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Naturally acquired HPV antibodies against subsequent homotypic infection: A large-scale prospective cohort study
No full text宫颈癌是全球15-44岁女性中第二常见的癌症，其主要病因是高危型HPV的感染，尤其是HPV 16型和18型的感染，在我国与约84%的宫颈癌有关。早期研究显示因自然免疫获得抗体的女性再次感染同型HPV的风险降低较为有限（约35%），但在这些研究中多依据IgG抗体而非中和抗体作为自然免疫指标进行保护效果分析。我校研究人员利用国产双价HPV疫苗III期临床试验中未接种HPV疫苗且HPV DNA为阴性的3600余名18-45岁健康女性队列，分别采用中和抗体和IgG抗体作为获得自然免疫的指标，分析其在之后5.5年的随访期间再次感染同型HPV的风险。该研究首次在大样本长期随访队列中以中和抗体作为免疫指标评价HPV自然免疫效果，获得了客观准确的HPV自然免疫数据，丰富了HPV自然史研究，为HPV疫苗接种策略的制订提供了重要依据。我校博士生姚星妹、中国医学科学院肿瘤医院陈汶教授和北京大学人民医院赵超教授为该论文共同第一作者。我校吴婷教授、张军教授、夏宁邵教授和中国医学科学院肿瘤医院乔友林教授、赵方辉教授为该论文的共同通讯作者。Background: Although recent studies have suggested that naturally acquired Human papillomavirus (HPV)
antibodies are partly protective against subsequent homotypic infection, the extent of protection remains
indecisive. Here, we evaluate the protective effect of neutralizing and IgG antibodies simultaneously.
Methods: In a cohort of 3634 women aged 18-45 years from the control arm of a phase III trial of the
HPV-16/18 bivalent vaccine, participants were tested for neutralizing antibodies by pseudovirion-based
neutralization assay (PBNA) and IgG antibodies by enzyme-linked immunosorbent assay (ELISA) at baseline. HPV-16/18 incident and persistent infections were identified using cervical specimens periodically
collected during the 5.5 years of follow-up. The protective effects of HPV-16/18 neutralizing and IgG antibodies against homotypic infection were assessed using a Cox proportional hazard model.
Findings: For the persistent infection (PI) endpoints of HPV-16/18 lasting for over 6/12 months, a prevalence of type-specific neutralizing antibodies was highly protective (6-month PI: hazard ratio (HR) = 0.16,95% confidence interval (CI): 0.04, 0.65; 12-month PI: HR = 0.23, 95% CI: 0.06, 0.94), whereas a prevalence of IgG antibodies was associated with minor and non-significant protection (6-month PI: HR = 0.66,
95% CI: 0.40, 1.09; 12-month PI: HR = 0.66, 95% CI: 0.36, 1.20). After increasing the cut-off value to the
median IgG level, the risk of 6-month PI was significantly lower in seropositive vs seronegative women
(HR = 0.38, 95% CI: 0.18, 0.83).
Interpretation: Naturally acquired antibodies are associated with a substantially reduced risk of subsequent homotypic infection.We thank all the study participants and research staff of the HPV-003 Study Group for their contributions to the present study. In addition, we also thank Dr. Allan Hildesheim of the Division of Cancer Epidemiology and Genetics at the National Cancer Institute, National Institutes of Health for his helpful comments on this study.该研究获得国家自然科学基金、福建省卫生教育联合攻关计划项目、厦门市科技重大专项、中国医学科学院医学科学创新基金和厦门万泰沧海生物技术有限公司的支持。Funding: NSFC; The Fujian Province Health Education Joint Research Project; Xiamen Science and Technology Major Project; CIFMS; and Xiamen Innovax
Mathematical Expression and Quantitative Analysis of Impedance Spectrum on the Interface of Glassy Carbon Electrode
No full text玻碳电极（GCE）是各类电化学传感器常用的基础电极,其界面特征直接影响检测性能。本文详细考察了电极体系的电化学过程,针对GCE传感界面,探讨了一个等效电路中电解质电阻、电荷输运电阻、扩散阻抗、电化学（氧化/还原）反应阻抗、表面吸附阻抗和双电层电容等电学元件的物理意义,并给出了对应的数学模型。通过改变模型中5个参数值,模拟了不同状态下的阻抗谱,分析了电极系统各参数对GCE阻抗谱的贡献规律。最后,采用该数学模型对裸GCE和修饰GCE在铁氰化钾溶液中的阻抗谱进行分析,拟合结果与实验数据吻合度高;基于拟合获得参数,定量对比分析了修饰前后电极表面的特征变化。Glassy carbon electrode (GCE) is a common basic electrode for various electrochemical sensors, and the detection properties are determined by its interfacial characteristics. In this paper, we established an equivalent circuit including electrolyte resistance (Rel), charge transport resistance (Rct), diffusion impedance (Rdi, Cdi), electrochemical (oxidation/reduction) reaction impedance (RR, CR), surface adsorption impedance (Rads , Cads), double-layer capacitance (CDL), and derived the mathematical expression for the equivalent circuit. The Rel and CDL are contributed by inactive ions in electrolyte to produce