43 results on '"Denghong Zhang"'
Search Results
2. Implantable cardiac monitor and leadless pacemaker in the management of syncope due to intermittent high-degree atrioventricular block: a case report
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Nian Tang, Xiaoxiao Chen, Denghong Zhang, and Hongfei Li
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Implantable ECG event monitor ,Leadless atrioventricular synchronous pacemaker micra AV ,High atrioventricular block ,Surgery ,RD1-811 ,Anesthesiology ,RD78.3-87.3 - Abstract
Abstract Background Lead dislodgements, tricuspid valve failure, and wound infections are prominent issues addressed by leadless pacemakers (LPM). These devises have emerged as viable alternatives to conventional transvenous pacemakers. LPMs offer minimized complications and effective pacing, particularly beneficial for elderly patients with a low body mass index (BMI) who are at heightened infection of risk. The Micra AV leadless pacemaker was released in the US in 2020, featuring a VDD pacing mode akin to conventional pacemakers. It senses atrial activity to pace ventricular beats while maintaining the natural atrioventricular activation sequence. Micra AV achieves atrioventricular synchronization through mechanical sensing principles. Ongoing research aims to assess its efficacy, implantation feasibility, and clinical safety. Case presentation An 83-year-old man with a history of syncope was the focus of this case study. An implantable cardiac monitor (ICM) recorded occasional high-degree atrioventricular block in the patient. Subsequently, the Micra AV was implanted via the left femoral vein, and its settings were adjusted in accordance with data obtained from the ICM. No significant issues regarding pacing threshold or impedance were found during the follow-up examinations post-surgery. Importantly, the patient experienced a noticeable reduction in symptoms compared to before the implantation. Discussion This case underscores the significance of ICM monitoring in elucidating cardiac events leading to syncope and guiding appropriate treatment. It also highlights the successful outcomes and reliable implantation of the Micra AV for managing high-degree atrioventricular block. This study contributes to the growing body of evidence supporting the adoption of leadless pacemakers as a viable option for patients requiring cardiac pacing, particularly those vulnerable to complications associated with traditional pacemakers. It provides real-world evidence of Micra AV’s efficacy and safety, further validating its role in clinical practice.
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- 2024
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3. Beneficial effects of upgrading to His-Purkinje system pacing in patients with pacing-induced cardiomyopathy: a systematic review and meta-analysis
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Nian Tang, Xiaoxiao Chen, Hongfei Li, and Denghong Zhang
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His-purkinje system packing ,Left bundle branch pacing ,Pacing-induced cardiomyopathy ,Systematic review ,Meta-analysis ,Medicine ,Biology (General) ,QH301-705.5 - Abstract
Background The purpose of this study was to evaluate the effectiveness of His-Purkinje system pacing (HPSP) in the management of patients with pace-induced cardiomyopathy (PICM). Methods PubMed, Embase, Web of Science, and the Cochrane Library were searched comprehensively to collect related studies published from the inception of databases to June 1, 2022. R 4.04 software, including the Metafor package, matrix package, and the Meta package, was utilized to conduct the singe-arm meta-analysis. The methodology index for non-randomized studies (MINORS) was used to assess the methodological quality of the included studies. Results A total of seven studies were included, involving 164 PICM patients. The meta-analysis showed that HPSP ameliorated the left ventricular ejection fraction (LVEF) by 13.41% (95% CI [11.21–15.61]), improved the New York Heart Association (NYHA) classification by 1.02 (95% CI [−1.41 to −0.63]), and shortened the QRS duration (QRSd) by 60.85 ms (95% CI [−63.94 to −57.75]), resulting in improved cardiac functions in PICM patients. Besides, HPSP reversed the ventricular remodeling, with a 32.46 ml (95% CI [−53.18 to −11.75]) decrease in left ventricular end systolic volume (LVESV) and a 5.93 mm (95% CI [−7.68 to −4.19]) decrease in left ventricular end-diastolic dimension (LVEDD). HPSP also showed stable electrical parameters of pacemakers, with a 0.07 V (95% CI [0.01–0.13]) increase in pacing threshold, a 0.02 mV (95% CI [−0.85 to 0.90]) increase in sensed R-wave amplitude, and a 31.12 Ω reduction in impedance (95% CI [−69.62 to 7.39]). Compared with LBBP, HBP improved LVEF by 13.28% (95% CI [−11.64 to 14.92]) vs 14.43% (95% CI [−13.01 to 15.85]), ameliorated NHYA classification by 1.18 (95% CI [−1.97 to −0.39]) vs 0.95 (95% CI [−1.33 to −0.58]), shortened QRSd by 63.16 ms (95% CI [−67.00 to −59.32]) vs 57.98 ms (95% CI [−62.52 to −53.25]), and decreased LVEDD by 4.12 mm (95% CI [−5.79 to −2.45]) vs 6.26 mm (95% CI [−62.52 to −53.25]). The electrical parameters of the pacemaker were stable in both groups. Conclusions This meta-analysis showed that HPSP could significantly improve cardiac function, promote reverse remodeling, and provide stable electrical parameters of pacemakers for PICM patients.
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- 2023
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4. Collisional-radiative modeling for the EUV spectrum of W40+-W42+ions
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Lirong Lei, Xiaobin Ding, Cunqiang Wu, Denghong Zhang, Ling Zhang, Fengling Zhang, Ke Yao, Yang Yang, Yunqing Fu, and Chenzhong Dong
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collisional-radiative model ,tungsten ions ,plasma spectrum ,Science ,Physics ,QC1-999 - Abstract
The wavelengths and transition rates of W ^40+ -W ^42+ ions within the range of 40–140 Å, have been calculated using the Flexible Atomic Code of the Dirac-Fock-Slater method with a central potential. We investigated the charge state distribution of W ^38+ -W ^45+ ions at different temperatures by constructing an appropriate rate equation and demonstrate the importance of the dielectronic recombination process. Additionally, we simulated the emission spectra of W ^40+ -W ^42+ ions in a Tokamak plasma environment using collisional-radiative modeling. Our findings demonstrate strong agreement with experimental results and other related theoretical investigations. Finally, we propose certain pairs of transition lines as diagnostic tools for plasma temperature and density, leveraging the correlation between line intensity ratio and electron temperature and density.
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- 2024
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5. Oral iron supplementation in patients with heart failure: a systematic review and meta‐analysis
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Zhiping Song, Mingyang Tang, Gang Tang, Guoqi Fu, Dengke Ou, Fengyou Yao, Xingzhi Hou, and Denghong Zhang
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Heart failure ,Oral iron ,Iron deficiency ,Anaemia ,Efficacy ,Safety ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
Abstract Aims This review aimed to assess whether oral iron supplementation in a chronic heart failure (HF) population with iron deficiency (ID) or mild anaemia is safe and effective according to evidence‐based medicine. Methods We retrieved 1803 records from the PubMed, Embase, and the Cochrane Library databases from 1 January 1991 to 15 September 2021. The clinical outcome of oral iron supplementation for ID anaemia in patients with HF was the primary endpoint. The primary safety measures included adverse events and all‐cause mortality, and efficacy measures included transferrin saturation (Tsat), ferritin levels, and the 6‐min walk test (6MWT). The rate ratio (RR) was used to pool the efficacy measures. Results Five randomized controlled trials that compared oral iron treatment for patients with the placebo group and included a combined total of 590 participants were analysed. No significant difference was found in all‐cause death between oral iron treatment and placebo groups (RR = 0.77; 95% confidence intervals (CI), 0.46–1.29, Z = 0.98; P = 0.33). However, adverse events were not significantly higher in the iron treatment group (RR = 0.83; 95% CI, 0.60–1.16, Z = 1.07; P = 0.28). In addition, ferritin levels and Tsat were slightly increased after iron complex administration in patients with HF but were not statistically significant (ferritin: mean difference [MD] = 2.70, 95% CI, –2.41 to 7.81, Z = 1.04; P = 0.30; Tsat: MD = 27.42, 95% CI, –4.93 to 59.78, Z = 1.66; P = 0.10). No significant difference was found in exercise capacity, as indicated by the 6MWT results (MD = 59.60, 95% CI, –17.89 to 137.08, Z = 1.51; P = 0.13). We also analysed two non‐randomized controlled trials with follow‐up results showing that oral iron supplementation increased serum iron levels (MD = 28.87, 95% CI, 1.62–56.12, Z = 2.08; P = 0.04). Conclusions Based on the current findings, oral iron supplementation can increase serum iron levels in patients with HF and ID or mild anaemia but does not improve Tsat and 6MWT. In addition, oral iron supplementation is relatively safe.
