of arch with AVF is 23.9% (very stiff), 19.6% (stiff), 14.7% (neutral), 24.5% (flexible), and 17.2% (very flexible). In planus, the percentage of arch with AVF is 14.9% (very stiff), 20.6% (stiff), 27.0% (neutral), 16.3% (flexible), and 21.3% (very flexible). Moreover, the correlation between AHF and AVF is not significant (p = 0.060)., Conclusion: In cavus, rectus, and planus, different AVF accounts different percentage, but the difference is not statistically significant. AVF is evenly distributed in the arches of the feet at different heights. We further found the relationship between AHF and AVF is not significant. As a 3D index, AVF may be able to describe the flexibility of the arch more comprehensively than AHF., (Copyright © 2023 Chinese Medical Association. Production and hosting by Elsevier B.V. All rights reserved.)- Published
- 2023
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10. Clinical value of chemiluminescence method for detection of antinuclear antibody profiles.
- Author
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Xiang HY, Xiang XY, Ten TB, Ding X, Liu YW, and Luo CH
- Abstract
Background: Antinuclear antibodies (ANAs) are crucial in diagnosing autoimmune diseases, mainly systemic lupus erythematosus (SLE). This study aimed to compare the performance of chemiluminescence assay (CLIA) and line immunoassay (LIA) in detecting ANAs in patients with autoimmune diseases, evaluate their diagnostic accuracy for SLE, and develop a novel diagnostic model using CLIA-detected antibodies for SLE. Specimens from patients with autoimmune diseases and physical examination specimens were collected to parallel detect specific antibodies. Individual antibodies' diagnostic performance and a model combining multiple antibodies were assessed. The findings provide valuable insights into improving the diagnosis of SLE through innovative approaches., Aim: To compare the performance of CLIA and LIA in detecting ANAs in patients with autoimmune diseases, assess their accuracy for SLE, and develop a novel diagnostic model using CLIA-detected antibodies for SLE., Methods: Specimens have been obtained from 270 patients with clinically diagnosed autoimmune disorders, as well as 130 physical examination specimens. After that, parallel detection of anti-double-stranded DNA (dsDNA) antibody, anti-histone (Histone) antibody, anti-nucleosome (Nuc) antibody, anti-Smith (Sm) antibody, anti-ribosomal P protein (Rib-P) antibody, anti-sicca syndrome A (Ro60) antibody, anti-sicca syndrome A (Ro52) antibody, anti-sicca syndrome (SSB) antibody, anti-centromere protein B (Cenp-B) antibody, anti-DNA topoisomerase 1 (Scl-70) antibody, anti-histidyl tRNA synthetase (Jo-1) antibody, and anti-mitochondrial M2 (AMA-M2) antibody was performed using CLIA and LIA. The detection rates, compliance rates, and diagnostic performance for SLE were compared between the two methodologies, followed by developing a novel diagnostic model for SLE., Results: CLIA and LIA exhibited essentially comparable detection rates for anti-dsDNA antibody, anti-Histone antibody, anti-Nuc antibody, anti-Sm antibody, anti-Rib-P antibody, anti-Ro60 antibody, anti-Ro52 antibody, anti-SSB antibody, anti-Cenp-B antibody, anti-DNAScl-70 antibody, anti-Jo-1 antibody and anti-AMA-M2 antibody ( P > 0.05). The two methods displayed identical results for the detection of anti-dsDNA antibody, anti-Histone antibody, anti-Nuc antibody, anti-Sm antibody, anti-Ro60 antibody, anti-Ro52 antibody, anti-SSB antibody, anti-Cenp-B antibody, anti-Scl-70 antibody, and anti-AMA-M2 antibody (Kappa > 0.7, P < 0.05), but showed a moderate agreement for the detection of anti-Rib-P antibody and anti-Jo-1 antibody (Kappa = 0.671 and 0.665; P < 0.05). In addition, the diagnostic performance of these antibodies detected by both methods was similar for SLE. The diagnostic model's area under the curve values, sensitivity, and specificity, including an anti-dsDNA antibody and an anti-Ro60 antibody detected by CLIA, were 0.997, 0.962, and 0.978, respectively. These values were higher than the diagnostic performance of individual antibodies., Conclusion: CLIA and LIA demonstrated excellent overall consistency in detecting ANA profiles. A diagnostic model based on CLIA-detected antibodies can successfully contribute to developing a novel technique for detecting SLE., Competing Interests: Conflict-of-interest statement: All authors declare that there are no conflicts of interest., (©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.)
- Published
- 2023
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11. Photocatalyzed Defluorinative Dichloromethylation of α-CF 3 Alkenes Using CHCl 3 as the Radical Source.
- Author
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Wu MC, Chen YX, Li MZ, Xiao JA, Ye ZP, Guan JP, Xiang HY, Chen K, and Yang H
- Abstract
A visible-light-induced defluorinative dichloromethylation of α-CF
3 alkenes was developed with cheap and readily accessible chloroform simultaneously as a dichloromethylation reagent and reaction medium, leading to the facile preparation of new polyhalogenated scaffolds. Notably, the change from CHCl3 to CDCl3 offers a straightforward pathway for accessing the deuterated analogues with excellent degrees of D incorporation. Mechanistic studies suggested the reaction underwent a radical addition of the dichloromethyl radical with alkenes, followed by sequential single-electron transfer and defluorination. This protocol features mild conditions, easy operation, facile scalability, and high efficiency, allowing convenient access to dichloronated gem -difluoroalkenes.- Published
- 2023
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12. Difference between type 2 gastroesophageal varices and isolated fundic varices in clinical profiles and portosystemic collaterals.
- Author
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Song YH, Xiang HY, Si KK, Wang ZH, Zhang Y, Liu C, Xu KS, and Li X
- Abstract
Background: There is significant heterogeneity between gastroesophageal varices (GOV2) and isolated gastric varices (IGV1). The data on the difference between GOV2 and IGV1 are limited., Aim: To determine the etiology, clinical profiles, endoscopic findings, imaging signs, portosystemic collaterals in patients with GOV2 and IGV1., Methods: Medical records of 252 patients with gastric fundal varices were retrospectively collected, and computed tomography images were analyzed., Results: Significant differences in routine blood examination, Child-Pugh classification and MELD scores were found between GOV2 and IGV1. The incidence of peptic ulcers in patients with IGV1 (26.55%) was higher than that of GOV2 (11.01%), while portal hypertensive gastropathy was more commonly found in patients with GOV2 (22.02%) than in those with IGV1 (3.54%). Typical radiological signs of cirrhotic liver were more commonly observed in patients with GOV2 than in those with IGV1. In patients with GOV2, the main afferent vessels were via the left gastric vein (LGV) (97.94%) and short gastric vein (SGV) (39.18%). In patients with IGV1, the main afferent vessels were via the LGV (75.61%), SGV (63.41%) and posterior gastric vein (PGV) (43.90%). In IGV1 patients with pancreatic diseases, spleno-gastromental-superior mesenteric shunt (48.15%) was a major collateral vessel. In patients with fundic varices, the sizes of gastric/esophageal varices were positively correlated with afferent vessels (LGVs and PGVs) and efferent vessels (gastrorenal shunts). The size of the esophageal varices was negatively correlated with gastrorenal shunts in GOV2 patients., Conclusion: Significant heterogeneity in the etiology and vascular changes between GOV2 and IGV1 is useful in making therapeutic decisions., Competing Interests: Conflict-of-interest statement: All authors have nothing to disclose, (©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.)