non-faradaic impedance, while the Rct and RR are contributed by the active ions of redox reaction in electrolyte to produce faradaic impedance. The Rct directly corresponds to the electrode potential (E) of the reaction, which represents the difficulty of electrode reaction. When the potential E is the only state variable in the impedance spectrum of electrode reaction, that is, there is only one time constant in the impedance spectrum, the Rct can represent the whole Faraday impedance of the system. However, when the electrode reaction is also affected by other variables such as diffusion, surface film or surface adsorption ion coverage, the Faraday impedance of the system also includes the impedance produced by the diffusion impedance and the changes of the surface film (RR, CR) and the coverage of the surface absorbed ions caused by electrochemical reaction (Rads, Cads). The impedance spectrum of the electrode system in different states were simulated by changing the five parameters of the mathematical expression. The contribution of different factors to the impedance spectrum of GCE was revealed. Finally, the impedance spectra of bare/modified GCE in potassium ferricyanide solution were analyzed by the mathematical model. The fitting results are in good agreement with the experimental data. Based on the parameters obtained by fitting, the changes of the electrode surface characteristic before and after modifications were quantitatively compared and analyzed. The charge transport resistance increases from 5827.8 Ω to 25104.3 Ω, and the diffusion conductance of Fe3+/Fe2+ ions on the electrode surface also increases by an order of magnitude. However, there is no significant difference with the double-layer capacitance and the frequency dispersion coefficient. The surface of the modified electrode remains electrically neutral. The aggregation state and oxidation-reduction mechanism of Fe3+/Fe2+ on the electrode surface are the same as those on the bare GCE surface.国家自然科学基金重点项目(21431001);广西自然科学基金(2020GXNSFBA297001)通讯作者:程蕾E-mail:[email protected]:LeiChengE-mail:[email protected]广西师范大学化学与药学学院,省部共建药用资源化学与药物分子工程国家重点实验室,广西 桂林 541004State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmaceutical Science, Guangxi Normal University, Guilin 541004, Guangxi, Chin
Effect of Alkyl Chain Length of Symmetrical Quaternary Ammonium Hydroxide on Oxalic Acid Electroreduction Reaction
No full text研究了四种不同烷基链长度的对称季铵碱对草酸电还原制备乙醛酸反应的影响。线性扫描测试考察了添加剂对铅电极上阴极反应的影响,结果表明对称季铵碱在电极表面的吸附对析氢反应的抑制程度大于其对草酸电还原反应的抑制程度,且随着对称季铵碱中烷基链长度的增加,添加剂抑制析氢反应效果更明显。计时安培法的结果证明添加剂可影响草酸向电极表面的扩散,随着对称季铵碱中烷基链长度的增加,草酸的扩散系数呈现出先增加后减小的趋势。恒流电解实验结果表明,添加剂能有效提高草酸电还原反应的电流效率,且提高效果随对称季铵碱所含烷基链长度的增加而增强。因此,添加剂的吸附对阴极表面析氢反应的抑制作用是草酸电还原反应电流效率提高的主要原因。本研究表明,四丁基氢氧化铵为添加剂时,草酸还原为乙醛酸的电流效率最高。Glyoxylic acid with the dual characteristics of acid and aldehyde is an important chemical raw material and organic synthesis intermediate, which is extensively used in the perfumery, pharmaceutical and fine chemical industries. A family of symmetric quaternary ammonium hydroxides (QAHs) with different alkyl chain lengths was used as the additives in generating glyoxylic acid from oxalic acid electroreduction reaction (OAER). The effects of alkyl chain length on OAER and the corresponding side reaction, i.e., hydrogen evolution reaction (HER), were investigated. Linear sweep voltammetric (LSV) results showed that the adsorption of the additives suppressed more on the HER than that on OAER, resulted in improving the current efficiency of OAER. As the alkyl chain length of QAH increased, the suppression effect on HER was more obvious. The effect of additives on oxalic acid diffusion was studied by chronoamperometry (CA). With the increase in the alkyl chain length of the QAH additives, the diffusion coefficient of oxalic acid increased first and then decreased. The constant-current electrolysis results showed that the additives could effectively improve the current efficiency of the OAER, which was highly related to the alkyl chain length of QAHs. The LSV, CA and electrolysis results indicate that the suppression effect of QAHs adsorption on HER is the main reason for the improvement of current efficiency. In this study, tetrabutylammonium hydroxide (TBAH) is the best additive to increase the current efficiency of generating glyoxylic acid from oxalic acid.通讯作者:胡硕真E-mail:[email protected]:Shuo-ZhenHuE-mail:[email protected]华东理工大学化学工程联合国家重点实验室,上海 200237State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, P.R. Chin