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- 2022
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6. Comparative proteomics of three Chinese potato cultivars to improve understanding of potato molecular response to late blight disease
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Chunfang Xiao, Mengling Huang, Jianhua Gao, Zhen Wang, Denghong Zhang, Yuanxue Zhang, Lei Yan, Xiao Yu, Bo Li, and Yanfen Shen
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Comparative proteomics ,Potato cultivars ,Phytophthora infestans ,Late blight disease ,Hypersensitive response ,Susceptible ,Biotechnology ,TP248.13-248.65 ,Genetics ,QH426-470 - Abstract
Abstract Background Late blight disease (LBD) caused by the pathogen Phytophthora infestans (PI), is the most devastating disease limiting potato (Solanum tuberosum) production globally. Currently, this disease pathogen is re-emerging and appearing in new areas at a very high intensity. A better understanding of the natural defense mechanisms against PI in different potato cultivars especially at the protein level is still lacking. Therefore, to elucidate potato proteome response to PI, we investigated changes in the proteome and leaf morphology of three potato cultivars, namely; Favorita (FA), Mira (MA), and E-malingshu N0.14 (E14) infected with PI by using the iTRAQ-based quantitative proteomics analysis. Results A total of 3306 proteins were found in the three potato genotypes, and 2044 proteins were quantified. Cluster analysis revealed MA and E14 clustered together separately from FA. The protein profile and related functions revealed that the cultivars shared a typical hypersensitive response to PI, including induction of elicitors, oxidative burst, and suppression of photosynthesis in the potato leaves. Meanwhile, MA and E14 deployed additional specific response mechanism different from FA, involving high induction of protease inhibitors, serine/threonine kinases, terpenoid, hormone signaling, and transport, which contributed to MA tolerance of LBD. Furthermore, inductions of pathogenesis-related proteins, LRR receptor-like kinases, mitogen-activated protein kinase, WRKY transcription factors, jasmonic acid, and phenolic compounds mediate E14 resistance against LBD. These proteins were confirmed at the transcription level by a quantitative polymerase chain reaction and at the translation level by western-blot. Conclusions We found several proteins that were differentially abundant among the cultivars, that includes common and cultivar specific proteins which highlighted similarities and significant differences between FA, MA, and E14 in terms of their defense response to PI. Here the specific accumulation of mitogen-activated protein kinase, Serine/threonine kinases, WRKY transcription played a positive role in E14 immunity against PI. The candidate proteins identified reported in this study will form the basis of future studies and may improve our understanding of the molecular mechanisms of late blight disease resistance in potato.
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- 2020
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7. Molecular and cellular mechanisms underlying the pathogenesis of Alzheimer’s disease
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Tiantian Guo, Denghong Zhang, Yuzhe Zeng, Timothy Y. Huang, Huaxi Xu, and Yingjun Zhao
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Alzheimer’s disease ,Aβ ,Tau ,Microglia ,Astrocyte ,Neurology. Diseases of the nervous system ,RC346-429 ,Geriatrics ,RC952-954.6 - Abstract
Abstract Alzheimer’s disease (AD) is the most common neurodegenerative disorder seen in age-dependent dementia. There is currently no effective treatment for AD, which may be attributed in part to lack of a clear underlying mechanism. Studies within the last few decades provide growing evidence for a central role of amyloid β (Aβ) and tau, as well as glial contributions to various molecular and cellular pathways in AD pathogenesis. Herein, we review recent progress with respect to Aβ- and tau-associated mechanisms, and discuss glial dysfunction in AD with emphasis on neuronal and glial receptors that mediate Aβ-induced toxicity. We also discuss other critical factors that may affect AD pathogenesis, including genetics, aging, variables related to environment, lifestyle habits, and describe the potential role of apolipoprotein E (APOE), viral and bacterial infection, sleep, and microbiota. Although we have gained much towards understanding various aspects underlying this devastating neurodegenerative disorder, greater commitment towards research in molecular mechanism, diagnostics and treatment will be needed in future AD research.
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- 2020
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8. Correction: Wang et al. Exploration of the Inhibitory Potential of Varespladib for Snakebite Envenomation. Molecules 2018, 23, 391
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Yiding Wang, Jing Zhang, Denghong Zhang, Huixiang Xiao, Shengwei Xiong, and Chunhong Huang
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n/a ,Organic chemistry ,QD241-441 - Abstract
The authors would like to correct an error in the original publication [...]
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- 2022
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9. Quantitative Proteomics of Potato Leaves Infected with Phytophthora infestans Provides Insights into Coordinated and Altered Protein Expression during Early and Late Disease Stages
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Chunfang Xiao, Jianhua Gao, Yuanxue Zhang, Zhen Wang, Denghong Zhang, Qiaoling Chen, Xingzhi Ye, Yi Xu, Guocai Yang, Lei Yan, Qun Cheng, Jiaji Chen, and Yanfen Shen
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late blight disease ,potato proteomics ,Phytophthora infestans ,Sarpo Mira ,early and late disease stages ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
In order to get a better understanding of protein association during Solanum tuberosum (cv. Sarpo Mira)–Phytophthora infestans incompatible interaction, we investigated the proteome dynamics of cv. Sarpo Mira, after foliar application of zoospore suspension from P. infestans isolate, at three key time-points: zero hours post inoculation (hpi) (Control), 48 hpi (EI), and 120 hpi (LI); divided into early and late disease stages by the tandem mass tagging (TMT) method. A total of 1229 differentially-expressed proteins (DEPs) were identified in cv. Sarpo Mira in a pairwise comparison of the two disease stages, including commonly shared DEPs, specific DEPs in early and late disease stages, respectively. Over 80% of the changes in protein abundance were up-regulated in the early stages of infection, whereas more DEPs (61%) were down-regulated in the later disease stage. Expression patterns, functional category, and enrichment tests highlighted significant coordination and enrichment of cell wall-associated defense response proteins during the early stage of infection. The late stage was characterized by a cellular protein modification process, membrane protein complex formation, and cell death induction. These results, together with phenotypic observations, provide further insight into the molecular mechanism of P. infestans resistance in potatos.
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- 2019
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10. Classification of hyperspectral images based on fused 3D inception and 3D-2D hybrid convolution.
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Jingke Shen, Denghong Zhang, Guanghui Dong, Duixiong Sun, Xiyin Liang, and Maogen Su
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- 2024
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11. Inactivation of Venom PLA2 Alleviates Myonecrosis and Facilitates Muscle Regeneration in Envenomed Mice: A Time Course Observation
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Huixiang Xiao, Haoran Li, Denghong Zhang, Yuanyuan Li, Shimin Sun, and Chunhong Huang
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varespladib ,muscle regeneration ,Deinagkistrodon acutus ,fibrosis ,Organic chemistry ,QD241-441 - Abstract
Snake venom is a complex cocktail of toxins which induces a series of clinical and pathophysiological manifestations in victims, including severe local tissue damage and systemic alterations. Deinagkistrodon acutus (D. acutus) ranks among the “big four” life-threatening venomous species in China, whose venom possesses strong myotoxicity and hematotoxicity that often lead to permanent disability or muscle atrophy. Varespladib, an inhibitor of mammalian phospholipase A2 (PLA2), has been recently reproposed as an effective antidote against snakebite envenomation. The present study aimed at evaluating the protective role of varespladib on muscle regeneration in envenomed mice. Mice were grouped and subjected to inoculation with D. acutus venom or a mixture of venom and varespladib or control vehicle in the gastrocnemius muscle. Local injuries including hemorrhage, myonecrosis, ulceration, and systemic damages including general dysfunction, visceral failure, and inflammatory responses were observed at 1, 3, 7, 14, and 21 days. The results indicated that most of the muscle myonecrosis and hemorrhage were alleviated by varespladib. Besides, the pretreated mice recovered rapidly with lesser atrophy and muscle fibrosis. In conclusion, the findings of the present study suggested that varespladib is an effective antidote that could neutralize D. acutus venom and allow for earlier and improved rehabilitation outcome.