- Published
- 2022
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13. Photoinduced Construction of a Benzothienopyridine- S,S -dioxide Framework Enabled by Polychloropyridyl Multifunctional Motifs.
- Author
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Wang ZJ, Zheng Y, Tang K, Guan JP, Ye ZP, He JT, Xiao JA, Chen K, Xiang HY, and Yang H
- Abstract
Reported herein is a visible-light-induced, catalyst-free intramolecular cyclization of 4-phenylsulfonyl-2,3,5,6-tetrachloropyridine, leading to rapid assembly of a series of unprecedented benzo[4,5]thieno[3,2- c ]pyridine 5,5-dioxide scaffolds under mild conditions. The rational introduction of a perchloropyridin-4-yl module significantly facilitated this photoinduced process and offers a versatile platform for broad structural variation. Mechanistic studies revealed that a newly identified charge-transfer complex with carbonate is crucial to this photoinduced process.
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- 2022
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14. Phosphine-Mediated Morita-Baylis-Hillman-Type/Wittig Cascade: Access to E -Configured 3-Styryl- and 3-(Benzopyrrole/furan-2-yl) Quinolinones.
- Author
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Zheng Y, Wang ZW, Cheng WS, Xie ZZ, He XC, Chen YS, Chen K, Xiang HY, Chen XQ, and Yang H
- Subjects
- Cyclization, Furans, Phosphines, Quinolones
- Abstract
A phosphine-mediated, well-designed Morita-Baylis-Hillman-type/Wittig cascade for the rapid assembly of a quinolinone framework from benzaldehyde derivatives is developed for the first time. By rationally combining I
2 /NIS-mediated cyclization, biologically relevant 3-(benzopyrrole/furan-2-yl) quinolinones were facilely synthesized in a one-pot process by starting from 3-styryl-quinolinones bearing an o -hydroxy/amino group, significantly expanding the chemical space of this privileged skeleton. Further utility of this protocol is illustrated by successfully performing this transformation in a catalytic manner through in situ reduction of phosphine oxide by phenylsilane.- Published
- 2022
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15. Photoredox-Catalyzed Cascade of o- Hydroxyarylenaminones to Access 3-Aminated Chromones.
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Wang ZW, Zheng Y, Qian YE, Guan JP, Lu WD, Yuan CP, Xiao JA, Chen K, Xiang HY, and Yang H
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- Amination, Catalysis, Chromones
- Abstract
Reported herein is a photoredox-catalyzed amination of o- hydroxyarylenaminones with tert -butyl ((perfluoropyridin-4-yl)oxy)carbamate, a versatile amidyl-radical precursor developed in our laboratory. This work establishes a new cascade pathway for the assembly of a range of 3-aminochromones under mild conditions. Downstream transformations of the obtained 3-aminochromones to construct diverse amino pyrimidines greatly broaden the applications of this photocatalyzed protocol.
- Published
- 2022
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16. Visible Light-Promoted Radical Relay Cyclization/C-C Bond Formation of N -Allylbromodifluoroacetamides with Quinoxalin-2(1 H )-ones.
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Ye ZP, Liu F, Duan XY, Gao J, Guan JP, Xiao JA, Xiang HY, Chen K, and Yang H
- Subjects
- Cyclization, Lactams, Molecular Structure, Light, Quinoxalines
- Abstract
A visible light-promoted radical relay of N -allylbromodifluoroacetamide with quinoxalin-2(1 H )-ones was developed in which 5- exo - trig cyclization and C-C bond formation were involved. This protocol was performed under mild conditions to facilely offer a variety of hybrid molecules bearing both quinoxalin-2(1 H )-one and 3,3-difluoro-γ-lactam motifs. These prepared novel skeletons would expand the accessible chemical space for structurally complex heterocycles with potential biological activities.
- Published
- 2021
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17. N , N , N ', N '-Tetramethylethylenediamine-Enabled Photoredox-Catalyzed C-H Methylation of N -Heteroarenes.
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Liu F, Ye ZP, Hu YZ, Gao J, Zheng L, Chen K, Xiang HY, Chen XQ, and Yang H
- Subjects
- Catalysis, Methylation, Ethylenediamines, Protons
- Abstract
Aiming at the valuable methylation process, readily available and inexpensive N , N , N' , N' -tetramethylethylenediamine (TMEDA) was first identified as a new methyl source in photoredox-catalyzed transformation in this work. By virtue of this simple methylating reagent, a facile and practical protocol for the direct C-H methylation of N -heteroarenes was developed, featuring mild reaction conditions, broad substrate scope, and scalability. Mechanistic studies disclosed that a sequential photoredox, base-assisted proton shift, fragmentation, and tautomerization process was essentially involved.
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- 2021
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18. Visible-Light-Driven, Photocatalyst-Free Cascade to Access 3-Cyanoalkyl Coumarins from ortho -Hydroxycinnamic Esters.
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Hu YZ, Ye ZP, Xia PJ, Song D, Li XJ, Liu ZL, Liu F, Chen K, Xiang HY, and Yang H
- Abstract
A visible-light-driven, photocatalyst-free route starting from easily accessed ortho -hydroxycinnamic esters and O -perfluoropyridin-4-yl oximes has been successfully developed to rapidly assemble a wide range of 3-cyanoalkyl coumarins. This process does not require addition of external photocatalysts, exhibiting beneficial features including mild reaction conditions, synthetic simplicity, and excellent substrate compatibility. Extensive mechanistic investigations revealed that the in situ generated phenolate anions served as photosensitizers to drive this photoinduced transformation.
- Published
- 2021
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19. [A retrospective evaluation of clinicalopathologic characteristics and prognostic factors for synchronous bilateral breast cancer in a single center].
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Xin L, Xiang HY, and Liu YH
- Subjects
- Disease-Free Survival, Humans, Mastectomy, Neoplasm Staging, Prognosis, Retrospective Studies, Breast Neoplasms pathology
- Abstract
Objective: To investigate the clinicopathologic features of synchronous bilateral breast cancer (SBBC) and prognostic factors. Methods: The clinicopathologic features of patients with SBBC treated in Peking University First Hospital from January 2008 to March 2019 were retrospectively analyzed. Results: Of all 4 111 patients diagnosed with breast cancer, 57(1.4%) cases were diagnosed with SBBC.Forty-three (75.4%) patients were treated with bilateral mastectomy. The median follow-up time was 58 months. The 5-year disease-free survival of SBBC was 80.7% and 5-year overall survival was 84.1%. The N stage and HER2 status of second primary breast cancer were associated with prognosis by univariated analysis ( Z =5.866 and 4.231, both P <0.05). Conclusion: Majority of patients with SBBC were treated with bilateral mastectomy. While therapeutic strategy of SBBC should take both tumor burden and biomarker status of bilateral breast cancer into consideration.
- Published
- 2021
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20. Retrospective analysis of sentinel lymph node biopsy using methylene blue dye for early breast cancer.
