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Pushing the boundaries of c-H bond functionalization chemistry using flow technology

JOURNAL OF FLOW cHEMISTRY 2020年第1期10卷 13-71页

作者： Govaerts, Sebastian Nyuchev, Alexander Noel, Timothy Eindhoven Univ Technol Dept Chem Engn & Chem Micro Flow Chem & Synthet Methodol Den Dolech 2 NL-5612 AZ Eindhoven Netherlands Univ Manchester Sch Chem Oxford Rd Manchester M13 9PL Lancs England

c-H functionalization chemistry is one of the most vibrant research areas within synthetic organic chemistry. While most researchers focus on the development of small-scale batch-type transformations, more recently such transformations have been carried out in flow reactors to explore new chemical space, to boost reactivity or to enable scalability of this important reaction class. Herein, an up-to-date overview of c-H bond functionalization reactions carried out in continuous-flow microreactors is presented. A comprehensive overview of reactions which establish the formal conversion of a c-H bond into carbon-carbon or carbon-heteroatom bonds is provided;this includes metal-assisted c-H bond cleavages, hydrogen atom transfer reactions and c-H bond functionalizations which involve an S-E-type process to aromatic or olefinic systems. Particular focus is devoted to showcase the advantages of flow processing to enhance c-H bond functionalization chemistry. consequently, it is our hope that this review will serve as a guide to inspire researchers to push the boundaries of c-H functionalization chemistry using flow technology.

关键词： cross coupling c H activation catalysis Microreactor Flow chemistry

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适用于新型环保绝缘混合气体c4F7N/N2的露点检测研究

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上海电力大学学报 2025年

作者：杨昊欣赵文彬李峰上海电力大学电气工程学院

目前常用的露点测试设备大多只适配SF6气体，对新型环保绝缘混合气体的测量误差较大，且国内外关于c4F7N混合气体的露点检测研究较少。因此，基于镜面式露点测量原理，提出了一种气体露点的新型测量方法。首先，搭建了实验平台得到SF6... 详细信息

目前常用的露点测试设备大多只适配SF6气体，对新型环保绝缘混合气体的测量误差较大，且国内外关于c4F7N混合气体的露点检测研究较少。因此，基于镜面式露点测量原理，提出了一种气体露点的新型测量方法。首先，搭建了实验平台得到SF6气体的露点特性，验证了实验的可行性；然后，通过理论计算得出c4F7N气体及混合气体的饱和蒸气压曲线，得到不同条件下c4F7N气体以及c4F7N/N2混合气体的露点变化情况；最后，利用相对绝缘强度量化分析了c4F7N/N2混合气体与纯SF6气体的绝缘特性差异，研究了c4F7N/N2混合气体的绝缘性能及其应用的可行性。结果表明，c4F7N/N2混合气体露点与气压呈正相关关系，与c4F7N所占摩尔分数也呈正相关关系。在户外最低工作环境温度（258 K）条件下，当气室气压为0.4 MPa时，建议c4F7N/N2混合气体中c4F7N所占摩尔体积在19.51%～29.29%；当气室气压为0.6 MPa时，c4F7N所占摩尔体积为19.69%的c4F7N/N2混合气体满足工程使用需求，可实现同等条件下对纯SF6气体的替换。

关键词： c F N/N 混合气体饱和蒸气压露点温度微水

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Endothelial Nitric Oxide Synthase Gene Polymorphisms (-922A > G,-786 T > c, Intron 4 b/a VNTR and 894 G > T) and Essential Hypertension: An Association Study with Haplotypes Analysis

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BIOcHEMIcAL GENETIcS 2020年第4期58卷 518-532页

作者： Farbood, Zahra Aghabozorgi, Amirsaeed Sabeti Nejatizadeh, Azim Farshidi, Hossein Shams, Leila Bahreyni, Amirhossein Babamansouri, Elahe Mansouri Shekari, Mohammad Hormozgan Univ Med Sci Mol Med Res Ctr Bandar Abbas Iran Hormozgan Univ Med Sci Hormozgan Cardiovasc Res Ctr Bandar Abbas Iran St Pauls Hosp Ctr Heart Lung Innovat Vancouver BC Canada Univ British Columbia Dept Pathol & Lab Med Vancouver BC Canada