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- 2018
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12. Exploration of the Inhibitory Potential of Varespladib for Snakebite Envenomation
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Yiding Wang, Jing Zhang, Denghong Zhang, Huixiang Xiao, Shengwei Xiong, and Chunhong Huang
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antivenom ,myotoxicity ,phospholipase A2 ,varespladib ,Organic chemistry ,QD241-441 - Abstract
Phospholipase A2s (PLA2) is a major component of snake venom with diverse pathologic toxicities and, therefore, a potential target for antivenom therapy. Varespladib was initially designed as an inhibitor of mammal PLA2s, and was recently repurposed to a broad-spectrum inhibitor of PLA2 in snake venom. To evaluate the protective abilities of varespladib to hemorrhage, myonecrosis, and systemic toxicities that are inflicted by different crude snake venoms, subcutaneous ecchymosis, muscle damage, and biochemical variation in serum enzymes derived from the envenomed mice were determined, respectively. Varespladib treatment showed a significant inhibitory effect to snake venom PLA2, which was estimated by IC50 in vitro and ED50 in vivo. In animal models, the severely hemorrhagic toxicity of D. acutus and A. halys venom was almost fully inhibited after administration of varespladib. Moreover, signs of edema in gastrocnemius muscle were remarkably attenuated by administration of varespladib, with a reduced loss of myonecrosis and desmin. Serum levels of creatine kinase, lactate dehydrogenase isoenzyme 1, aspartate transaminase, and alanine transaminase were down-regulated after treatment with varespladib, which indicated the protection to viscera injury. In conclusion, varespladib may be a potential first-line drug candidate in snakebite envenomation first aid or clinical therapy.
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- 2018
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13. Extreme ultraviolet 4p and 4d excitation spectra in laser-produced Ag plasmas
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Maijuan Li, Maogen Su, Haoyang Li, Guoding Zhang, Qi Min, Shiquan Cao, Duixiong Sun, Denghong Zhang, and Chenzhong Dong
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Radiation ,Spectroscopy ,Atomic and Molecular Physics, and Optics - Published
- 2023
14. Energy Level and Transition Properties of Double K Hole States for He-Like Ions ( [[Equation]] )
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Cunqiang Wu, Xiaobin Ding, Mingxin Cao, Denghong Zhang, Mingwu Zhang, Yingli Xue, Deyang Yu, and Chenzhong Dong
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- 2023
15. A Case of Löffler Endocarditis Complicated with Listeria Sepsis
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Fengyou, Yao, Shilan, Liu, Qian, Yu, Luyong, Huang, Denghong, Zhang, Yong, Li, Mingjian, Lang, and Jingjing, Hu
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Endocarditis ,Listeria ,Sepsis ,Humans ,Endocarditis, Bacterial - Published
- 2022
16. Downregulating PTBP1 fails to convert astrocytes into hippocampal neurons and to alleviate symptoms in Alzheimer’s mouse models
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Tiantian Guo, Xinjia Pan, Guangtong Jiang, Denghong Zhang, Jinghui Qi, Lin Shao, Zhanxiang Wang, Huaxi Xu, and Yingjun Zhao
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nervous system ,General Neuroscience ,Research Articles - Abstract
Conversion of astroglia into functional neurons has been considered a promising therapeutic strategy for neurodegenerative diseases. Recent studies reported that downregulation of the RNA binding protein, polypyrimidine tract-binding protein 1 (PTBP1), converts astrocytes into neurons in situ in multiple mouse brain regions, consequently improving pathologic phenotypes associated with Parkinson's disease, RGC loss, and aging. Here, we demonstrate that PTBP1 downregulation using an astrocyte-specific AAV-mediated shRNA system fails to convert hippocampal astrocytes into neurons in both male and female wild-type (WT) and β-amyloid (5×FAD) and tau (PS19) Alzheimer's disease (AD) mouse models and fails to reverse synaptic/cognitive deficits and AD-associated pathology in male mice. Similarly, PTBP1 downregulation cannot convert astrocytes into neurons in the striatum and substantia nigra in both male and female WT mice. Together, our study suggests that cell fate conversion strategy for neurodegenerative disease therapy through manipulating one single gene, such as PTBP1, warrants more rigorous scrutiny. SIGNIFICANCE STATEMENT Our results do not support some of the recent extraordinary and revolutionary claims that resident astrocytes can be directly and efficiently converted into neurons. Our study is critical for the field of neural regeneration and degeneration. In addition, our study is financially important because it may prevent other researchers/organizations from wasting a vast amount of time and resources on relevant investigations.
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- 2022
17. Real optical imaging simulation of laser-produced aluminum plasmas
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Siqi He, Qi Min, Maogen Su, Haidong Lu, Yanhong Wu, Shiquan Cao, Duixiong Sun, Denghong Zhang, and Chenzhong Dong
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Atomic and Molecular Physics, and Optics - Abstract
We developed a post-processing optical imaging model based on two-dimensional axisymmetric radiation hydrodynamics. Simulation and program benchmarks were performed using laser-produced Al plasma optical images obtained via transient imaging. The emission profiles of a laser-produced Al plasma plume in air at atmospheric pressure were reproduced, and the influence of plasma state parameters on radiation characteristics were clarified. In this model, the radiation transport equation is solved on the real optical path, which is mainly used to study the radiation of luminescent particles during plasma expansion. The model outputs consist of the electron temperature, particle density, charge distribution, absorption coefficient, and corresponding spatio-temporal evolution of the optical radiation profile. The model helps with understanding element detection and quantitative analysis of laser-induced breakdown spectroscopy.
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- 2023
18. Extreme ultraviolet spectral characteristic analysis of highly charged ions in laser-produced Cu plasmas
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Maijuan LI, Maogen SU, Haoyang LI, Qi MIN, Shiquan CAO, Duixiong SUN, Denghong ZHANG, and Chenzhong DONG
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Condensed Matter Physics - Abstract
This paper reports the results of spectral measurements and a theoretical analysis of the temporal and spatial evolution of laser-produced Cu plasma in vacuum in the range of 8–14 nm. The time dependence of the extreme ultraviolet band spectrum at different positions near the target surface was obtained and found to be dominated by three broad-band features. The 3p and 3d excitations of Cu5+–Cu9+ ions were calculated using the Hartree–Fock theory with configuration interactions. The characteristics of the spectral line distribution for the 3p–nd and 3d–nf transition arrays were analyzed. Based on the steady-state collisional radiation model and the normalized Boltzmann distribution, the complex spectral structure in the band of 13–14 nm is accurately explained through consistency comparisons and benchmarking between the experimental and theoretical simulation spectra, demonstrating that the structure mainly stems from the overlapping contribution of the 3d–4f and 3p–3d transition arrays for the Cu5+–Cu9+ ions. These results may help in studying the radiation characteristics of isoelectronic series highly-charged ions involving the 3d excitation process.