Numerical Study on the Influences of Flow Channel and Rib Width Ratio on the Performance of Gas Diffusion Layer
No full text由于装配压力的作用,气体扩散层产生形变,对质子交换膜燃料电池性能产生影响。国内外学者主要研究气体扩散层形变后对燃料电池性能产生的影响,但对不同流道宽度的燃料电池探究尚不明确。本文采用有限元法建立一个单流道质子交换膜燃料电池三维模型,研究了不同装配压力以及三种流道与肋度比(流道与肋宽比分别为3:2、1:1、2:3)下,气体扩散层厚度变化规律以及它们对孔隙率和电导率的影响。结果显示,随着装配压力的增加,肋下气体扩散层厚度变薄,孔隙率减小,电导率增加;在相同装配压力下,流道与肋宽度比值越大,肋下孔隙率越小,电导率越大。Proton exchange membrane fuel cell (PEMFC) has the advantages of low noise, high power density, and zero emission. It is widely used in ships, automobiles, aviation and other fields. PEMFC is composed of bipolar plate (BP), gas diffusion layer (GDL), catalytic layer (CL) and proton exchange membrane (PEM). GDL has a supporting catalytic layer and proton exchange membrane, which provides gas diffusion for the reaction and a channel for the reaction to produce water, and transmits the anodic oxidation reaction. In the assembly of fuel cells, a certain assembly pressure is required to ensure air-tightness and effective conductivity. The assembly pressure will cause the GDL deformation and the loss of hydrophobic materials; however, the assembly pressure can improve the durability of the battery. Too small assembly pressure will lead to insufficient battery sealing, high contact resistance and other undesirable results. Larger assembly pressure can improve the hydrogen utilization rate and ensure the stable operation of the battery as the assembly pressure increases, Liquid water accumulates more; excessive assembly pressure leads to reduced porosity and lower reaction rate, and even damage of membrane electrode assembly (MEA). Therefore, there is an optimal assembly pressure to obtain lower contact resistance when compressing GDL. At the same time, it has a relatively high porosity. Scholars at home and abroad have mainly studied the effect of GDL deformation on the battery performance, but the exploration of fuel cells with different flow channel widths is not clear. This paper uses the finite element method to establish a single flow. Three-dimensional model of the PEMFC channel has been studied, and the GDL thickness changes and their impacts on the pores under different assembly pressures and three kinds of flow channel to rib ratios (the channel and rib width ratios of 3:2, 1:1, 2:3) were investigated. The results show that: (1) GDL deformation increased with the increases of the ratio of flow channel to rib width and assembly pressure, but the rate of change gradually slowed down. (2) Under the ribs,the porosity of GDL decreased with the increase of assembly pressure, and the decreased change rate continued to be accelerated; under the same assembly pressure, the greater the ratio of channel to rib width, the more significant the porosity change. (3) Conductivity increased with the increase of assembly pressure, and the rate of change was also accelerated with the increase of assembly pressure; under the same assembly pressure, the greater the ratio of the flow channel to the rib width, the greater the electrical conductivity. When the ratio of channel to rib width was 3:2, there was an intersection point at 1.5 ~ 2.0 MPa. According to the balanced relationship between porosity and conductivity, the optimal assembly pressure may be in this interval, which needs to be further verified.国家自然科学基金(51779025);国家自然科学基金(52001045);中国博士后基金(2019M651097);中国博士后基金(2019M651094);辽宁省自然科学基金(2019-BS-026);辽宁省自然科学基金(2020-HYLH-38)通讯作者:李世安E-mail:[email protected]:Shi-AnLiE-mail:[email protected].大连海事大学轮机工程学院,辽宁 大连 1160262.大连海事大学新能源船舶动力技术研究院,辽宁 大连 1160261. School of Marine Engineering, Dalian Maritime University, Dalian 116026, Liaoning, China2. The Institute of New Energy Technologies for Ship Power System, Dalian Maritime University,Dalian 116026, Liaoning, Chin