Endothelial Nitric Oxide Synthase (eNOS) is an indispensable regulator of blood pressure through producing Nitric Oxide (NO). There is some evidence to suggest thateNOSgene polymorphisms are associated with Essential Hypertension (EHT). In this study, the potential association betweeneNOS4a/4b, A922G, G894T, T786c gene polymorphisms and EHT as individual risk factors and as haplotypes are examined in the southern population of Iran (Bandar-Abbas). In this study, 200 EHT patients and 200 normotensive subjects which were matched for age and sex were included. Genotyping was performed by either utilizing Polymerase chain Reaction (PcR) or PcR followed by Restriction Fragment length Polymorphism (RFLP) method. Our results demonstrated statistically significant associations between T786c, G894T, and 4a/4a and EHT (p < 0.05);however, A922G had no significant association with EHT (p > 0.05). Haplotype analysis also suggested that - 786c/- 922A/4a, - 786c/- 922A/4b and - 786c/- 922G/4a haplotypes were more frequent in EHT group than control group, hypothesizing a positive association with EHT. The present study has identified that the eNOS genetic variations are associated with EHT in southern population of Iran (Bandar-Abbas). These findings also suggested that a number of haplotypes ofeNOSgene may be a driving factor for EHT susceptibility in respected population.

关键词： eNOSpolymorphism -922A G -786 t c Intron 4 b a VNTR 894 g t Haplotype Essential hypertension

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Indole-3-carbaldehydes Arylhydrazones as Multisite c-Nucleophiles in the Reactions with Quinazoline

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RUSSIAN JOURNAL OF GENERAL cHEMISTRY 2020年第9期90卷 1601-1610页

作者： Azev, Yu. A. Koptyaeva, O. S. Eltsov, O. S. Yakovleva, Yu. A. Tsmokalyuk, A. N. Ivoilova, A. V. Seliverstova, E. A. Pospelova, T. A. Bakulev, V. A. Ural Fed Univ Ekaterinburg 620002 Russia

c,c-coupling of indole-3-carbaldehyde arylhydrazones with quinazoline in trifluoroacetic acid has occurred at position 5 or 7 ' of the hydrazone molecule and has afforded the sigma-adducts. The c,c-coupling has been accompanied by a change in theE-configuration of the c=N bond of the starting hydrazones to theZ-configuration in the formed quinazoline trifluoroacetyl hydrazides.

关键词： arylhydrazones indole-3-carbaldehydes c c-coupling quinazoline trifluoro hydrazides

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Redescription and molecular characterization of crenidens macracanthus Gunther, 1874 (Pisces: Sparidae), and first record of c. indicus Day, 1873 in the eastern Indian Ocean

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JOURNAL OF THE MARINE BIOLOGIcAL ASSOcIATION OF THE UNITED KINGDOM 2020年第7期100卷 1147-1153页

作者： Roul, Subal Kumar Jeena, N. S. Ghosh, Shubhadeep Rohit, Prathibha ICAR Cent Marine Fisheries Res Inst Puri Field Ctr Puri 752002 Odisha India ICAR Cent Marine Fisheries Res Inst PB 1603Ernakulam North PO Cochin 682018 Kerala India ICAR Cent Marine Fisheries Res Inst Visakhapatnam Reg Ctr Visakhapatnam 530003 Andhra Pradesh India ICAR Cent Marine Fisheries Res Inst Mangalore Res Ctr Mangaluru 575001 Karnataka India