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- 2023
19. The molecular basis of venom resistance in the non-venomous snake Sinonatrix annularis
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Qi Lian, Denghong Zhang, Kepu Fu, Chunju Liu, Liyun Cao, Kejia Xiong, and Chunhong Huang
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Male ,Proteomics ,Proteome ,Antivenins ,Clinical Biochemistry ,Colubridae ,Cell Biology ,General Medicine ,Biochemistry ,Mass Spectrometry ,Analytical Chemistry ,Mice ,Phospholipases A2 ,Metalloproteases ,Animals ,Rabbits ,Snake Venoms - Abstract
Various snake species and snake predators have natural neutralization against snake toxins, which their antidotal abilities are commonly attributed to the intrinsic inhibitors produced by the liver, e.g., phospholipase A
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- 2021
20. High activity chimeric snake gamma-type phospholipase A2 inhibitor created by DNA shuffling
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Jing Zhang, Denghong Zhang, Ying Xiong, Chunhong Huang, and Shimin Sun
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0301 basic medicine ,Gene isoform ,Elaphe carinata ,biology ,Sequence alignment ,Toxicology ,biology.organism_classification ,complex mixtures ,Molecular biology ,law.invention ,DNA shuffling ,03 medical and health sciences ,030104 developmental biology ,law ,Snake venom ,Sinonatrix annularis ,Gene ,Polymerase chain reaction - Abstract
The gamma-type inhibitor of snake venom phospholipase A2 (PLIγ) is expressed extensively in livers of both venomous and non-venomous snakes. It is not clear why PLIγs from different snake species possess diverse activities. To obtain high activity PLIγs and interpret the sequence-function relationships, we used DNA shuffling to hybridize the PLIγs of Sinonatrix annularis (saPLIγ) and Elaphe carinata (ecPLIγ). Chimera PLIγs (cPLIγ) of ∼550 bp were obtained by a series of gene manipulations including DNase I digestion, primer-free PCR, and PCR amplification with PLIγs primer pair. After successful insertion of cPLIγs into pCANTAB5e phage vector, the transformed TG1 strain of Esherichia coli was achieved. The cPLIγ phage library was produced and panned in a five-pace snake venom-coated immune tube. Three high affinity cPLIγ isoforms survived two rounds of panning. Prokaryote expression by the pET28c vector was employed for production of the three cPLIγs and the two parental PLIγs. These all showed anti-hemorrhage activity with cPLIγ 2 demonstrating superior inhibition to the parent PLIγs. Sequence alignment showed that the three kinds of cPLIγ were produced by gene splicing of S. annularis and E. carinata at different sites. Primary sequence changes brought regional changes in secondary and tertiary structure, which may explain the differences in PLIγ activity.
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- 2018
21. Regioselective Coupling Reactions of Coumarins with Aldehydes or Di-tert-butyl Peroxide (DTBP) through a C(sp2)-H Functionalization Process
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Yingcai Ding, Aihua Zhou, Ben Niu, Zhaogang Bian, Ping Xie, Wannian Zhao, Lei Xu, and Denghong Zhang
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Di-tert-butyl peroxide ,010405 organic chemistry ,Organic Chemistry ,Regioselectivity ,chemistry.chemical_element ,010402 general chemistry ,Coumarin ,01 natural sciences ,Copper ,Peroxide ,Coupling reaction ,0104 chemical sciences ,Catalysis ,chemistry.chemical_compound ,chemistry ,Surface modification ,Organic chemistry ,heterocyclic compounds ,Physical and Theoretical Chemistry - Abstract
Coumarin derivatives are highly valuable compounds in drug discovery. Herein, we have developed two new coupling reactions that involve coumarins and either aldehydes or di-tert-butyl peroxide (DTBP) in the presence of inexpensive copper or iron catalysts. Both of these reactions proceed through a C(sp2)–H functionalization process to regioselectivity generate keto- or methyl-substituted coumarin derivatives in moderate to good yields These coupling reactions will enrich current coumarin chemistry.
- Published
- 2015
22. Treatment of atrial fibrillation with third-degree atrioventricular block by pacing His bundle and left bundle branch
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Denghong Zhang and Xiaoming Huang
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Bundle of His ,left bundle branch pacing ,medicine.medical_specialty ,Cardiac pacing ,medicine.medical_treatment ,Cardiac resynchronization therapy ,third degree atrioventricular block ,Cardiac Resynchronization Therapy ,03 medical and health sciences ,0302 clinical medicine ,His bundle pacing ,Internal medicine ,Atrial Fibrillation ,Left bundle branch ,medicine ,Humans ,Clinical Case Report ,030212 general & internal medicine ,Atrioventricular Block ,Aged ,business.industry ,Third-degree atrioventricular block ,Atrial fibrillation ,General Medicine ,medicine.disease ,030220 oncology & carcinogenesis ,Bundle ,Heart failure ,Cardiology ,Female ,business ,Atrioventricular block ,Research Article - Abstract
Introduction: Substantial advances in cardiac pacing technology have been developed in the past decades. However, efforts to improve pacing technology to achieve physiological electrical activity, such as with cardiac resynchronization therapy, are underway. Permanent His bundle pacing, which directly stimulates the His-Purkinje network and electrically activates both ventricles, simulates physiological electric activity in the heart, and has been considered an ideal pacing strategy to treat arrhythmias. For patients with atrial fibrillation complicated by third-degree atrioventricular block (AVB), permanent His bundle pacing is a better option than conventional right ventricular apical or septal pacing, the latter of which may be associated with risks, such as heart failure. However, His bundle pacing exhibits some shortcomings, including elevated pacing threshold, dislocation, and abnormal sensing. Case presentation: A 69-year-old female patient who had atrial fibrillation (AF) complicated by third-degree AVB and who was treated with permanent His bundle pacing combined with left bundle branch pacing. Diagnosis: AF complicated by third-degree AVB. Interventions: We used the left bundle branch as a backup pacing site to overcome any shortcomings related to permanent His bundle pacing. Outcomes: The patient recovered well without any events. Conclusion: We selected His bundle pacing as the primary pacing, but also used left bundle branch pacing as a backup approach. If His bundle pacing results in an increased sensing threshold, pacing threshold changes, or dislocations, left bundle branch pacing can compensate for dysfunction of permanent deficiencies in His bundle pacing, preserving physiological pacing.