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Yang S, Xiang HY, Xin L, Zhang H, Zhang S, Cheng YJ, Liu Q, Xu L, Li T, Duan XN, Ye JM, and Liu YH
- Subjects
- China, Humans, Lymph Nodes, Methylene Blue, Retrospective Studies, Breast Neoplasms surgery, Sentinel Lymph Node Biopsy
- Abstract
Background: Methylene blue is the most commonly used tracer for sentinel lymph node (SLN) biopsy (SLNB) in China. This study aimed to investigate the feasibility of clinical application of SLNB using methylene blue dye (MBD) for early breast cancer and the prognosis of patients with different SLN and non-SLN statuses., Methods: We retrospectively analyzed the clinicopathological data of patients with early breast cancer treated at the Peking University First Hospital between 2013 and 2018. We calculated the SLN identification rate (IR) in SLNB with MBD and the false-negative rate (FNR), and analyzed the prognosis of patients with different SLN and non-SLN statuses using Kaplan-Meier curves., Results: Between January 2013 and December 2018, 1603 patients with early breast cancer underwent SLNB with MBD. The SLN IR was 95.8% (1536/1603). Two SLNs (median) were detected per patient. There were significant differences in FNR between patients with SLN micrometastasis and macrometastasis (19.0% vs. 4.5%, χ2 = 12.771, P < 0.001). Chi-square test showed that there were significant differences in SLN successful detection rates among patients with different vascular tumor embolism status (96.3% vs. 90.8%, χ2 = 9.013, P = 0.003) and tumor (T) stages (96.6% vs. 94.1%, χ2 = 5.189, P = 0.023). Multivariate analysis showed that vascular tumor embolism was the only independent factor for SLN successful detection (odds ratio: 0.440, 95% confidence interval: 0.224-0.862, P = 0.017). Survival analysis showed a significant difference in disease-free survival (DFS) between patients with non-SLN metastasis and patients without non-SLN metastasis (P = 0.006)., Conclusion: Our single-center data show that, as a commonly used tracer in SLNB in China, MBD has an acceptable SLN IR and a low FNR in frozen sections. This finding is consistent with reports of dual tracer-guided SLNB. Positive SLNs with non-SLN metastasis are associated with DFS., (Copyright © 2021 The Chinese Medical Association, produced by Wolters Kluwer, Inc. under the CC-BY-NC-ND license.)
- Published
- 2021
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21. Photocatalytic Hydroacylation of Alkenes by Directly Using Acyl Oximes.
- Author
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Zheng L, Xia PJ, Zhao QL, Qian YE, Jiang WN, Xiang HY, and Yang H
- Abstract
Acyl oximes are directly used as the acyl radical precursors in the hydroacylation reactions for the first time. In this work, acyl radicals can be effectively generated via β -scission of a phosphoranyl radical under photocatalytic conditions. As a result, the hydroacylation of alkenes triggered by the resulting acyl radicals leads to facile syntheses of a range of valuable ketones.
- Published
- 2020
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22. Repeated measures of prenatal thallium exposure and placental inflammatory cytokine mRNA expression: The Ma'anshan birth cohort (MABC) study.
- Author
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Zhu YD, Liang CM, Hu YB, Li ZJ, Wang SF, Xiang HY, Huang K, Yan SQ, Zhu P, Liu P, and Tao FB
- Subjects
- Adult, China, Cohort Studies, Environmental Pollutants toxicity, Female, Humans, Male, Pregnancy, Pregnancy Trimester, First, Pregnancy Trimester, Third, Pregnancy Trimesters, Prenatal Exposure Delayed Effects epidemiology, Prospective Studies, Research Design, Thallium toxicity, Cytokines metabolism, Environmental Pollutants metabolism, Maternal Exposure statistics & numerical data, Placenta metabolism, RNA, Messenger metabolism, Thallium metabolism
- Abstract
Thallium (Tl), a ubiquitous environmental toxicant, can cross the placental barrier during pregnancy. However, the effects of prenatal Tl exposure on placental function are currently unclear. Based on the Ma'anshan Birth Cohort study, we examined whether long-term prenatal Tl exposure was associated with placental inflammation. Tl concentrations were quantified in serum samples (n = 7050) from 2515 pregnancy during each trimester, placental inflammatory cytokine mRNA expression was assessed in 2519 placenta tissues. Geometric mean values of serum Tl concentrations were 63.57, 63.63 and 48.71 ng/L for the first, second and third trimesters, respectively. After adjustment for potential confounders, serum Tl concentration was positively associated with CD68 (β: 0.30; 95% CI: 0.05, 0.56) in the first trimester and TNF-α (β: 0.12; 95% CI: 0.01, 0.23), IL-6 (β: 0.15; 95% CI: 0.05, 0.25) and CD68 (β: 0.25; 95% CI: 0.10, 0.39) in the third trimester, however was negatively associated with IL-4 (β: -0.21; 95% CI: -0.41, -0.01) and CD206 (β: -0.23; 95% CI: -0.45, -0.02) in the first trimester. Repeated measures analysis showed that TNF-α, IL-6 and CD68 increased by 0.11 (95% CI: 0.01, 0.21), 0.12 (0.15, 95% CI: 0.05, 0.25), 0.22 (95% CI: 0.10, 0.39), respectively, with each 1ln-transformed Tl increase in total samples. Gender-specific analyses revealed that these associations were largely driven by male offspring. In addition, immunohistochemistry revealed that nuclear NF-κB p65 expression increased in placenta tissue. The results of this prospective cohort study provide longitudinal evidence that prenatal Tl exposure induces a placental inflammatory response in the Chinese population., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2019 Elsevier Ltd. All rights reserved.)
- Published
- 2020
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23. Visible-Light-Induced, Catalyst-Free Radical Cross-Coupling Cyclization of N -Allylbromodifluoroacetamides with Disulfides or Diselenides.
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Ye ZP, Xia PJ, Liu F, Hu YZ, Song D, Xiao JA, Huang P, Xiang HY, Chen XQ, and Yang H
- Abstract
A visible-light-induced, catalyst-free radical cross-coupling cyclization of diselenides or disulfides with N -allylbromodifluoroacetamide has been developed. This developed protocol exhibits good functional group tolerance and affords a variety of 4-thio- and 4-seleno-substituted 3,3-difluoro-γ-lactams in moderate to good yields. Based on control experiments, a plausible radical-radical cross-coupling pathway is proposed.
- Published
- 2020
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24. Prenatal serum thallium exposure and 36-month-old children's attention-deficit/hyperactivity disorder symptoms: Ma'anshan birth cohort study.
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Tong J, Liang CM, Huang K, Xiang HY, Qi J, Feng LL, Lai YP, Shao SS, Wu XY, and Tao FB
- Subjects
- Attention Deficit Disorder with Hyperactivity diagnosis, Child, Preschool, Cohort Studies, Female, Fetal Blood, Humans, Infant, Newborn, Male, Mothers, Pregnancy, Pregnancy Trimester, Second blood, Pregnancy Trimester, Third blood, Prenatal Exposure Delayed Effects diagnosis, Sex Factors, Thallium toxicity, Attention Deficit Disorder with Hyperactivity blood, Prenatal Exposure Delayed Effects blood, Thallium blood
- Abstract
Thallium (Tl) is a highly toxic heavy metal that has been suggested to be responsible for oxidative stress and mitochondrial dysfunction. However, few studies have focused on the relationship of prenatal Tl exposure with children's neurobehavioural development. The purpose of our study was to investigate the association between prenatal Tl exposure and attention-deficit/hyperactivity disorder (ADHD) symptoms in 36-month-old children. We used data from 2851 mother-newborn pairs from the Ma'anshan Birth Cohort Study (MABC); serum Tl concentration was assessed in the first, second and third trimesters of pregnancy as well as in the umbilical cord blood. We assessed ADHD symptoms in the children using the Chinese version of the Conners abbreviated symptom questionnaire (C-ASQ). The adjusted odds ratio (OR) for the risk of ADHD symptoms was 2.00 [95% confidence interval (CI): 1.20, 3.32] and 2.08 (95% CI: 1.26, 3.43) for the third (60.25-75.21 ng/L) and fourth quartiles of serum Tl (>75.21 ng/L), respectively, in the second trimester of pregnancy, in comparison with the first quartile of serum Tl (<50.86 ng/L). The risk of ADHD symptoms was elevated among boys exposed to the fourth quartile of serum Tl in the second trimester of pregnancy (adjusted OR 2.08, 95% CI: 1.13, 3.83). Our results demonstrated that high levels of Tl exposure in the second trimester of pregnancy were related to a higher risk of ADHD symptoms in 36-month-old children, and the association of higher serum Tl exposure in the second trimester with ADHD symptoms was only found in boys., (Copyright © 2019 Elsevier Ltd. All rights reserved.)