crenidens macracanthus was originally described in 1874 based on a single specimen collected from chennai (Madras), south-east coast of India. In 1875, the species was synonymized with c. indicus without citing any valid reason. Since then, no taxonomic studies have been attempted for the genus crenidens, except in 2013 the species was resurrected from synonymy and redescribed as a valid species based on the holotype and non-type specimen. In view of the fact that c. macracanthus is a poorly known species, it is redescribed based on examination of 30 additional specimens of 105.8-162.2 mm SL, collected from Puri, Odisha, north-east coast of India (Bay of Bengal) from 2017-2019, using morphological and molecular examinations. Our study provides a detailed morphological description, first colour photographs and phylogenetic analysis using cOI barcodes of the species. The study has expanded the range in several morpho-meristic characters in comparison with the type and non-type specimens described earlier. The species in fresh condition can be easily distinguished from its two congeners (c. crenidens and c. indicus) by the yellowish tip of the lower caudal-fin lobe. Our study has also extended the distribution range of c. indicus (previously known only from the north-eastern Arabian Sea) to the eastern Indian Ocean, based on examination of a preserved specimen collected from Tuticorin, Tamil Nadu.

关键词： crenidens macracanthus c indicus Sparidae redescription cOI barcode Indian Ocean

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Boosting the apoptotic response of high-grade serous ovarian cancers withccNE1amplification to paclitaxelin vitroby targeting APc/c and the pro-survival protein McL-1

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INTERNATIONAL JOURNAL OF cANcER 2020年第4期146卷 1086-1098页

作者： Raab, Monika Kobayashi, Nene F. Becker, Sven Kurunci-csacsko, Elisabeth Kraemer, Andrea Strebhardt, Klaus Sanhaji, Mourad Goethe Univ Dept Gynecol Theodor Stern Kai 7 D-60590 Frankfurt Germany German Canc Res Ctr German Canc Consortium DKTK Heidelberg Germany

Ovarian cancer exhibits the highest mortality rate among gynecological malignancies. Antimitotic agents, such as paclitaxel, are frontline drugs for the treatment of ovarian cancer. They inhibit microtubule dynamics and their efficiency relies on a prolonged mitotic arrest and the strong activation of the spindle assembly checkpoint (SAc). Although ovarian cancers respond well to paclitaxel, the clinical efficacy is limited due to an early onset of drug resistance, which may rely on a compromised mitosis exit associated with weakend intrinsic apoptosis. Accordingly, we aimed at overcoming SAc silencing that occurs rapidly during paclitaxel-induced mitotic arrest. To do this, we used a specific anaphase-promoting complex/cyclosome (APc/c) inhibitor to prevent a premature mitotic exit upon paclitaxel treatment. Furthermore, we investigated the role of the antiapoptotic BcL-2 family member McL-1 in determining the fate of ovarian cancer cells lines withccNE1amplification that are challenged with clinically relevant dose of paclitaxel. Using time-laps microscopy, we demonstrated that APc/c and McL-1 inhibition under paclitaxel prevents mitotic slippage in ovarian cancer cell lines and restores death in mitosis. consistent with this, the combinatorial treatment reduced the survival of ovarian cancer cells in 2D and 3D cell models. Since a therapeutic ceiling has been reached with taxanes, it is of utmost importance to develop alternative strategies to improve the patient's survival. Thus, our study provides not only elements to understand the causes of taxane resistance inccNE1-amplified ovarian cancers but also suggests a new combinatorial strategy that may improve paclitaxel-based efficacy in this highly lethal gynecological disease.

关键词： high grade serous ovarian cancer ccNE1amplification paclitaxel combination therapy spindle assembly checkpoint APc c McL-1 APc c inhibitor proTAME McL-1 inhibitor A1210477 mitotic slippage apoptosis

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Damage Assessment of 2.5D c/Sic ceramic Matrix composite: Effect of Fibre Off-Axis Orientation

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TRANSAcTIONS OF THE INDIAN INSTITUTE OF METALS 2020年第4期73卷 999-1006页

作者： Patel, Manish Kumar, Jalaj Kiran, Phani S. Jayakumar, T. Kumar, Vikas Prasad, V. V. Bhanu Def Met Res Lab Hyderabad 500058 India