- Published
- 2020
23. Effects of electron correlation and the Breit interaction on one- and two-electron one-photon transitions in double K hole states of He-like ions (10 ≤ Z ≤ 47)*
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Chenzhong Dong, Deyang Yu, Mingxin Cao, Xiaobin Ding, Denghong Zhang, Cunqiang Wu, Yingli Xue, and Mingwu Zhang
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Physics ,Photon ,Electronic correlation ,Atomic Physics (physics.atom-ph) ,Computer Science::Information Retrieval ,FOS: Physical sciences ,General Physics and Astronomy ,Electron ,Atomic physics ,Physics - Atomic Physics ,Ion - Abstract
The x-ray energies and transition rates associated with single and double electron radiative transitions from the double K hole state $2s2p$ to the $1s2s$ and $1s^{2}$ configurations of 11 He-like ions ($10\!\leq\!Z\!\leq\!47$) are evaluated using the fully relativistic multi-configuration Dirac-Fock method. An appropriate electron correlation model is constructed with the aid of the active space method, which allows the electron correlation effects to be studied efficiently. The contributions of electron correlation and the Breit interaction to the transition properties are analyzed in detail. It is found that the two-electron one-photon (TEOP) transition is correlation sensitive. The Breit interaction and electron correlation both contribute significantly to the radiative transition properties of the double K hole state of He-like ions. Good agreement between the present calculation and previous work is achieved. The calculated data will be helpful to future investigations on double K hole decay processes of He-like ions., 9 pages, 2 figures and 4 tables
- Published
- 2020
24. High activity chimeric snake gamma-type phospholipase A
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Shimin, Sun, Denghong, Zhang, Jing, Zhang, Chunhong, Huang, and Ying, Xiong
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Mice ,Liver ,Phospholipase A2 Inhibitors ,Colubridae ,Escherichia coli ,Animals ,Protein Isoforms ,Bacteriophages ,DNA Shuffling ,Hemorrhage ,Amino Acid Sequence ,Sequence Alignment ,Snake Venoms - Abstract
The gamma-type inhibitor of snake venom phospholipase A
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- 2018
25. The inhibitory effect of saPLIγ, a snake sourced PLA
- Author
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Denghong, Zhang, Jingjing, Li, Shimin, Sun, and Chunhong, Huang
- Subjects
Inflammation ,Mice ,Phospholipases A2 ,Cyclooxygenase 2 ,Phospholipase A2 Inhibitors ,Tumor Necrosis Factor-alpha ,Interleukin-1beta ,Colubridae ,Animals ,Carrageenan ,Gene Expression Regulation, Enzymologic ,Snake Venoms - Abstract
SaPLIγ is a natural phospholipase A
- Published
- 2018
26. Exploration of the Inhibitory Potential of Varespladib for Snakebite Envenomation
- Author
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Jing Zhang, Huixiang Xiao, Denghong Zhang, Chunhong Huang, Yiding Wang, and Shengwei Xiong
- Subjects
0301 basic medicine ,Indoles ,Antivenom ,Ecchymosis ,Pharmaceutical Science ,Snake Bites ,Venom ,Pharmacology ,Acetates ,Analytical Chemistry ,chemistry.chemical_compound ,Mice ,Drug Discovery ,Medicine ,Edema ,Creatine Kinase ,biology ,Antivenins ,Alanine Transaminase ,Keto Acids ,Isoenzymes ,Chemistry (miscellaneous) ,Snake venom ,Molecular Medicine ,Female ,antivenom ,myotoxicity ,phospholipase A2 ,varespladib ,Phospholipase A2 Inhibitors ,Myotoxin ,Aspartate transaminase ,complex mixtures ,Article ,lcsh:QD241-441 ,03 medical and health sciences ,lcsh:Organic chemistry ,Crotalid Venoms ,Animals ,Aspartate Aminotransferases ,Physical and Theoretical Chemistry ,Envenomation ,Muscle, Skeletal ,L-Lactate Dehydrogenase ,business.industry ,Organic Chemistry ,Phospholipases A2 ,030104 developmental biology ,chemistry ,Alanine transaminase ,biology.protein ,Varespladib ,business ,Crotalinae - Abstract
Phospholipase A2s (PLA2) is a major component of snake venom with diverse pathologic toxicities and, therefore, a potential target for antivenom therapy. Varespladib was initially designed as an inhibitor of mammal PLA2s, and was recently repurposed to a broad-spectrum inhibitor of PLA2 in snake venom. To evaluate the protective abilities of varespladib to hemorrhage, myonecrosis, and systemic toxicities that are inflicted by different crude snake venoms, subcutaneous ecchymosis, muscle damage, and biochemical variation in serum enzymes derived from the envenomed mice were determined, respectively. Varespladib treatment showed a significant inhibitory effect to snake venom PLA2, which was estimated by IC50 in vitro and ED50 in vivo. In animal models, the severely hemorrhagic toxicity of D. acutus and A. halys venom was almost fully inhibited after administration of varespladib. Moreover, signs of edema in gastrocnemius muscle were remarkably attenuated by administration of varespladib, with a reduced loss of myonecrosis and desmin. Serum levels of creatine kinase, lactate dehydrogenase isoenzyme 1, aspartate transaminase, and alanine transaminase were down-regulated after treatment with varespladib, which indicated the protection to viscera injury. In conclusion, varespladib may be a potential first-line drug candidate in snakebite envenomation first aid or clinical therapy.
- Published
- 2018
27. Genome-Wide Identification of Early-Firing Human Replication Origins by Optical Replication Mapping
- Author
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David M. Gilbert, Saki Chan, Zhiping Weng, Alex Hastie, Denghong Zhang, Chun-Long Chen, Weitao Wang, Nicholas Rhind, Kyle N. Klein, and Tyler M. Borrman
- Subjects
Genetics ,0303 health sciences ,Replication timing ,DNA replication ,Genomics ,Biology ,Origin of replication ,Genome ,Replication (computing) ,03 medical and health sciences ,0302 clinical medicine ,Evolutionary biology ,Replication Initiation ,030220 oncology & carcinogenesis ,ORC1 ,030304 developmental biology - Abstract
The timing of DNA replication is largely regulated by the location and timing of replication origin firing. Therefore, much effort has been invested in identifying and analyzing human replication origins. However, the heterogeneous nature of eukaryotic replication kinetics and the low efficiency of individual origins in metazoans has made mapping the location and timing of replication initiation in human cells difficult. We have mapped early-firing origins in HeLa cells using Optical Replication Mapping, a high-throughput single-molecule approach based on Bionano Genomics genomic mapping technology. The single-molecule nature and 290-fold coverage of our dataset allowed us to identify origins that fire with as little as 1% efficiency. We find sites of human replication initiation in early S phase are not confined to well-defined efficient replication origins, but are instead distributed across broad initiation zones consisting of many inefficient origins. These early-firing initiation zones co-localize with initiation zones inferred from Okazaki-fragment-mapping analysis and are enriched in ORC1 binding sites. Although most early-firing origins fire in early-replication regions of the genome, a significant number fire in late-replicating regions, suggesting that the major difference between origins in early and late replicating regions is their probability of firing in early S-phase, as opposed to qualitative differences in their firing-time distributions. This observation is consistent with stochastic models of origin timing regulation, which explain the regulation of replication timing in yeast.
- Published
- 2017
- Full Text
- View/download PDF
28. Characterization of rhizosphere and endophytic bacterial communities from leaves, stems and roots of medicinal Stellera chamaejasme L
- Author
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Xiaoyan Yang, Denghong Zhang, Bo Qin, Zhiqiang Yan, Xiuzhuang Li, Liming Zeng, Hui Jin, Quan Liu, and Jixiang Chen
- Subjects
DNA, Bacterial ,Firmicutes ,Molecular Sequence Data ,DNA, Ribosomal ,Plant Roots ,Applied Microbiology and Biotechnology ,Microbiology ,Actinobacteria ,RNA, Ribosomal, 16S ,Botany ,Endophytes ,Cluster Analysis ,Phylogeny ,Soil Microbiology ,Ecology, Evolution, Behavior and Systematics ,Rhizosphere ,Bacteria ,Plant Stems ,biology ,Bacteroidetes ,Sequence Analysis, DNA ,biology.organism_classification ,Biota ,Plant Leaves ,Chloroflexi (class) ,Thymelaeaceae ,Proteobacteria ,Soil microbiology - Abstract
A diverse array of bacteria that inhabit the rhizosphere and different plant organs play a crucial role in plant health and growth. Therefore, a general understanding of these bacterial communities and their diversity is necessary. Using the 16S rRNA gene clone library technique, the bacterial community structure and diversity of the rhizosphere and endophytic bacteria in Stellera chamaejasme compartments were compared and clarified for the first time. Grouping of the sequences obtained showed that members of the Proteobacteria (43.2%), Firmicutes (36.5%) and Actinobacteria (14.1%) were dominant in both samples. Other groups that were consistently found, albeit at lower abundance, were Bacteroidetes (2.1%), Chloroflexi (1.9%), and Cyanobacteria (1.7%). The habitats (rhizosphere vs endophytes) and organs (leaf, stem and root) structured the community, since the Wilcoxon signed rank test indicated that more varied bacteria inhabited the rhizosphere compared to the organs of the plant. In addition, correspondence analysis also showed that differences were apparent in the bacterial communities associated with these distinct habitats. Moreover, principal component analysis revealed that the profiles obtained from the rhizosphere and roots were similar, whereas leaf and stem samples clustered together on the opposite side of the plot from the rhizosphere and roots. Taken together, these results suggested that, although the communities associated with the rhizosphere and organs shared some bacterial species, the associated communities differed in structure and diversity.