- Published
- 2020
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25. Construction of arming Yarrowia lipolytica surface-displaying soybean seed coat peroxidase for use as whole-cell biocatalyst.
- Author
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Wang JM, Wang CM, Men X, Yue TQ, Madzak C, Xiang XH, Xiang HY, and Zhang HB
- Subjects
- Biocatalysis, Cloning, Molecular, Enzyme Stability, Gene Expression, Peroxidases chemistry, Peroxidases metabolism, Plasmids genetics, Plasmids metabolism, Soybean Proteins chemistry, Soybean Proteins metabolism, Yarrowia metabolism, Peroxidases genetics, Soybean Proteins genetics, Yarrowia genetics
- Abstract
Whole-cell biocatalysts could be used in wide-ranging applications. In this study, a new kind of whole-cell biocatalyst was successfully constructed by genetically immobilizing soybean seed coat peroxidase (SBP) on the cell surface of Yarrowia lipolytica Po1h, using a new integrative surface display expression vector (pMIZY05). The coding sequence of SBP was optimized and chemically synthesized, then inserted into pMIZY05 to generate expression plasmid pMIZY05-oEp. A DNA fragment corresponding to SBP and selection marker expression cassettes, without bacterial sequences, was released from pMIZY05-oEp by enzyme digestion and used to transform host yeast cells. A transformant (CM11) with a high recombinant SBP activity of 1571.9 U/mL was obtained, and recombinant SBP was proved to be successfully anchored on cell surface by testing the activities of different cellular fractions. After optimization of culture conditions, the recombinant SBP activity of CM11 was increased to 4187.8 U/mL. Afterwards, biochemical properties of the recombinant SBP were determined: optimum catalytic conditions were 37.5℃ at pH 3.5, and recombinant SBP exhibited high stability during thermal or acidic treatment. Recombinant activity of cell-displayed SBP was re-examined at optimum temperature and pH, which promoted an increase up to 4432.5 U/mL. To our knowledge, this represents the highest activity ever reported for heterologous expression of SBP. This study also provides a useful strategy for heterologous expression of proteins which could be toxic to intracellular content of host cells., (Copyright © 2019. Published by Elsevier Inc.)
- Published
- 2020
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26. O -Perfluoropyridin-4-yl Oximes: Iminyl Radical Precursors for Photo- or Thermal-Induced N-O Cleavage in C(sp 2 )-C(sp 3 ) Bond Formation.
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Xia PJ, Hu YZ, Ye ZP, Li XJ, Xiang HY, and Yang H
- Abstract
O -Perfluoropyridin-4-yl group was first installed onto cycloketone oximes as a new electrophore, which was proven to be efficient iminyl radical precursors under photocatalytic and thermal conditions. A range of O -perfluoropyridin-4-yl oximes were successfully utilized in C(sp
2 )-C(sp3 ) bond formations of quinoxalin-2(1 H )-ones and alkenes, providing facile accesses to a range of functionalized alkylnitriles.- Published
- 2020
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27. Clinicopathologic analysis of 722 breast cancer patients who met the inclusion criteria of the TAILORx trial.
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Xiang HY, Liu YH, Zhang H, Zhang S, Xin L, Xu L, Ye JM, Li T, Duan XN, and Liu Q
- Subjects
- Adult, Aged, Breast Neoplasms drug therapy, Breast Neoplasms mortality, Chemotherapy, Adjuvant, Female, Humans, Middle Aged, Prognosis, Receptor, ErbB-2 analysis, Receptors, Estrogen analysis, Retrospective Studies, Young Adult, Breast Neoplasms pathology
- Abstract
Background: The results of the Trial Assigning IndividuaLized Options for Treatment (TAILORx) suggested that approximately 70% of T1-2N0M0, hormone receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer patients can avoid chemotherapy and receive only adjuvant endocrine therapy. We conducted a retrospective analysis of the clinicopathologic features and prognostic factors of patients with breast cancer who met the inclusion criteria of the TAILORx trial., Methods: According to the enrollment criteria of the TAILORx trial, a retrospective analysis was performed on patients with breast cancer who were treated from January 2008 to December 2015 at Peking University First Hospital. The clinicopathologic characteristics of all patients were analyzed, and prognoses were calculated using the Kaplan-Meier method and a Cox proportionate hazards model., Results: A total of 2430 patients with early stage breast cancer who were admitted at our hospital had complete clinicopathologic data and follow-up information. Of these patients, 722 met the inclusion criteria and were enrolled in the present study, accounting for 29.7% of all patients. Among them, 417 (57.8%) patients received only adjuvant endocrine therapy (the non-chemo group), and 305 (42.2%) patients received adjuvant chemotherapy followed by adjuvant endocrine therapy (the chemo group). No statistically significant difference was observed in overall survival (OS) between the two groups (non-chemo vs. chemo: 5-year OS: 97.9% vs. 97.9%, χ = 1.00, P = 0.995; hazard ratio [HR] = 1.00, 95% confidence interval [CI]: 0.46-2.21). A significant difference was observed in disease-free survival (DFS) between the two groups (non-chemo vs. chemo: 5-year DFS: 97.9% vs. 94.7%, χ = 8.65, P = 0.003; HR = 3.05, 95% CI: 1.40-6.67). The choice of adjuvant therapy was associated with clinicopathologic factors, such as the age at diagnosis, T stage, histologic grade, the Ki67 index, the presence of intravascular tumor thrombus (P < 0.001), pathologic type, and menstrual status (P = 0.014)., Conclusions: In the absence of internationally recognized multigene testing methods, for patients with early hormone receptor-positive, HER2-negative breast cancer, clinicians can develop a treatment plan based on clinicopathologic features only, which can effectively screen some patients who do not need adjuvant chemotherapy. However, nearly half of patients still receive adjuvant chemotherapy, and whether these patients can be exempted from chemotherapy warrants further exploration.
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- 2019
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28. Prenatal phthalate exposure in relation to gestational age and preterm birth in a prospective cohort study.