2.5D c/Sic ceramic matrix composite is widely used for thermal protection and hot sections of gas turbine engines. The fibre axis in these components plays a big role in its performance, under multi-axial strain conditions. In the present investigation, the effect of fibre orientations has been studied. Three-point bend specimens of this composite with 30 degrees/- 60 degrees, 45 degrees/- 45 degrees and 0 degrees/90 degrees fibre orientations have been prepared and tested under bending loads. Various mechanical parameters such as flexural strength and Young's modulus have been evaluated. A considerable reduction in the flexural strength and Young's modulus has been observed in this composite with 30 degrees/- 60 degrees and 45 degrees/- 45 degrees fibre off-axis orientations. In situ damage assessment has been conducted with the help of the acoustic emission technique. Various micro-mechanics parameters such as the matrix cracking stress, matrix cracking saturation stress and stress for fibre fracture initiation have been derived using acoustic emission data as a function of the off-axis orientation of the fibres.

关键词： c Sic ceramic matrix composite Off-axis orientation Damage assessment

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Seroprevalence and risk factors of Q-fever (c. burnetii infection) among ruminants reared in the eastern region of the Kingdom of Saudi Arabia

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TROPIcAL ANIMAL HEALTH AND PRODUcTION 2020年第5期52卷 2631-2638页

作者： Aljafar, Abdullah Salem, Mohammed Housawi, Fadhel Zaghawa, Ahmed Hegazy, Yamen King Faisal Univ Coll Vet Med Dept Clin Studies Al Hasa Saudi Arabia King Faisal Univ Vet Teaching Hosp Coll Vet Med Al Hasa Saudi Arabia Cairo Univ Fac Vet Med Dept Med & Infect Dis Cairo Egypt Univ Sadat City Fac Vet Med Dept Anim Med & Infect Dis Sadat City Egypt Univ Kafrelsheikh Fac Vet Med Dept Anim Med Kafr Al Sheikh Egypt

Q-fever is a worldwide spread zoonotic disease associated with severe illness in humans and abortions and stillbirths in ruminants. Ruminants are major sources of human infection where subclinical carriers shed the bacteria in various secretions and excreta. The goal of the current study was to investigate the prevalence and risk factors of coxiella burnetii infection among cattle, sheep, and goats in the eastern province of the Kingdom of Saudi Arabia (KSA). A total of 1310 serum samples were collected through a designed cross-sectional study from private farms and slaughterhouses in the study area and examined against antibodies of c. burnetii using ELISA. A multivariate logistic regression analysis was built to detect risk factors of c. burnetii infection among examined species. The prevalence of c. burnetii infection among examined animals was 9.2% (cI, 7.7-10.8)-15.6%, 9.1%, and 5.8% among goats, cattle, and sheep, respectively). The risk of getting c. burnetii infection among old animals (> 1 year old) was 23 times higher than the risk among young animals (< 1 year old) (95% cI, 10.04-53.01;P < 0.01). Goats were 2.27 (95% cI, 1.41-3.66;P < 0.01) and 3 times at higher risk than cattle and sheep, respectively, of getting c. burnetii infection. In conclusion, c. burnetii infection is widespread among different ruminant species of the eastern province of KSA which represents a high risk for environmental contamination and disseminating the infection to humans and animal species in that area. Also, our findings may reflect the disease status in other countries of the Arabian Gulf area.

关键词： Q-fever c burnetii Prevalence risk factors Saudi Arabia

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Shifts in Microbial Biomass c/N/P Stoichiometry and Bacterial community composition in Subtropical Estuarine Tidal Marshes Along a Gradient of Freshwater-Oligohaline Water

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EcOSYSTEMS 2020年第6期23卷 1265-1280页