- Published
- 2014
29. Phytotoxicity mechanisms of two coumarin allelochemicals from Stellera chamaejasme in lettuce seedlings
- Author
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Xiao-Feng He, Hui Jin, Yuhe Sun, Dandan Wang, Hongru Guo, Zhiqiang Yan, Xia Ren, Bo Qin, Denghong Zhang, Haiyan Cui, Le Pan, Xiaoyan Yang, Xiuzhuang Li, and Kai Guo
- Subjects
0106 biological sciences ,0301 basic medicine ,Lipid peroxide ,Physiology ,Plant Science ,Biology ,Umbelliferone ,01 natural sciences ,Lipid peroxidation ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,chemistry ,Botany ,Shoot ,Daphnoretin ,Phytotoxicity ,Weed ,Agronomy and Crop Science ,Allelopathy ,010606 plant biology & botany - Abstract
Stellera chamaejasme, a perennial weed which is an ecological threat, is widely distributed in some grasslands of Central and Eastern Asia. Our previous studies have identified several allelochemicals including two coumarins (umbelliferone and daphnoretin), from S. chamaejasme, and confirmed that allelopathy contributed to the competitive behavior of this weed. In this study, the inhibitory effects of umbelliferone and daphnoretin on lettuce seedlings and the mechanisms of their phytotoxicity were investigated. Results showed that shoot and root elongation and fresh weight of lettuce seedlings were effectively inhibited by umbelliferone in a concentration-dependent manner. Daphnoretin showed a weaker phytotoxicity. Both of the coumarins arrested the mitosis process in lettuce root tips and induced proline overproduction. Additionally, loss of cell viability and overproduction of reactive oxygen species in lettuce root cells were found after treatments with umbelliferone. Moreover, umbelliferone caused lipid peroxidation. These results suggested that umbelliferone displayed stronger phytotoxicity than daphnoretin on lettuce growth, and that the two coumarins had different mechanisms of phytotoxicity. That of daphnoretin was mainly dependent on its inhibitory effects on mitosis. Umbelliferone caused membrane lipid peroxide formation and cell death by inducing ROS overproduction, and impacted cell division, which resulted in growth inhibition of the receptor plant.
- Published
- 2016
30. Phytotoxic Allelochemicals from Roots and Root Exudates of Trifolium pratense
- Author
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Haiyan Cui, Hui Jin, Zhiqiang Yan, Denghong Zhang, Bo Qin, Liqin Lu, Quan Liu, and Rui Xu
- Subjects
Flavonoids ,China ,Pterocarpans ,biology ,Herbicides ,Plant Extracts ,Plant Exudates ,Soil chemistry ,General Chemistry ,Fractionation ,biology.organism_classification ,Heterocyclic Compounds, 4 or More Rings ,Plant Roots ,Pheromones ,Soil ,Glucosides ,Botany ,Arabidopsis thaliana ,Trifolium ,Poa annua ,Phytotoxicity ,General Agricultural and Biological Sciences ,Weed ,Allelopathy ,Legume - Abstract
Trifolium pratense, a widespread legume forage plant, is reported to exhibit phytotoxic activity on other plants, but the active metabolites have not been clarified so far. A bioassay-guided fractionation of the root extracts led to the isolation of five isoflavonoids, which were elucidated by spectroscopic analysis. All of the purified compounds observably showed phytotoxic activities against Arabidopsis thaliana . Moreover, the inhibitory effects were concentration-dependent. The furan ring linked at C-4 and C-2' positions by an oxygen atom and a 1,3-dioxolane at C-4' and C-5' positions are considered to be critical factors for the phytotoxic activity. The concentrations of (6aR,11aR)-maackiain and (6aR,11aR)-trifolirhizin, concluded to be allelochemicals from soil around plants of T. pratense, were determined by HPLC and LC-MS to be 4.12 and 2.37 μg/g, respectively. These allelochemicals, which showed remarkable activities against the weed Poa annua may play an important role in assisting the widespread occurrence of T. pratense in nature.
- Published
- 2013
31. Theoretical estimates of standard electrode potentials for superheavy element Uus( Z =117) in acid solutions
- Author
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ZhiWei Chang, ChenZhong Dong, and DengHong Zhang
- Subjects
Physics ,chemistry ,Standard electrode potential ,chemistry.chemical_element ,Element (category theory) ,Atomic physics ,Ununseptium - Abstract
基于Born-Haber热力学循环理论, 利用多组态Dirac-Fock方法计算的超重元素Uus及其同族元素Cl, Br, I和At的离化势和亲和势及已有的标准电极电势的实验值,拟合得到了Uus的元素电势图. 结果表明: 在酸溶液中Uus的0价态能够稳定存在, 而1-, 1+和5+价态不能稳定存在; 在同族元素中, 随原子序数Z的增大, 0价态和1+态的稳定性逐渐增加, 1-价态的稳定性逐渐降低; 而5+价态的稳定性随原子序数变化并不是单调的. 对于这种稳定性随原子序数变化的规律, 我们从价电子能级的相对位置以及电子电离或亲和的过程作了定性的解释.
- Published
- 2013
32. Characterization of rhizosphere and endophytic fungal communities from roots of Stipa purpurea in alpine steppe around Qinghai Lake
- Author
-
Yuhui Zhao, Xiaoyan Yang, Denghong Zhang, Hui Jin, Bo Qin, Dengxue Lu, Han Rongbing, Zhiqiang Yan, and Xiuzhuang Li
- Subjects
0106 biological sciences ,0301 basic medicine ,Alpine-steppe ,Steppe ,Immunology ,Biology ,Poaceae ,01 natural sciences ,Applied Microbiology and Biotechnology ,Microbiology ,Plant Roots ,03 medical and health sciences ,Soil ,Ascomycota ,Botany ,Genetics ,Endophytes ,Endemism ,Molecular Biology ,Soil Microbiology ,Rhizosphere ,geography ,geography.geographical_feature_category ,Ecology ,Basidiomycota ,Species diversity ,General Medicine ,Lakes ,030104 developmental biology ,Species richness ,Soil microbiology ,010606 plant biology & botany - Abstract
Stipa purpurea is among constructive endemic species in the alpine steppe on the Qinghai–Xizang Plateau. To reveal the fungal community structure and diversity in the rhizosphere and roots of this important grass and to analyze the potential influence of different habitats on the structure of fungal communities, we explored the root endophyte and the directly associated rhizosphere communities of S. purpurea by using internal transcribed spacer rRNA cloning and sequencing methods. We found that the roots of S. purpurea are associated with a diverse consortium of Basidiomycota (59.8%) and Ascomycota (38.5%). Most fungi obtained from rhizosphere soil in S. purpurea have been identified as Ascomycetes, while the high proportion detected in roots were basidiomycetous endophytes. The species richness, diversity, and evenness of fungal assemblages were higher in roots than in the rhizosphere soil. Fungi inhabiting the rhizosphere and roots of S. purpurea are significantly different, and the rhizosphere and endophyte communities are largely independent with little overlap in the dominant phyla or operational taxonomic units. Taken together, these results suggested that a wide variety of fungal communities are associated with the roots and rhizosphere soil of S. purpurea and that the fungal assemblages are strongly influenced by different habitats.
- Published
- 2016
33. ChemInform Abstract: Regioselective Coupling Reactions of Coumarins with Aldehydes or Di-tert-Butyl Peroxide (DTBP) Through a C(sp2)-H Functionalization Process
- Author
-
Lei Xu, Ping Xie, Wannian Zhao, Zhaogang Bian, Denghong Zhang, Ben Niu, Aihua Zhou, and Yingcai Ding
- Subjects
Di-tert-butyl peroxide ,Regioselectivity ,chemistry.chemical_element ,General Medicine ,Coumarin ,Peroxide ,Copper ,Combinatorial chemistry ,Coupling reaction ,Catalysis ,chemistry.chemical_compound ,chemistry ,Surface modification ,heterocyclic compounds - Abstract
Coumarin derivatives are highly valuable compounds in drug discovery. Herein, we have developed two new coupling reactions that involve coumarins and either aldehydes or di-tert-butyl peroxide (DTBP) in the presence of inexpensive copper or iron catalysts. Both of these reactions proceed through a C(sp2)–H functionalization process to regioselectivity generate keto- or methyl-substituted coumarin derivatives in moderate to good yields These coupling reactions will enrich current coumarin chemistry.