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Gao H, Wang YF, Huang K, Han Y, Zhu YD, Zhang QF, Xiang HY, Qi J, Feng LL, Zhu P, Hao JH, Tao XG, and Tao FB
- Subjects
- Female, Humans, Infant, Newborn, Pregnancy, Pregnancy Trimesters, Prospective Studies, Gestational Age, Maternal Exposure statistics & numerical data, Phthalic Acids, Premature Birth epidemiology
- Abstract
This study enrolled 3266 pregnant women, to explore the relationship of prenatal phthalate exposure with the risk of preterm birth and gestational age. All participants filled questionnaires and provided with up to three urine samples during three trimesters. Seven phthalate metabolites in urines were measured. The incidences of very preterm, late preterm, early-term, late-term and postterm births were 0.58%, 3.52%, 24.22%, 10.53%, and 0.34%, respectively. Non-linear relationships were shown between phthalate metabolites and gestational age. Except for monomethyl phthalate (OR = 1.65, 95%CI = 1.17-2.34), the average concentrations of phthalate metabolites were associated with a slightly and insignificantly increased risk of overall preterm birth (<37
+0 gestational weeks). Through a restricted cubic spline regression, phthalate metabolites were found to be related to the risk of overall preterm birth in a linear manner (p-value >0.05) or a non-linear manner (p-value <0.05). All curves indicated the overall preterm birth risk rose with the increase of phthalate metabolite concentrations. Finally, compared with full-term birth (39+0 to 40+6 gestational weeks), phthalate metabolites were associated with the elevated risks of very preterm, late preterm and postterm births, although some relationships were not statistically significant. In conclusion, these findings suggested non-linear associations between phthalate metabolites and gestational age. Exposure to some phthalate metabolites was associated with increased risks of overall preterm birth and postterm birth., (Copyright © 2019 Elsevier Inc. All rights reserved.)- Published
- 2019
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29. Visible-Light-Driven, Photoredox-Catalyzed Cascade of ortho-Hydroxycinnamic Esters To Access 3-Fluoroalkylated Coumarins.
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Song D, Wang CM, Ye ZP, Xia PJ, Deng ZX, Xiao JA, Xiang HY, and Yang H
- Abstract
A general and straightforward protocol for di-/perfluoroalkylation of ortho-hydroxycinnamic esters via a photoredox-catalyzed cascade was developed to access a variety of 3-fluoroalkylated coumarins. This method was characterized by all-in-one synthetic design, simplified operation, mild reaction conditions, and broad substrate scope. Moreover, a sequential one-pot procedure starting from commercially available salicylaldehyde was also successfully realized to synthesize 3-fluoroalkylated coumarins.
- Published
- 2019
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30. Trace element profiles in pregnant women's sera and umbilical cord sera and influencing factors: Repeated measurements.
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Liang CM, Wu XY, Huang K, Yan SQ, Li ZJ, Xia X, Pan WJ, Sheng J, Tao YR, Xiang HY, Hao JH, Wang QN, Tao FB, and Tong SL
- Subjects
- Adult, Asian People, Female, Humans, Pregnancy, Seasons, Time Factors, Umbilical Cord blood supply, Young Adult, Fetal Blood chemistry, Metals, Heavy blood, Trace Elements blood
- Abstract
In utero exposure to toxic heavy metals and deficient or excessive essential trace elements during pregnancy may have adverse effects on pregnant women and their offsprings, which are of great concern. The objective of the present study was to characterize serum concentrations of multiple trace elements at multiple time points during pregnancy in Chinese women. Three thousand four hundred and sixteen pregnant women in total were included from MABC (Ma'anshan Birth Cohort) study. Fasting sera in the morning and questionnaires were obtained at three separate follow-up visits. Nineteen trace elements from serum samples were analyzed, including aluminum (Al), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), selenium (Se), cadmium (Cd), barium (Ba), thallium (Tl), lead (Pb), calcium (Ca), magnesium (Mg), mercury (Hg) and molybdenum (Mo). The total detection rates for most elements were 100% rather than Ni (99.98%), As (99.97%), Cd (99.6%), Ba (99.9%), Pb (99.8%), Hg (99.8%). The concentration distributions of 19 elements varied vastly. Median concentrations for all trace elements ranged from 38.5 ng/L to 102.9 mg/L. The moderate interclass correlation coefficients (ICCs) were observed for Co, Cu, Se and Hg, ranging from 0.40 to 0.62; the lower ICCs, ranging from 0.13 to 0.32 were for Fe, Zn, Cd, Ba, Tl, Mg and Mo. The intraclass correlation effects were not observed for the remaining elements, such as Al, V, Cr, Mn, Ni, As and Pb. The concentrations of each element between three time points were significantly different; significant differences were also found between any two time points except for Ni, Cd and Mo. Many factors could affect the levels of trace elements, and a very important factor of them was season. Consequently, a single measurement of elements in sera seems not enough to describe exposure levels throughout pregnancy; additionally, season affected exposure levels of trace elements with moderate ICCs showed certain regularity. Future analyses should take sampling seasons into consideration carefully., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2019
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31. Association between maternal and umbilical cord serum cobalt concentration during pregnancy and the risk of preterm birth: The Ma'anshan birth cohort (MABC) study.
- Author
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Li ZJ, Liang CM, Xia X, Huang K, Yan SQ, Tao RW, Pan WJ, Sheng J, Tao YR, Xiang HY, Hao JH, Wang QN, Tong SL, and Tao FB
- Subjects
- Adult, China, Cohort Studies, Female, Humans, Infant, Newborn, Logistic Models, Pregnancy, Premature Birth blood, Risk Factors, Cobalt blood, Fetal Blood chemistry, Pregnancy Trimester, First blood, Pregnancy Trimester, Second blood, Premature Birth etiology
- Abstract
Cobalt is an essential trace element and has been suggested to be involved in oxidative stress and inflammatory responses. However, researches have paid little attention to the association between serum cobalt levels during pregnancy and the risk of preterm birth (PTB, <37 week of gestation). The purpose of this study was to determine the association between maternal and umbilical cord serum cobalt concentrations and the risk of PTB. A total of 2951, 3080, and 2698 serum samples were obtained from pregnant women in the first, the second trimester, and the umbilical cord blood, respectively. The tertile levels of ln-transformed cobalt were defined as low, medium and high levels for cobalt respectively. In our study, the rate of PTB (<37 weeks of gestation) was elevated in subjects with low cobalt levels in the first trimester of pregnancy (adjusted OR 1.61, 95% CI: 1.01, 2.58) and the second trimester of pregnancy (adjusted OR 1.62, 95% CI: 1.03, 2.54). The adjusted OR for PTB was 2.46 (95% CI: 1.34, 4.53) among subjects with low cobalt levels and 2.22 (95% CI: 1.19, 4.15) among subjects with medium cobalt levels in the umbilical cord serum. Our findings demonstrated that the lower levels in maternal and umbilical cord serum cobalt were associated with the increased the risk of PTB., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2019
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32. Organocatalytic Domino Entry to an Octahydroacridine Scaffold Bearing Three Contiguous Stereocenters.
- Author
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Li S, Wang J, Xia PJ, Zhao QL, Wang CM, Xiao JA, Chen XQ, Xiang HY, and Yang H
- Abstract
A facile and enantioselective access to a functionalized octahydroacridine scaffold was developed via an organocatalytic domino sequence between cyclohexenone and 2- N-substituted benzaldehyde. High levels of yields (up to 99%) and enantioselectivities (up to 99:1 er) were readily achieved in this developed organocatalytic transformation, which holds promising applications in the construction of complex multicyclic systems for further pharmacological studies.
- Published
- 2018
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33. The Conserved Proline18 in the Polerovirus P3a Is Important for Brassica Yellows Virus Systemic Infection.