Performance and Mechanism of PtxCuy/C Electrocatalyst for Methanol Oxidation
No full text直接甲醇燃料电池（DMFC）是一种将甲醇燃料的化学能直接转化为电能的能量转换装置,具有能量转化效率高、环境友好、燃料来源丰富等优势,在移动电源等领域具有广泛应用前景,但阳极铂基电催化剂的性能及成本制约着DMFC的发展。本论文通过简单的液相浸渍还原法,制备了系列PtCu/C纳米电催化剂,电化学性能测试结果表明,电催化剂对甲醇氧化反应（MOR）活性顺序为商品Pt/C < Pt3Cu/C < PtCu4/C < PtCu/C < PtCu3/C,且活性最高的PtCu3/C电催化剂表现出较为优异的电化学稳定性。结合物相表征、电化学测试及DFT计算,阐释了PtCu3/C催化剂中存在的少量CuO相能够促进水分子解离产生*OH,通过双功能机制促进类CO反应中间物种氧化为CO2。因此,相比于商品Pt/C,虽然PtCu3/C电催化剂的ECSA不足其一半,但质量比活性和面积比活性分别提高1.88倍和3.74倍。Direct methanol fuel cell (DMFC), which directly converts the chemical energy of methanol fuel into electrical energy, has the advantages of high energy conversion efficiency, environmental friendliness, and abundance of fuel sources. DMFC is considered as the promising substitutes in the field of portable devices, military applications, and stationary power stations, while the broad application is severely hindered by the sluggish kinetic of methanol oxidation reaction (MOR) in the anode and the high cost of platinum (Pt)-based anodic electrocatalysts. Herein, a series of carbon supported PtxCuy (PtxCuy/C) binary metal electrocatalysts, featured with high activity and low consumption of precious metal, were prepared under the ambient environment by a simple liquid phase impregnation reduction method using ethanol as the solvent and sodium borohydride as the reducing agent. Uniform distribution of PtxCuy nanoparticles in the range of 2 ~ 4 nm was achieved by rationally optimizing the dropping rate, stoichiometric ratio, and reaction time. As revealed by XRD and TEM characterizations, adding way of the reducing agent into the metal salt precursor carbon slurry had a significant impact on the morphology. Compared with dumping, adding the reducing agent in a dropwise way was beneficial for obtaining nanoparticles with a smaller size and uniform distribution. By adjusting the amount of the reducing agent up to 20 times the molar amount of metal precursors, the complete reduction, signifying a higher loading and less waste of Pt precursors, can be safely ensured. When increasing the content of Cu precursors, those metal nanoparticles tended to connect into worm-like structures and the individual CuO phase was observed in PtCu3/C and PtCu4/C samples. MOR activity of as-prepared electrocatalysts was determined by systematically electrochemical measurements and an activity order of commercial Pt/C < Pt3Cu/C < PtCu4/C <PtCu/C < PtCu3/C was revealed. In particular, the specific area activity of PtCu3/C was 2.86 mA·cm-2, which was 3.74 times higher than that of commercial Pt/C (0.94 mA·cm-2), while the electrochemical active area (ECSA) was only half of commercial Pt/C. It indicated the enhanced performance stemmed from the accelerated reaction process instead of the increased reaction site. This was further confirmed by density functional theory (DFT) calculations that the introduction of Cu as well as the formation of CuO phase can promote the hydrolysis reaction, and the subsequent produced *OH can promote the oxidation of CO-like intermediate species into CO2 through the bifunctional mechanism. The current work opens a new avenue for the convenient and controllable synthesis of binary Pt-Cu alloy electrocatalysts on MOR and facilitates the development of high-efficient and low-cost DMFC devices.国家自然科学基金项目(22005300);国家自然科学基金项目(91834301);中国科学院战略性先导科技专项变革性洁净关键技术与示范(XDA21090300)通讯作者:王素力,孙公权E-mail:[email protected];[email protected]:Su-LiWang,Gong-QuanSunE-mail:[email protected];[email protected].中国科学院大连化学物理研究所,辽宁 大连 1160232.中国科学院大学 北京 1000493.吉林大学材料科学与工程学院,吉林 长春 1300121. Chinese Academy of Sciences, Dalian Institute of Chemical Physics, Dalian 116023, Liaoning, China2. University of Chinese Academy of Sciences, Beijing 100049, China3. Jilin University, School of Materials Science and Engineering, Changchun 130012, Jilin, Chin