- Published
- 2016
34. IκB kinase ε and TANK-binding kinase 1 activate AKT by direct phosphorylation
- Author
-
Bin Zhao, Xiaoduo Xie, Kun-Liang Guan, Denghong Zhang, Cun-Yu Wang, Gianluigi Condorelli, Ming You, and Min Kan Lu
- Subjects
Multidisciplinary ,TANK-binding kinase 1 ,Akt/PKB signaling pathway ,I-Kappa-B Kinase ,Phosphorylation ,Biology ,Protein kinase A ,Protein kinase B ,mTORC2 ,PI3K/AKT/mTOR pathway ,Cell biology - Abstract
AKT activation requires phosphorylation of the activation loop (T308) by 3-phosphoinositide-dependent protein kinase 1 (PDK1) and the hydrophobic motif (S473) by the mammalian target of rapamycin complex 2 (mTORC2). We recently observed that phosphorylation of the AKT hydrophobic motif was dramatically elevated, rather than decreased, in mTOR knockout heart tissues, indicating the existence of other kinase(s) contributing to AKT phosphorylation. Here we show that the atypical IκB kinase ε and TANK-binding kinase 1 (IKKε/TBK1) phosphorylate AKT on both the hydrophobic motif and the activation loop in a manner dependent on PI3K signaling. This dual phosphorylation results in a robust AKT activation in vitro. Consistently, we found that growth factors can induce AKT (S473) phosphorylation in Rictor −/− cells, and this effect is insensitive to mTOR inhibitor Torin1. In IKKε/TBK1 double-knockout cells, AKT activation by growth factors is compromised. We also observed that TBK1 expression is elevated in the mTOR knockout heart tissues, and that TBK1 is required for Ras-induced mouse embryonic fibroblast transformation. Our observations suggest a physiological function of IKKε/TBK1 in AKT regulation and a possible mechanism of IKKε/TBK1 in oncogenesis by activating AKT.
- Published
- 2011
35. MTORC1 regulates cardiac function and myocyte survival through 4E-BP1 inhibition in mice
- Author
-
Denghong, Zhang, Riccardo, Contu, Michael V G, Latronico, Jianlin, Zhang, Jian Ling, Zhang, Roberto, Rizzi, Daniele, Catalucci, Shigeki, Miyamoto, Katherine, Huang, Marcello, Ceci, Yusu, Gu, Nancy D, Dalton, Kirk L, Peterson, Kun-Liang, Guan, Joan Heller, Brown, Ju, Chen, Nahum, Sonenberg, and Gianluigi, Condorelli
- Subjects
Cardiomyopathy, Dilated ,Male ,Cardiac function curve ,medicine.medical_specialty ,Cell Survival ,Apoptosis ,Cardiomegaly ,Cell Cycle Proteins ,mTORC1 ,Mechanistic Target of Rapamycin Complex 1 ,Mice ,Clinical investigation ,Internal medicine ,Eukaryotic initiation factor ,Animals ,Myocyte ,Medicine ,Initiation factor ,Myocytes, Cardiac ,Eukaryotic Initiation Factors ,Phosphorylation ,Mechanistic target of rapamycin ,PI3K/AKT/mTOR pathway ,Adaptor Proteins, Signal Transducing ,Mice, Knockout ,Pressure overload ,biology ,business.industry ,Cell growth ,Myocardium ,TOR Serine-Threonine Kinases ,Autophagy ,Proteins ,Heart ,General Medicine ,Phosphoproteins ,Cell biology ,Mice, Inbred C57BL ,Endocrinology ,Multiprotein Complexes ,Cardiology ,biology.protein ,Female ,Carrier Proteins ,Corrigendum ,business ,Transcription Factors ,Research Article - Abstract
Mechanistic target of rapamycin (MTOR) plays a critical role in the regulation of cell growth and in the response to energy state changes. Drugs inhibiting MTOR are increasingly used in antineoplastic therapies. Myocardial MTOR activity changes during hypertrophy and heart failure (HF). However, whether MTOR exerts a positive or a negative effect on myocardial function remains to be fully elucidated. Here, we show that ablation of Mtor in the adult mouse myocardium results in a fatal, dilated cardiomyopathy that is characterized by apoptosis, autophagy, altered mitochondrial structure, and accumulation of eukaryotic translation initiation factor 4E–binding protein 1 (4E-BP1). 4E-BP1 is an MTOR-containing multiprotein complex-1 (MTORC1) substrate that inhibits translation initiation. When subjected to pressure overload, Mtor-ablated mice demonstrated an impaired hypertrophic response and accelerated HF progression. When the gene encoding 4E-BP1 was ablated together with Mtor, marked improvements were observed in apoptosis, heart function, and survival. Our results demonstrate a role for the MTORC1 signaling network in the myocardial response to stress. In particular, they highlight the role of 4E-BP1 in regulating cardiomyocyte viability and in HF. Because the effects of reduced MTOR activity were mediated through increased 4E-BP1 inhibitory activity, blunting this mechanism may represent a novel therapeutic strategy for improving cardiac function in clinical HF.
- Published
- 2010
36. Expedient construction of the [5-6-7] tricyclic core of calyciphylline a-type alkaloids
- Author
-
Yun Li, Cheng Tao, Xinkan Yang, Denghong Zhang, Guangqi Yan, Hongbin Zhai, Bin Cheng, Jing-Jing Guo, and Tingting Xu
- Subjects
chemistry.chemical_classification ,chemistry ,Cyclopropanation ,Stereochemistry ,Intramolecular force ,Organic Chemistry ,Diels alder ,General Chemistry ,Biochemistry ,Cycloaddition ,Adduct ,Tricyclic - Abstract
An efficient synthetic route toward the highly congested [5-6-7] tricyclic core of calyciphylline A-type alkaloids has been developed. This approach features a highly efficient intramolecular Diels-Alder cycloaddition to establish the aza-five-membered C ring as well as the C1 all-carbon quaternary center, and a subsequent cyclopropanation together with a ring-expansion reaction of the resulted adduct to construct the seven-membered D ring.
- Published
- 2014
37. Abstract 203: Protein Synthesis Inhibitors 4E-BPs Regulate Cardiac Function
- Author
-
Denghong Zhang, Riccardo Contu, Michael Latronico, Kirk Peterson, Ju Chen, and Gianluigi Condorelli
- Subjects
Physiology ,Cardiology and Cardiovascular Medicine - Abstract
Rationale: mTOR regulates cardiac functionality and hypertrophy. We have shown that cardiac-specific deletion of mTOR induces fatal dilated cardiomyopathy. This model of heart failure is characterized biochemically by accumulation of the mTOR substrate 4E-BP1, which inhibits protein synthesis through the regulation of translation initiation. Deletion of the 4E-BP1 gene, Eif4ebp1, in mTOR-KO mice significantly, albeit partially, improved cardiac function and survival. Objective: To investigate the role of the 4E-BP family in the heart by determining whether absence of its members improves cardiac function in different models of heart failure. Methods and Results: In the absence of Eif4ebp1, cardiac expression of the 4E-BP2 homolog increases strikingly. Deletion of Eif4ebp2 along with Eif4ebp1 (4E-BP1/4E-BP2-dKO mice) abrogated the negative effects of the loss of mTOR on cardiac function, and led to a further significant improvement in survival rate. Moreover, when 4E-BP1/4E-BP2-dKO mice where subjected to pressure-overload stress, cardiac function and survival were significantly improved compared with similarly treated control mice. The hypertrophic response to pressure overload in these mice was not affected by the absence of 4E-BPs. Conclusions: Our data indicate that 4E-BPs are responsible for an important part of mTOR effects on cardiac function, further strengthening the concept that the regulation of mRNA translation profoundly affects cardiac inotropism under stress.
