KH_2PO_4中电子或空穴辅助下的氢缺陷反应

研究了非线性光学晶体材料KH2 PO4(KDP)中不同带电状态的H缺陷的稳定性及其反应 .从而以清晰的物理图像描绘了KDP材料暴露在强紫外线或X射线下性能下降的原因 .研究发现 ,对于H间隙原子 ,当增加一个电子时 ,H间隙原子与主H原子发生作用 ,形成间隙H2 分子并产生一个H空位 ,而增加一个空穴时H间隙原子与临近的主O原子形成氢氧键 ,这两种带电态的H间隙原子均切断KDP材料中形成网络的氢键 ;对于H空位 ,增加一个空穴将导致形成“过氧化氢”桥结构 .

强迫症患者反应抑制缺陷及注意的调节作用

使用内外源线索结合不同冲突水平的侧抑制任务,考察强迫症患者对分心刺激的抑制有无缺陷、注意定向对分心刺激的干扰效应有无调节作用及在何水平上发挥作用。结果表明:强迫症患者不同冲突水平的侧抑制任务均无明显反应抑制缺陷,可能与其注意威胁性信息等有关;集中注意在知觉冲突水平上对强迫症患者和正常人的反应冲突进行调节且无显著性差异,可能与强迫症患者关注内容非空间定向有关。

NaCl(OH^-)色心晶体制备中的固态缺陷化学反应(英文)

采用提拉法生长单晶,通过附加金属着色、淬火、室温和液氮温度光聚集等过程,制备了NaCl: (F+2 )H色心激光晶体。研究了NaCl(OH- )晶体中色心形成的固态化学反应,结果表明在附加着色过程中发生了热形成、热聚集、热结合和可逆反应,在淬火过程中发生了热分解和可逆反应,在光聚集过程中,发生了光聚集反应、异构化反应和可逆反应。

托莫西汀治疗注意缺陷/多动障碍患儿的常见不良反应及安全性研究

目的:了解托莫西汀治疗注意缺陷/多动障碍(ADHD)患儿的常见不良反应及安全性,为临床用药提供参考。方法:以"托莫西汀""注意缺陷/多动障碍""不良反应""安全性""患儿""Atomoxetine""Attention deficit hyperactivity disorder""Safety""Adverse effect""Children patient"等为关键词,组合查询中国知网、万方数据、Pub Med等数据库中的相关文献,检索时限均为各数据库建库起至2017年,对托莫西汀常见不良反应及安全性研究进行论述。结果与结论:共检索到相关文献82篇,其中有效文献47篇。托莫西汀常见不良反应包括胃肠道不良反应、体质量下降、心血管相关不良反应、肝功能相关不良反应和精神相关不良反应。其中,最常见的不良反应为胃肠道不良反应和体质量下降,两者可能存在相关性;心血管相关不良反应也较常见,主要表现为血压的升高和QT间期的延长,但是程度轻微;肝功能不良反应发生率较低,一般表现为丙氨酸转氨酶、天冬氨酸转氨酶、碱性磷酸酶和总胆红素的轻微增加,但对于肝功能不全的ADHD患儿,应该考虑降低剂量以及严密检测肝功能;托莫西汀的精神相关不良反应,如自杀倾向、敌对/攻击行为、躁狂等,发生率较低,但对于ADHD合并其他精神相关疾病的患儿,应该严密监测精神相关不良反应的发生。

SrTiO_3的缺陷化学

系统分析了有关ＳｒＴｉＯ３的缺陷化学的文献报道，在此基础上给出了未掺杂、受主和施主掺杂ＳｒＴｉＯ３的缺陷反应方程、平衡常数、各种缺陷的生成自由能和生成焓．由此可以计算和预测ＳｒＴｉＯ３主要点缺陷的浓度．

多动症患儿的持续反应抑制缺陷与其注意水平、冲动行为的关系

目的 研究多动症(ADHD)患儿的持续反应抑制缺陷与注意水平、冲动行为的关系。方法 选择本院儿科2020年1月~2022年5月134例多动症患儿作为研究对象,均行视觉持续性操作测验(CPT)。比较不同视觉CPT错误率患儿的中文版注意缺陷多动症障碍父母评定量表第4版(SNAP-IV)、Conners儿童行为父母问卷。结果 134例患儿中视觉CPT错误率≤10%者35例,11%~30%者64例,>30%者35例。错误率≤10%组的注意缺陷分量表、多动/冲动分量表评分及SNAP-IV总分均显著低于错误率11%~30%组和错误率>30%组,差异有统计学意义(P<0.05)。错误率≤10%组的品行问题、学习问题、心身障碍、冲动-多动、多动指数评分均显著低于错误率11%~30%组和错误率>30%组,差异有统计学意义(P<0.05);三组的焦虑评分无统计学意义的差异(P>0.05)。经Pearson直线相关法分析,多动症患儿的持续反应抑制缺陷与注意水平呈负相关,与冲动行为呈正相关(P<0.05)。结论 多动症患儿的持续反应抑制缺陷越严重,其注意水平越差,冲动行为越明显。