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Zhang XY, Zhao TY, Li YY, Xiang HY, Dong SW, Zhang ZY, Wang Y, Li DW, Yu JL, and Han CG
- Abstract
ORF3a, a newly identified non-AUG-initiated ORF encoded by members of genera Polerovirus and Luteovirus , is required for long-distance movement in plants. However, the mechanism of action of P3a in viral systemic movement is still not clear. In this study, sequencing of a brassica yellows virus (BrYV) mutant defective in systemic infection revealed two-nucleotide variation at positions 3406 and 3467 in the genome. Subsequent nucleotide substitution analysis proved that only the non-synonymous substitution (C→U) at position 3406, resulting in P3a
P18L , abolished the systemic infection of BrYV. Preliminary investigation showed that wild type BrYV was able to load into the petiole of the agroinfiltrated Nicotiana benthamiana leaves, whereas the mutant displayed very low efficiency. Further experiments revealed that the P3a and its mutant P3aP18L localized to the Golgi apparatus and near plasmodesmata, as well as the endoplasmic reticulum. Both P3a and P3aP18L were able to self-interact in vivo , however, the mutant P3aP18L seemed to form more stable dimer than wild type. More interestingly, we confirmed firstly that the ectopic expression of P3a of other poleroviruses and luteoviruses, as well as co-infection with Pea enation mosaic virus 2 (PEMV 2), restored the ability of systemic movement of BrYV P3a defective mutant, indicating that the P3a is functionally conserved in poleroviruses and luteoviruses and is redundant when BrYV co-infects with PEMV 2. These observations provide a novel insight into the conserved function of P3a and its underlying mechanism in the systemic infection.- Published
- 2018
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34. Solvent-Minimized, Chromatography-Free, Diastereoselective Synthesis of Oxazolidine-Dispirooxindoles via oxa-1,3-Dipolar Cycloaddition of 3-Oxindole.
- Author
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Xia PJ, Li J, Qian YL, Zhao QL, Xiang HY, Xiao JA, Chen XQ, and Yang H
- Abstract
An efficient and diastereoselective decarboxylative oxa-1,3-dipolar cycloaddition between 3-oxindoles and diverse amino acids is developed to access novel oxazolidine-dispirooxindole skeletons bearing vicinal quaternary carbon centers. This protocol features operational simplicity, a broad substrate scope, and good to excellent chemical yields and diastereoselectivities. In particular, minimal solvent (1 mL/10 mmol) and chromatography-free purification render this synthetic process more efficient and environmentally benign in the context of green chemistry.
- Published
- 2018
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35. Organocatalytic Asymmetric Allylic Alkylation of Morita-Baylis-Hillman Carbonates with Diethyl 2-Aminomalonate Assisted by In Situ Protection.
- Author
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Zheng Y, Wang J, Xia PJ, Zhao QL, Xiao JA, Xiang HY, Chen XQ, and Yang H
- Abstract
With the aid of in situ protection by N-(2-formylphenyl)-4-methyl-benzenesulfonamide, enantioselective allylic alkylation of Morita-Baylis-Hillman carbonates with diethyl 2-aminomalonate was successfully realized. The corresponding adducts can be obtained in up to 99% yield with up to 98% ee as well as excellent regioselectivity. Besides, the adducts with opposite configurations were readily prepared by utilizing easily available and inexpensive quinine or quinidine as organocatalyst. Facile deprotection of the resulting adduct provides straightforward access to enantiopure α-methylene-γ-lactam.
- Published
- 2017
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36. L-Pyroglutamic Sulphonamide as Hydrogen-Bonding Organocatalyst: Enantioselective Diels-Alder Cyclization to Construct Carbazolespirooxindoles.
- Author
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Ren JW, Wang J, Xiao JA, Li J, Xiang HY, Chen XQ, and Yang H
- Abstract
Hydrogen-bonding organocatalysts L-pyroglutamic sulphonamides were readily synthesized for the first time by fully exploiting the potentials of L-pyroglutamic acid. The newly designed catalyst was successfully applied in catalyzing asymmetric Diels-Alder cyclization of methyleneindolinones with 2-vinyl-1H-indoles to efficiently assemble carbazolespirooxindoles in excellent stereoselectivity (up to 99% ee, >20:1 dr) and yields (up to 99%). Mechanistic studies disclosed that the well-designed hydrogen-bonding modes between L-pyroglutamic sulphonamide and substrates were crucial for stereocontrol in the cyclization.
- Published
- 2017
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37. Photoredox-Catalyzed Reductive Dimerization of Isatins and Isatin-Derived Ketimines: Diastereoselective Construction of 3,3'-Disubstituted Bisoxindoles.
- Author
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Wang CM, Xia PJ, Xiao JA, Li J, Xiang HY, Chen XQ, and Yang H
- Abstract
Reductive dimerization of isatin and its derivatives can be regarded as a step-economical pathway to construct 3,3'-disubstituted bisoxindoles, which was unfortunately accompanied by severe direct reduction as well as low efficiency. A visible-light driven, photoredox-catalytic protocol was developed to readily furnish 3,3'-dihydroxy- (dl-, > 20:1 dr) and 3,3'-diamino-bisoxindoles (meso-, 3.5:1 to 5:1 dr) in moderate to good yields, successfully circumventing the common problem. Two vicinal quaternary carbon centers were effectively assembled under the irradiation of visible light.
- Published
- 2017
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38. Diastereoselective Intramolecular [3 + 2]-Annulation of Donor-Acceptor Cyclopropane with Imine-Assembling Hexahydropyrrolo[3,2-c]quinolinone Scaffolds.
- Author
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Xiao JA, Li J, Xia PJ, Zhou ZF, Deng ZX, Xiang HY, Chen XQ, and Yang H
- Abstract
An intramolecular [3 + 2]-annulation of amide-linked donor-acceptor cyclopropane with in situ-generated imine is described. As a result, diverse hexahydropyrrolo[3,2-c]quinolinones, as the tricyclic core of martinellines, were efficiently assembled in good to excellent yield (up to 93%) with a good diastereomeric ratio (up to 98:2).
- Published
- 2016
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39. MicroRNA involvement in mechanism of endogenous protection induced by fastigial nucleus stimulation based on deep sequencing and bioinformatics.
- Author
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Feng LB, Pang XM, Zhang L, Li JP, Huang LG, Su SY, Zhou X, Li SH, Xiang HY, Chen CY, and Liu JL
- Subjects
- Animals, Brain Ischemia complications, Male, Molecular Sequence Annotation, Rats, Rats, Sprague-Dawley, Reperfusion Injury complications, Reperfusion Injury genetics, Reperfusion Injury physiopathology, Reperfusion Injury therapy, Cerebellar Nuclei, Computational Biology, Deep Brain Stimulation, High-Throughput Nucleotide Sequencing, MicroRNAs genetics, Neuroprotection genetics, Sequence Analysis, RNA
- Abstract
Background: Neurogenic neuroprotection is a promising approach for treating patients with ischemic brain lesions. Fastigial nucleus stimulation (FNS) has been shown to reduce the tissue damage resulting from focal cerebral ischemia in the earlier studies. However, the mechanisms of neuroprotection induced by FNS remain unclear. MicroRNAs (miRNAs) are a newly discovered group of non-coding small RNA molecules that negatively regulate target gene expression and involved in the regulation of pathological process. To date, there is a lack of knowledge on the expression of miRNA in response to FNS. Thus, we study the regulation of miRNAs in the rat ischemic brain by the neuroprotection effect of FNS., Methods: In this study, we used an established focal cerebral ischemia/reperfusion (IR) model in rats. MiRNA expression profile of rat ischemic cortex after 1 h of FNS were investigated using deep sequencing. Microarray was performed to study the expression pattern of miRNAs. Functional annotation on the miRNA was carried out by bioinformatics analysis., Results: Two thousand four hundred ninety three miRNAs were detected and found to be miRNAs or miRNA candidates using deep sequencing technology. We found that the FNS-related miRNAs were differentially expressed according microarray data. Bioinformatics analysis indicated that several differentially expressed miRNAs might be a central node of neuroprotection-associated genetic networks and contribute to neuroprotection induced by FNS., Conclusions: MiRNA acts as a novel regulator and contributes to FNS-induced neuroprotection. Our study provides a better understanding of neuroprotection induced by FNS.