The data set of dissolved oxygen concentrations in the South China Sea off the Pearl River Estuary in July 2018
No full textWe examined the evolution of intermittent hypoxia off the Pearl River Estuary based on three cruise legs conducted in July 2018: one during severe hypoxic conditions before the passage of a typhoon and two post-typhoon legs showing destruction of the hypoxia and its reinstatement. The lowest ever recorded regional dissolved oxygen (DO) concentration of 3.5 μmol kg-1 (~ 0.1 mg L-1) was observed in bottom waters during Leg 1, with a ~ 660 km2 area experiencing hypoxic conditions (DO < 63 μmol kg-1). Hypoxia was completely destroyed by the typhoon passage but was quickly restored ~ 6 days later, resulting primarily from high biochemical oxygen consumption in bottom waters that averaged 14.6±4.8 μmol O2 kg-1 d-1. The shoreward intrusion of offshore subsurface waters contributed to an additional 8.6±1.7 % of oxygen loss during the reinstatement of hypoxia. Freshwater inputs suppressed wind-driven turbulent mixing, stabilizing the water column and facilitating the hypoxia formation. The rapid reinstatement of summer hypoxia has a shorter timescale than the water residence time, which is however comparable with that of its initial disturbance from frequent tropical cyclones that occur throughout the wet season. This has important implications towards better understanding the intermittent nature of hypoxia and predicting coastal hypoxia in a changing climate
Trisomy 21-induced Dysregulation of Microglial Homeostasis in Alzheimer’s Brains is Mediated by USP25
Full text link阿尔茨海默病（Alzheimer’s disease, AD）是一种最为常见的与记忆、认知能力退化相关的渐进性神经退行性疾病。唐氏综合征（Down’s syndrome, DS）是早发型阿尔茨海默病的一个重要风险因素，作为最常见的智力障碍遗传疾病，厦门大学医学院神经科学研究所王鑫教授团队揭示了治疗阿尔茨海默病和唐氏综合征新的治疗靶点，并且在小鼠模型上利用USP25小分子抑制剂成功地改善了阿尔茨海默病小鼠的认知功能，缓解了神经退行性病变的病理进程。该研究工作由王鑫教授指导完成，厦门大学医学院助理教授郑秋阳和博士生李桂林完成主要实验工作，王世华、朱琳、高月、邓青芳、张洪峰、张丽珊、吴美玲、狄安洁参与了部分研究工作。厦门大学医学院许华曦、赵颖俊和孙灏教授在研究过程中给予大力帮助和支持，清华大学董晨教授提供了Usp25基因敲除小鼠，厦门大学附属妇女儿童医院周裕林教授和郑良楷博士帮助收集了脑组织样品。Down syndrome (DS), caused by trisomy of chromosome 21, is the most significant risk factor for early-onset Alzheimer’s disease (AD); however, underlying mechanisms linking DS and AD remain unclear. Here, we show that triplication of homologous chromosome 21 genes aggravates neuroinflammation in combined murine DS-AD models. Overexpression of USP25, a deubiquitinating enzyme encoded by chromosome 21, results in microglial activation and induces synaptic and cognitive deficits, whereas genetic ablation of Usp25 reduces neuroinflammation and rescues synaptic and cognitive function in 5×FAD mice. Mechanistically, USP25 deficiency attenuates microglia-mediated proinflammatory cytokine overproduction and synapse elimination. Inhibition of USP25 reestablishes homeostatic microglial signatures and restores synaptic and cognitive function in 5×FAD mice. In summary, we demonstrate an unprecedented role for trisomy 21 and pathogenic effects associated with microgliosis as a result of the increased USP25 dosage, implicating USP25 as a therapeutic target for neuroinflammation in DS and AD.This work was supported by the National Natural Science Foundation of China (31871077, 81822014, and 81571176 to X.W.; 81701130 to Q.Z.), the National Key R&D Program of China (2016YFC1305900 to X.W.), the Natural Science Foundation of Fujian Province of China (2017J06021 to X.W.), the Fundamental Research Funds for the Chinese Central Universities (20720150061 to X.W.), and the BrightFocus Foundation (A2018214F to Yingjun Zhao).