TiO_2压敏电阻表面层的测定与分析

采用电子陶瓷工艺制备了(Nb,La)掺杂的TiO2压敏电阻。用电子探针微区成分分析方法测定了样品中氧含量随深度的变化关系。结果表明,样品表面处氧的含量高于理论值,内部低于理论值,表面“氧化层”的厚度约为20μm。利用缺陷反应和扩散原理对表面层效应进行了初步分析,指出表面层效应的研究对改善和调节材料的电学性能具有重要的指导意义。

光诱导纳米二氧化钛超亲水薄膜SPM图像分析和氧空位浓度理论探讨

选用典型的二氧化钛纳米超亲水薄膜 ,用扫描探针显微镜 (SPM )和电化学测试系统进行一般性的表征 .着重运用固体化学和纳米力学的原理 ,对SPM图像、氧空位浓度和超亲水性的机理进行理论分析 ;进一步解释了作者于 1999年底提出的 ,与润湿性能有关的二氧化钛缺陷生成反应方程、普适表面物理模型、两憎 (amphiphobic)

瑞舒伐他汀对动脉粥样硬化斑块中补体因子H表达的影响

目的研究瑞舒伐他汀对载脂蛋白E基因缺陷小鼠(ApoE-/-小鼠)动脉粥样硬化处补体因子H(CFH)表达的影响。方法 8周龄ApoE-/-小鼠随机分为4组:模型组Ⅰ(高脂饲料喂养10周)、模型组Ⅱ(高脂饲料喂养20周)、预防组(在给予高脂饲料的同时予瑞舒伐他汀预防性给药10周)和治疗组(于高脂饲料喂养10周后,给予瑞舒伐他汀,喂至20周)。阶段试验结束时取主动脉做HE染色及免疫组化,检测CFH mRNA转录和蛋白表达水平;检测血脂及血清hsCRP、C3a水平。结果与模型组Ⅰ和模型组Ⅱ比较,预防组及治疗组ApoE-/-小鼠主动脉内膜和斑块内CFH表达增多;CFH的mRNA转录水平和蛋白表达水平升高;血脂、hsCRP、C3a水降低(P<0.01或0.05)。结论瑞舒伐他汀降低血脂水平,降低动脉粥样硬化的炎症免疫反应,增加CFH表达。

酸洗技术在轴承加工中的应用

介绍了不同金属材料轴承零件的酸洗工艺及酸洗液配方 ,讨论了酸洗、明化反应的机理 ,分析了酸洗显示的轴承零件加工缺陷产生的原因。

Synergistic integration of metallic Bi and defects on BiOI: Enhanced photocatalytic NO removal and conversion pathway

Surface plasmon resonance(SPR)of metals may provide a way to improve light absorption and utilization of semiconductors,achieving better solar light conversion and photocatalysis efficiency.This study uses the advantages of SPR in metallic Bi and artificial defects to cooperatively enhance the photocatalytic performance of BiOI.The catalysts were prepared by partial reduction of BiOI to form Bi@defective BiOI,which showed highly enhanced visible photocatalytic activity for NOx removal.The effects of reductant quantity on the photocatalytic performance of Bi@defective BiOI were investigated.The as-prepared photocatalyst(Bi/BiOI-2)using 2 mmol of reductant NaBH4 showed the most efficient visible light photocatalytic activity.This enhanced activity can be ascribed to the synergistic effects of metallic Bi and oxygen vacancies.The electrons from the valence band tend to accumulate at vacancy states;therefore,the increased charge density would cause the adsorbed oxygen to transform more easily into superoxide radicals and,further,into hydroxyl radicals.These radicals are the main active species that oxidize NO into final products.The SPR effect of elemental Bi enables the improvement of visible light absorption efficiency and the promotion of charge carrier separation,which are crucial factors in boosting photocatalysis.NO adsorption and reaction processes on Bi/BiOI-2 were dynamically monitored by in situ infrared spectroscopy(FT-IR).The Bi/BiOI photocatalysis mechanism co-mediated by elemental Bi and oxygen vacancies was proposed based on the analysis of intermediate products and DFT calculations.This present work could provide new insights into the design of high-performance photocatalysts and understanding of the photocatalysis reaction mechanism for air-purification applications.