- Published
- 2015
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40. MicroRNA-29c Correlates with Neuroprotection Induced by FNS by Targeting Both Birc2 and Bak1 in Rat Brain after Stroke.
- Author
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Huang LG, Li JP, Pang XM, Chen CY, Xiang HY, Feng LB, Su SY, Li SH, Zhang L, and Liu JL
- Subjects
- Analysis of Variance, Animals, Baculoviral IAP Repeat-Containing 3 Protein, Brain drug effects, Brain metabolism, Brain Infarction drug therapy, Brain Infarction etiology, Disease Models, Animal, Gene Expression Regulation drug effects, In Situ Nick-End Labeling, Inhibitor of Apoptosis Proteins genetics, Male, MicroRNAs antagonists & inhibitors, Mutation genetics, Nervous System Diseases drug therapy, Nervous System Diseases etiology, Oligonucleotides, Antisense pharmacology, RNA, Messenger metabolism, Rats, Rats, Sprague-Dawley, Stroke complications, Stroke metabolism, Stroke pathology, bcl-2 Homologous Antagonist-Killer Protein genetics, Cerebellar Nuclei physiology, Deep Brain Stimulation methods, Inhibitor of Apoptosis Proteins metabolism, MicroRNAs metabolism, Stroke therapy, bcl-2 Homologous Antagonist-Killer Protein metabolism
- Abstract
Aims: Studies showed fastigial nucleus stimulation (FNS) reduced brain damage, but the mechanisms of neuroprotection induced by FNS were not entirely understood; MicroRNAs are noncoding RNA molecules that regulate gene expression in a posttranscriptional manner, but their functional consequence in response to ischemia-reperfusion (IR) remains unknown. We investigated the role of microRNA-29c in the neuroprotection induced by FNS in rat., Methods: The IR rat models were conducted 1 day after FNS. Besides, miR-29c antagomir (or agomir or control) was infused to the left intracerebroventricular 1 day before IR models were conducted. We detected differential expression of Birc2 mRNA (also Bak1mRNA and miR-29c) level among different groups by RT-qPCR. The differential expression of Birc2 protein (also Bak1 protein) level among different groups was surveyed via Western blot. The neuroprotective effects were assessed by infarct volume, neurological deficit, and apoptosis., Results: MiR-29c was decreased after FNS. Moreover, miR-29c directly bound to the predicted 3'-UTR target sites of Birc2 and Bak1 genes. Furthermore, over-expression of miR-29c effectively reduced Birc2 (also Bak1) mRNA and protein levels, increased infarct volume and apoptosis, and deteriorated neurological outcomes, whereas down-regulation played a neuroprotective role., Conclusions: MiR-29c correlates with the neuroprotection induced by FNS by negatively regulating Birc2 and Bak1., (© 2015 John Wiley & Sons Ltd.)
- Published
- 2015
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41. Amino acid sequence motifs essential for P0-mediated suppression of RNA silencing in an isolate of potato leafroll virus from Inner Mongolia.
- Author
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Zhuo T, Li YY, Xiang HY, Wu ZY, Wang XB, Wang Y, Zhang YL, Li DW, Yu JL, and Han CG
- Subjects
- Amino Acid Sequence, Argonaute Proteins, China, Conserved Sequence, F-Box Motifs, Gene Expression Regulation, Plant, Luteoviridae genetics, Molecular Sequence Data, Mutation, Plant Leaves genetics, Plant Leaves metabolism, Plant Leaves virology, Plant Proteins genetics, Plant Proteins metabolism, Plants, Genetically Modified, RNA Interference, S-Phase Kinase-Associated Proteins genetics, S-Phase Kinase-Associated Proteins metabolism, Sequence Alignment, Nicotiana genetics, Nicotiana metabolism, Two-Hybrid System Techniques, Viral Proteins metabolism, Luteoviridae metabolism, Plant Diseases virology, RNA, Small Interfering metabolism, Solanum tuberosum virology, Nicotiana virology, Viral Proteins genetics
- Abstract
Polerovirus P0 suppressors of host gene silencing contain a consensus F-box-like motif with Leu/Pro (L/P) requirements for suppressor activity. The Inner Mongolian Potato leafroll virus (PLRV) P0 protein (P0(PL-IM)) has an unusual F-box-like motif that contains a Trp/Gly (W/G) sequence and an additional GW/WG-like motif (G139/W140/G141) that is lacking in other P0 proteins. We used Agrobacterium infiltration-mediated RNA silencing assays to establish that P0(PL-IM) has a strong suppressor activity. Mutagenesis experiments demonstrated that the P0(PL-IM) F-box-like motif encompasses amino acids 76-LPRHLHYECLEWGLLCG THP-95, and that the suppressor activity is abolished by L76A, W87A, or G88A substitution. The suppressor activity is also weakened substantially by mutations within the G139/W140/G141 region and is eliminated by a mutation (F220R) in a C-terminal conserved sequence of P0(PL-IM). As has been observed with other P0 proteins, P0(PL-IM) suppression is correlated with reduced accumulation of the host AGO1-silencing complex protein. However, P0(PL-IM) fails to bind SKP1, which functions in a proteasome pathway that may be involved in AGO1 degradation. These results suggest that P0(PL-IM) may suppress RNA silencing by using an alternative pathway to target AGO1 for degradation. Our results help improve our understanding of the molecular mechanisms involved in PLRV infection.
- Published
- 2014
- Full Text
- View/download PDF
42. PI3K-Akt/eNOS in remote postconditioning induced by brief pulmonary ischemia.
- Author
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Tang YH, Yang JS, Xiang HY, and Xu JJ
- Subjects
- Animals, Creatine Kinase blood, Disease Models, Animal, Lung pathology, Male, Malondialdehyde blood, Myocardial Reperfusion Injury pathology, NG-Nitroarginine Methyl Ester pharmacology, Nitric Oxide Synthase Type III antagonists & inhibitors, Rabbits, Superoxide Dismutase blood, rho-Associated Kinases metabolism, Ischemic Preconditioning methods, Lung blood supply, Lung metabolism, Myocardial Reperfusion Injury metabolism, Myocardial Reperfusion Injury prevention & control, Nitric Oxide Synthase Type III metabolism, Phosphatidylinositol 3-Kinases metabolism, Proto-Oncogene Proteins c-akt metabolism
- Abstract
Purpose: Postconditioning, a series of brief ischemia-reperfusion sequences given before an ischemic heart undergoes sustained reperfusion, has been shown to lessen ischemia/reperfusion injury. The current study establishes a rabbit model of myocardial ischemia-reperfusion and studied the effects of pulmonary remote postconditioning in this model., Methods: Serum levels of creatine kinase (CK), superoxide dismutase (SOD), and malondialdehyde (MDA), protein expression of endothelial nitric oxide synthase (eNOS), Rho kinase (ROCK- 2), and protein kinase B (Akt) in myocardial cells and the apoptosis index of myocardial cells were examined., Results: Pulmonary remote postconditioning decreased CK, significantly decreased MDA, and increased SOD. Postconditioning significantly increased eNOS protein expression. Administration of eNOS inhibitor, L-NAME, dramatically suppressed the postconditioning-induced eNOS protein expression and serum SOD level, but significantly increased MDA level. The two longer sessions of postconditioning increased Akt, although this increase was not accompanied by changes in levels of the Akt inhibitor, ROCK-2. Blocking eNOS activity with L-NAME had no visible effect on either Akt or ROCK-2., Conclusion: Our results suggest a role for Akt in remote postconditioning-induced myocardial protection, but do not support an involvement of eNOS in Akt-mediated action.