该研究工作得到国家重点研发计划项目、国家自然科学基金、福建省自然科学基金、厦门大学校长基金的资助和支持
Monitoring long-term ecological impacts from release of Fukushima radiation water into ocean
No full text4月13日，日本政府宣布其将福岛第一核电站的核废水排入太平洋的决定，尽管其一再强调经过处理和稀释后的核废水的辐射水平会低于饮用水设定的标准，但此举仍遭到当地渔民和附近沿海国家包括韩国、俄罗斯、中国和朝鲜的强烈反对，联合国和包括绿色和平组织等在内的非政府组织对日本这一决定表示深切担忧。国际原子能机构（IAEA）表示会对核废水的排放进行严格监督，保证其在安全水平之内。关于“福岛核辐射”的网络检索量在4月13日激增，此举引起国际上广泛关注。在此背景下，国际期刊Geography and Sustainability邀请欧洲科学院院士、发展中国家科学院院士、我校吕永龙教授研究团队撰写文章，科学分析了日本福岛核事故的生态影响及核废水排放入海会带来的潜在的生态影响，并提出了应采取的应对措施，呼吁国际科技界联合起来对此做出回应。该文的第一与通讯作者为吕永龙教授，共同作者包括苑晶晶博士以及杜荻、孙斌和易小洁三位博士生。参与单位包括厦门大学、中国科学院生态环境研究中心、中国科学院大学和中丹科教中心。【Abstract】After 10 years of the Fukushima Nuclear Accident, Japan decided to release the nuclear wastewater into the Pacific Ocean on 13 April 2021. It is apparent that Japan has chosen the most cost-efficient way to deal with
the contaminated water, however, great opposition and concerns have been raised internationally due to the
ecotoxicological features of radioactive materials and their harmful impacts on the environment. Here we analyze the ecological impacts caused by the nuclear accident and the potential impacts of releasing the nuclear
wastewater into the ocean. Science-based solutions are proposed through a third-party evaluation and strict environmental assessment, multi-stakeholder public participation, integrated monitoring of the neighboring coastal
countries, long-term international collaborative research, and setting up international convention for ecological
compensation.This study was supported by the National Natural Science Foundation of China (Grant No.71761147001 and 42030707) and the International Partnership Program of the Chinese Academy of Sciences (Grant No.121311KYSB20190029).
该研究得到了国家自然科学基金（71761147001和42030707）和中国科学院国际大科学计划项目（121311KYSB20190029）的资助
Organophotocatalytic selective deuterodehalogenation of aryl or alkyl chlorides
No full text氘代标记技术（deuterium-labeling techniques）在有机合成、分析化学、生命科学、药物化学等领域应用广泛。近年来，随着氘代药物的快速兴起，发展经济高效、生命友好的氘化反应已成为化学家和生物学家共同关注的问题。传统氘化反应通常需要过渡金属催化、苛刻反应条件、昂贵氘源等，这些因素对药物开发是不利的。课题组发展了一种共轭芳香胺和烷基二硫醚组成的有机可见光共催化体系。在有机可见光催化芳基、烷基氯代物的选择性氘化研究中取得进展。本工作是课题组首次在无过渡金属催化可见光可控性反应中的尝试，由龚磊教授指导，实验由科研助理李延军（第一作者）和硕士生叶子奇（第二作者）完成，计算由叶子奇完成，林玉妹老师在论文修改方面提出了宝贵意见，刘艳老师、硕士生张于锰在高分辨质谱测试分析中提供了帮助。【Abstract】Development of practical deuteration reactions is highly valuable for organic synthesis,
analytic chemistry and pharmaceutic chemistry. Deuterodehalogenation of organic chlorides
tends to be an attractive strategy but remains a challenging task. We here develop a photocatalytic system consisting of an aryl-amine photocatalyst and a disulfide co-catalyst in the
presence of sodium formate as an electron and hydrogen donor. Accordingly, many aryl
chlorides, alkyl chlorides, and other halides are converted to deuterated products at room
temperature in air (>90 examples, up to 99% D-incorporation). The mechanistic studies
reveal that the aryl amine serves as reducing photoredox catalyst to initiate cleavage of the
C-Cl bond, at the same time as energy transfer catalyst to induce homolysis of the disulfide
for consequent deuterium transfer process. This economic and environmentally-friendly
method can be used for site-selective D-labeling of a number of bioactive molecules and
direct H/D exchange of some drug molecules.We gratefully acknowledge funding from the National Natural Science Foundation of China (grant no. 22071209, 22071206), the Natural Science Foundation of Fujian Province of China (grant no. 2017J06006), and the Fundamental Research Funds for the Central Universities (grant no. 20720190048).研究工作得到国家自然科学基金（22071209、21572184）、“万人计划”青年拔尖人才、福建省杰出青年基金（2017J06006）、厦门大学南强青年拔尖人才计划、厦门大学校长基金（20720190048）等项目支持