- Published
- 2012
38. IkappaB kinase epsilon and TANK-binding kinase 1 activate AKT by direct phosphorylation
- Author
-
Xiaoduo, Xie, Denghong, Zhang, Bin, Zhao, Min-Kan, Lu, Ming, You, Gianluigi, Condorelli, Cun-Yu, Wang, and Kun-Liang, Guan
- Subjects
Mice, Knockout ,Myocardium ,Amino Acid Motifs ,Mutation, Missense ,Fibroblasts ,Protein Serine-Threonine Kinases ,Biological Sciences ,I-kappa B Kinase ,Enzyme Activation ,Mice ,Cell Transformation, Neoplastic ,HEK293 Cells ,Rapamycin-Insensitive Companion of mTOR Protein ,Amino Acid Substitution ,Trans-Activators ,Animals ,Humans ,Naphthyridines ,Phosphorylation ,Carrier Proteins ,Proto-Oncogene Proteins c-akt ,HeLa Cells ,Transcription Factors - Abstract
AKT activation requires phosphorylation of the activation loop (T308) by 3-phosphoinositide-dependent protein kinase 1 (PDK1) and the hydrophobic motif (S473) by the mammalian target of rapamycin complex 2 (mTORC2). We recently observed that phosphorylation of the AKT hydrophobic motif was dramatically elevated, rather than decreased, in mTOR knockout heart tissues, indicating the existence of other kinase(s) contributing to AKT phosphorylation. Here we show that the atypical IκB kinase ε and TANK-binding kinase 1 (IKKε/TBK1) phosphorylate AKT on both the hydrophobic motif and the activation loop in a manner dependent on PI3K signaling. This dual phosphorylation results in a robust AKT activation in vitro. Consistently, we found that growth factors can induce AKT (S473) phosphorylation in Rictor(-/-) cells, and this effect is insensitive to mTOR inhibitor Torin1. In IKKε/TBK1 double-knockout cells, AKT activation by growth factors is compromised. We also observed that TBK1 expression is elevated in the mTOR knockout heart tissues, and that TBK1 is required for Ras-induced mouse embryonic fibroblast transformation. Our observations suggest a physiological function of IKKε/TBK1 in AKT regulation and a possible mechanism of IKKε/TBK1 in oncogenesis by activating AKT.
- Published
- 2011
39. Regioselective Coupling Reactions of Coumarins with Aldehydes or Di-tert-butyl Peroxide (DTBP) through a C(sp²)-H Functionalization Process.
- Author
-
Wannian Zhao, Lei Xu, Yingcai Ding, Ben Niu, Ping Xie, Zhaogang Bian, Denghong Zhang, and Aihua Zhou
- Subjects
COUMARINS ,ALDEHYDES ,COUPLING reactions (Chemistry) ,PEROXIDES ,CARBON-hydrogen bonds ,FUNCTIONAL groups - Abstract
Coumarin derivatives are highly valuable compounds in drug discovery. Herein, we have developed two new coupling reactions that involve coumarins and either aldehydes or di-tert-butyl peroxide (DTBP) in the presence of inexpensive copper or iron catalysts. Both of these reactions proceed through a C(sp²)-H functionalization process to regioselectivity generate keto- or methyl-substituted coumarin derivatives in moderate to good yields These coupling reactions will enrich current coumarin chemistry. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
40. Phytotoxic Allelochemicals from Roots and Root Exudates of Trifolium pratense.
- Author
-
Quan Liu, Rui Xu, Zhiqiang Yan, Hui Jin, Haiyan Cui, Liqin Lu, Denghong Zhang, and Bo Qin
- Published
- 2013
- Full Text
- View/download PDF
41. 1KB kinase ϵ and TANK-binding kinase 1 activate AKT by direct phosphorylation.
- Author
-
Xiaoduo Xie, Denghong Zhang, Bin Zhao, Min-Kan Lu, Ming You, Condorelli, Gianluigi, Cun-Yu Wang, and Kun-Liang Guan
- Subjects
- *
PROTEIN kinases , *PHOSPHORYLATION , *RAPAMYCIN , *CARCINOGENESIS , *CANCER treatment - Abstract
AKT activation requires phosphorylation of the activation loop (T308) by 3-phosphoinositide-dependent protein kinase 1 (PDK1) and the hydrophobic motif (S473) by the mammalian target of rapamycin complex 2 (mTORC2). We recently observed that phosphorylation of the AKT hydrophobic motif was dramatically elevated, rather than decreased, in mTOR knockout heart tissues, indicating the existence of other kinase(s) contributing to AKT phosphorylation. Here we show that the atypical IκB kinase ϵ and TANK-binding kinase 1 (IKKϵ/TBK1) phosphorylate AKT on both the hydrophobic motif and the activation loop in a manner dependent on PI3K signaling. This dual phosphorylation results in a robust AKT activation in vitro. Consistently, we found that growth factors can induce AKT (S473) phosphorylation in Rictor-/- cells, and this effect is insensitive to mTOR inhibitor Torini. In IKKϵ/TBK1 double-knock-out cells, AKT activation by growth factors is compromised. We also observed that TBK1 expression is elevated in the mTOR knockout heart tissues, and that TBK1 is required for Ras-induced mouse embryonic fibroblast transformation. Our observations suggest a physiological function of IKKϵ/TBK1 in AKT regulation and a possible mechanism of IKKϵ/TBK1 in oncogenesis by activating AKT. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
42. Effects of electron correlation and the Breit interaction on one- and two-electron one-photon transitions in double K hole states of He-like ions (10 ≤ Z ≤ 47).
- Author
-
Xiaobin Ding, Cunqiang Wu, Mingxin Cao, Denghong Zhang, Mingwu Zhang, Yingli Xue, Deyang Yu, and Chenzhong Dong
- Subjects
ELECTRON configuration ,RADIATIVE transitions ,IONS ,ELECTRON transitions ,ENERGY level transitions - Abstract
The x-ray energies and transition rates associated with single and double electron radiative transitions from the double K hole state 2s2p to the 1s2s and 1s
2 configurations of 11 selected He-like ions (10 ≤ Z ≤ 47) are calculated using the fully relativistic multi-configuration Dirac–Fock method (MCDF). An appropriate electron correlation model is constructed with the aid of the active space method, which allows the electron correlation effects to be studied efficiently. The contributions of the electron correlation and the Breit interaction to the transition properties are analyzed in detail. It is found that the two-electron one-photon (TEOP) transition is correlation sensitive. The Breit interaction and electron correlation both contribute significantly to the radiative transition properties of the double K hole state of the He-like ions. Good agreement between the present calculation and previous work is achieved. The calculated data will be helpful to future investigations on double K hole decay processes of He-like ions. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
43. Electron-impact single ionizaiton for W4+ and W5+.
- Author
-
Denghong Zhang, Luyou Xie, Jun Jiang, Zhongwen Wu, Chenzhong Dong, Yinglong Shi, and Yizhi Qu
- Subjects
- *
ELECTRON impact ionization , *TUNGSTEN , *IONIZATION cross sections , *BRANCHING ratios , *AUGER effect - Abstract
Electron-impact single ionization cross sections for Wq+ (q = 4–5) were calculated using the flexible atomic code (FAC) in the level-to-level distorted-wave method, considering the explicit branching ratio. The calculated cross sections are compared with the available theoretical and experiment results in detail. In the case of the contribution from the same channles as the available theoretical results, all of the calculated ionization cross sections agree with the experimental measured cross sections. But the present calculated results are larger than the experimental measurement when all channels contributions are included. Some important channels excitation autoionization (EA) contributions, such as the excitation to higher higher subshell from 4f and 5[s,p], were not included into the available theoretical calculation. In general, the distorted-wave (DW) results are overestimated. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
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