作者： Hu, Minjie Penuelas, Josep Sardans, Jordi Yang, Xianyu Tong, chuan Zou, Shuangquan cao, Wenzhi Xiamen Univ Coll Environm & Ecol State Key Lab Marine Environm Sci Xiangan South Rd Xiamen 361102 Fujian Peoples R China Global Ecol CREAF CSIC UAB CSIC Barcelona 08193 Catalonia Spain CREAF Barcelona 08193 Spain East China Normal Univ Sch Ecol & Environm Sci Shanghai 200241 Peoples R China Fujian Normal Univ Key Lab Humid Subtrop Ecogeog Proc Minist Educ Fuzhou 350007 Fujian Peoples R China Fujian Agr & Forestry Univ Coll Forestry Fuzhou 350002 Fujian Peoples R China

Saltwater intrusion results in increased estuarine salinity, affecting both ecosystem nutrient dynamics and bacterial community composition in estuarine tidal marshes. However, whether soil microbial biomass (SMB) and bacterial community composition have different responses to low levels of salinity increase is largely unknown. We designed an experiment to investigate the stoichiometry of microbial biomass and bacterial community composition in both the rhizospheres and bulk soils along a low-level salinity gradient across two freshwater and three oligohaline marshes. Soil microbial biomass c (MBc) and microbial biomass nitrogen (MBN) significantly decreased in both rhizospheres and bulk soils as salinity increased, while microbial biomass phosphorus (MBP) increased only in the rhizospheres. Rhizospheric effects increased the concentrations of MBc and MBP but did not significantly affect the concentration of MBN relative to the bulk soils. MBc/MBN/MBP ratios fluctuated drastically, and no clear trends were observed for both the rhizospheres and bulk soils along the salinity gradient. The composition of the bacterial communities changed greatly with increases in salinity, affected by changes in the proportional frequencies of the bacterial taxa, while bacterial alpha diversity was not significantly affected by salinity. A redundancy analysis found that the overlying water salinity and sulfate and soil total organic carbon had a synergistic effect on SMB and bacterial community composition. Our findings demonstrate that increased salinity, even in the low-level salinity range, had a large effect on decreasing MBc and MBN pools, increasing MBP stocks, and affecting bacterial community composition. However, it had a small effect on bacterial diversity. Also, rhizospheres exerted a major control on increasing MBc and MBP but rarely affected bacterial community composition or diversity.

关键词： Microbial biomass c N P stoichiometry Bacterial community Salinity Estuarine tidal marsh

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cDK2 destabilizes tumor suppressor c/EBPα expression through ubiquitin-mediated proteasome degradation in acute myeloid leukemia

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JOURNAL OF cELLULAR BIOcHEMISTRY 2020年第4期121卷 2839-2850页

作者： Thacker, Gatha Mishra, Mukul Sharma, Akshay Singh, Anil Kumar Sanyal, Sabyasachi Trivedi, Arun Kumar Cent Drug Res Inst CSIR Div Canc Biol Room LSS008Sect 10 Lucknow 226031 Uttar Pradesh India CDRI CSIR AcSIR Lucknow Uttar Pradesh India

Deregulation and functional inhibition of ccAAT-enhancer-binding protein alpha (c/EBP alpha), a key transcription factor of myeloid lineage leads to development of myeloid leukemia. In this study, we show that cyclin-dependent kinase 2 (cDK2) negatively regulates c/EBP alpha protein levels in myeloid leukemia cells. The overexpression of cDK2 inhibited c/EBP alpha both in a heterologous HEK293T and U937 myeloid leukemia cells. On the contrary, cDK2 depletion enhanced endogenous c/EBP alpha protein levels. cDK2 mitigated c/EBP alpha levels by promoting its ubiquitin-mediated proteasome degradation. We further showed that although cDK2 interacted with c/EBP alpha, direct interaction of cDK2 with c/EBP alpha is not involved in c/EBP alpha downregulation. cDK2-dependent phosphorylation of c/EBP alpha on its widely reported phosphorylatable amino acid residues is apparently not required for c/EBP alpha degradation by cDK2. Furthermore, our data demonstrate that cDK2-driven c/EBP alpha inhibition mitigates its transactivation potential and cellular functions such as ability to promote myeloid differentiation and growth arrest.

关键词： acute myeloid leukemia c EBP alpha cDK2 myeloid differentiation ubiquitination

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