Ohmic Drop Compensation in Electrochemical Measurement
No full text对工作电极与参比电极之间的溶液电阻(Ru)进行准确的欧姆电压降补偿是获取可靠的电化学实验结果的前提,但测量中该如何进行补偿尚未建立规范的操作流程。本文首先探究了工作电极与Luggin毛细管末端距离对Ru的影响。随后对比了Autolab PGSTAT 302N、CHI系列恒电位仪的交流阻抗法与CHI系列恒电位仪所测得Ru的差别。并且以铂电极上的氢析出反应为例,探究了灵敏度、补偿百分比以及仪器等因素对补偿后HER极化曲线带来的影响。深入讨论了产生这些偏差的原因,最后给出了规避和减轻此类问题以实现准确有效的欧姆电压降补偿的建议。The solution resistance (Ru) between the working electrode (WE) and the reference electrode (RE) may lead to significant Ohmic drop (iRu) and deviation of actually applied potential at the WE to the desired ones in electrochemical measurement. In the case of high current or large Ru, iRu compensation is imperative. Errors associated with insufficient compensation of theiRu drop may significantly affect the accuracy of data measured by conventional electrochemical methods, which may consequently result in wrong judgment and conclusions. In this article, we discuss important factors which may affect the accuracy of iRu compensation as well as ways how to eliminate such errors through examples. Since Ru will be changed sensitively with the distance between the tip of the Luggin capillary of the RE and the WE, it should always be kept at a fixed distance (usually as close to the surface of the WE as possible but without affecting the behavior of electrode processes) during a set of measurements. In addition to the structure of the cell (relative positions of WE and RE), the methods of measuring Ru, current sensitivity for recording data, percentage of Ru compensation, and instruments could cause the result to be deviated from the actual value, which are demonstrated by taken hydrogen evolution reaction on Pt electrode as model reactions measured using both CHI and Autolab PGSTAT 302N potentiostats. Comparing the AC impedance method with the potential step method in the automatic compensation function of CHI potentiostat, theRu measured by the potential step method was smaller than the Ru measured by the AC impedance method and the actual value. It is suggested to use the AC impedance method to measure Ru, input the resistance value manually and complete the compensation by the instrument. Current sensitivity may limit the maximum Ru to be compensated, hence, one should select the right current sensitivity before recording data. In particular, when compensating by manual input using some types of potentiostat, one should be aware that the software may show the completely compensated resistance, in reality, however, the part of the resistance that exceeded the upper limit will not be compensated successfully. Furthermore, the percentage ofRu compensation should be carefully optimized before carrying out the actual measurements, through comparing curves recorded with different percentages of compensation. Moreover, the same compensation level but conducted with different instruments may lead to significantly different results, using the same instrument in a series study is recommended to mitigate related errors. A set of strict compensation standards applied to all instruments and electrochemical systems is difficult to be established. Hence, we suggest carrying out some control experiments to optimize the iRu compensation before the actual measurements, and write in detail their compensation methods and parameters in the published results, especially the factors mentioned in this paper.国家自然科学基金项目(21972131)通讯作者:陈艳霞E-mail:[email protected]:Yan-XiaChenE-mail:[email protected]合肥微尺度物质科学国家研究中心,中国科学技术大学化学物理系,安徽 合肥 230026Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, 230026, Chin