- Published
- 2014
- Full Text
- View/download PDF
43. Discovery and Characterization of a Novel Carlavirus Infecting Potatoes in China.
- Author
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Li YY, Zhang RN, Xiang HY, Abouelnasr H, Li DW, Yu JL, McBeath JH, and Han CG
- Subjects
- Antibodies, Viral immunology, Antibodies, Viral metabolism, Capsid Proteins genetics, Capsid Proteins immunology, Capsid Proteins metabolism, Carlavirus classification, Carlavirus isolation & purification, China, DNA, Complementary chemistry, DNA, Complementary metabolism, Microscopy, Electron, Phylogeny, Plant Diseases virology, RNA, Viral genetics, RNA, Viral isolation & purification, RNA, Viral metabolism, Real-Time Polymerase Chain Reaction, Sequence Analysis, DNA, Carlavirus genetics, Genome, Viral, Solanum tuberosum virology
- Abstract
A new carlavirus, tentatively named Potato virus H (PVH), was found on potato plants with mild symptoms in Hohhot, Inner Mongolia Autonomous Region, China. PVH was confirmed by genome sequencing, serological reactions, electron microscopy, and host index assays. The PVH particles were filamentous and slightly curved, with a modal length of 570 nm. Complete RNA genomic sequences of two isolates of PVH were determined using reverse transcription-PCR (RT-PCR) and the 5' rapid amplification of cDNA ends (5' RACE) method. Sequence analysis revealed that PVH had the typical genomic organization of members of the genus Carlavirus, with a positive-sense single-stranded genome of 8410 nt. It shared coat protein (CP) and replicase amino acid sequence identities of 17.9-56.7% with those of reported carlaviruses. Phylogenetic analyses based on the protein-coding sequences of replicase and CP showed that PVH formed a distinct branch, which was related only distantly to other carlaviruses. Western blotting assays showed that PVH was not related serologically to other potato carlaviruses (Potato virus S, Potato virus M, and Potato latent virus). PVH systemically infected Nicotianaglutinosa but not Nicotiana tabacum, Nicotianabenthamiana, or Chenopodiumquinoa, which is in contrast with the other potato carlaviruses. These results support the classification of PVH as a novel species in the genus Carlavirus. Preliminary results also indicated that a cysteine-rich protein encoded by the smallest ORF located in the 3' proximal region of the genome suppressed local RNA silencing and enhanced the pathogenicity of the recombinant PVX.
- Published
- 2013
- Full Text
- View/download PDF
44. Disability, home physical environment and non-fatal injuries among young children in China.
- Author
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Zhu HP, Xia X, Xiang HY, Yu CH, and Du YK
- Subjects
- Adolescent, Child, Child, Preschool, China epidemiology, Demography, Female, Humans, Infant, Logistic Models, Male, Prevalence, Disabled Children statistics & numerical data, Wounds and Injuries epidemiology
- Abstract
Objectives: We compared the patterns of medically attended injuries between children with and without disabilities and explored the residential environment risks in five counties of Hubei Province in the People's Republic of China by a 1:1 matched case-control study based on the biopsychosocial model of the International Classification of Functioning, Disability and Health--ICF., Methods: 1201 children aged 1-14 with disabilities and 1201 their healthy counterparts matched as having the same gender, same age, and lived in the same neighborhood were recruited in our study. Characteristics of injuries in the past 12 months were compared between children with and without disabilities. The associations among disability status, home environment factors and injuries were examined in logistic regression analysis taking into account sociodemographic factors., Results: Children with disabilities had a significantly higher prevalence of injury than children without disabilities (10.2% vs. 4.4%; P<.001). The two groups differed significantly in terms of number of injury episodes, injury place and activity at time of injury. Falls were the leading mechanism of injury regardless of disability status. Most of the injury events happened inside the home and leisure activities were the most reported activity when injured for both groups. The univariate OR for injury was 4.46 (2.57-7.74) for the disabled children compared with the non-disabled children. Disabled children whose family raised cat/dog(s) were 76% more likely to be injured during the last 12 months (OR = 1.76; 95% CI = 1.02, 3.02), comparing with those whose family did not have any cat/dog. And for children without disabilities, those whose family had cat/dog(s) were over 3 times more likely to having injuries comparing with those whose family did not have any cat/dog., Conclusions: Children with disabilities had a significantly increased risk for injury. Interventions to prevent residential injury are an important public health priority in children with disabilities.
- Published
- 2012
- Full Text
- View/download PDF
45. Ring structure amino acids affect the suppressor activity of melon aphid-borne yellows virus P0 protein.
- Author
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Han YH, Xiang HY, Wang Q, Li YY, Wu WQ, Han CG, Li DW, and Yu JL
- Subjects
- Amino Acid Sequence, Amino Acid Substitution, Amino Acids chemistry, Animals, Aphids virology, Base Sequence, China, Cucurbitaceae virology, DNA Primers genetics, DNA, Viral genetics, Genes, Viral, Green Fluorescent Proteins genetics, Insect Vectors virology, Luteoviridae pathogenicity, Molecular Sequence Data, Mutagenesis, Site-Directed, Mutant Proteins chemistry, Mutant Proteins genetics, Mutant Proteins physiology, Plants, Genetically Modified, RNA, Small Interfering genetics, Sequence Homology, Amino Acid, Nicotiana genetics, Nicotiana virology, Viral Proteins genetics, Luteoviridae genetics, Luteoviridae physiology, RNA Interference, Viral Proteins chemistry, Viral Proteins physiology
- Abstract
Melon aphid-borne yellows virus (MABYV) is a newly identified polerovirus occurring in China. Here, we demonstrate that the MABYV encoded P0 (P0(MA)) protein is a strong suppressor of post-transcriptional gene silencing (PTGS) with activity comparable to tobacco etch virus (TEV) HC-Pro. In addition we have shown that the LP F-box motif present at the N-terminus of P0(MA) is required for suppressor activity. Detailed mutational analyses on P0(MA) revealed that changing the conserved Trp 212 with non-ring structured amino acids altered silencing suppressor functions. Ala substitutions at positions 12 and 211 for Phe had no effect on P0 suppression-activity, whereas Arg and Glu substitutions had greatly decreased suppressor activity. Furthermore, substitutions targeting Phe at position 30 also resulted in reduced P0 suppression-activity. Altogether, these results suggest that ring structured Trp/Phe residues in P0 have important roles in suppressor activity., (Copyright © 2010 Elsevier Inc. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
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