A review of defect engineering in two‐dimensional materials for electrocatalytic hydrogen evolution reaction

The exploration of efficient and earth‐rich electrocatalysts for electrochemical reactions is critical to the implementation of large‐scale green energy conversion and storage techniques.Two‐dimensional(2D)materials with distinctive structural and electrochemical properties provide fertile soil for researchers to harvest basic science and emerging applications,which can be divided into metal‐free materials(such as graphene,carbon nitride and black phosphorus)and transition metal‐based materials(such as halogenides,phosphates,oxides,hydroxides,and MXenes).For faultless 2D materials,they usually exhibit poor electrochemical hydrogen evolution reaction(HER)activity because only edge sites can be available while the base surface is chemically inactive.Defect engineering is an effective strategy to generate active sites in 2D materials for improving electrocatalytic activity.This review presents feasible design strategies for constructing defect sites(including edge defects,vacancy defects and dopant derived defects)in 2D materials to improve their HER performance.The essential relationships between defect structures and electrocatalytic HER performance are discussed in detail,providing valuable guidance for rationally fabricating efficient HER electrocatalysts.The hydrogen adsorption/desorption energy can be optimized by constructing defect sites at different locations and by adjusting the local electronic structure to form unsaturated coordination states for efficient HER.

Amorphous Ru nanoclusters onto Co‐doped 1D carbon nanocages enables efficient hydrogen evolution catalysis

The development of high-performance electrocatalysts for hydrogen evolution reaction(HER)is of great significance for green,sustainable,and renewable energy conversion.Herein,we report the synthesis of amorphous Ru clusters on Co-doped defect-rich hollow carbon nanocage(a-Ru@Co-DHC)as an efficient electrocatalyst for HER in the basic media.Due to the advantages such as high surface area,rich edge defect,atomic Co doping and amorphous Ru clusters,the as-made a-Ru@Co-DHC displays an efficient HER performance with a near-zero onset overpotential,a low Tafel slope(62 mV dec^(−1)),a low overpotential of 40 mV at 10 mA cm^(−2) and high stability,outperforming the commercial Ru nanocrystal/C,commercial Pt/C,and other reported Ru-based catalysts.This work provides a new insight into designing new metal doped carbon nanocages catalysts supported by amorphous nanoclusters for achieving the enhanced electrocatalysis.

Lack of Response in Severe Pneumocystis Pneumonia to Combined Caspofungin and Clindamycin Treatment: a Case Report

PNEUMOCYSTIS pneumonia (PCP) is among the most common opportunistic infections in patients with acquired immune deficiency syndrome (AIDS).Although trimethoprim-sulfamethoxazole (TMP-SMX) is the first line therapy for that condition given its efficacy,approximately one third of patients experienced dose-limiting toxicity.1 For cases of severe to moderate PCP,if TMP-SMX treatment fails or is contraindicated,primaquine combined with clindamycin or intravenous pentamidine is recommended as second line therapy.2 However,both primaquine and pentamidine are associated with severe adverse reactions and often unavailable at hospitals in China.3 As a result,other treatment options have been explored.

Pivotal roles of artificial oxygen vacancies in enhancing photocatalytic activity and selectivity on Bi_2O_2CO_3 nanosheets

There is an increasing interest in bismuth carbonate(Bi2O2CO3,BOC)as a semiconductor photocatalyst.However,pure BOC strongly absorbs ultraviolet light,which drives a high recombination rate of charge carriers and thereby limits the overall photocatalysis efficiency.In this work,artificial oxygen vacancies(OV)were introduced into BOC(OV-BOC)to broaden the optical absorption range,increase the charge separation efficiency,and activate the reactants.The photocatalytic removal ratio of NO was increased significantly from 10.0%for pure BOC to 50.2%for OV-BOC because of the multiple roles played by the oxygen vacancies.These results imply that oxygen vacancies can facilitate the electron exchange between intermediates and the surface oxygen vacancies in OV-BOC,making them more easily destroyed by active radicals.In situ DRIFTS spectra in combination with electron spin resonance spectra and density functional theory calculations enabled unraveling of the conversion pathway for the photocatalytic NO oxidation on OV-BOC.It was found that oxygen vacancies could increase the production of active radicals and promote the transformation of NO into target products instead of toxic byproducts(NO2),thus the selectivity is significantly enhanced.This work provides a new strategy for enhancing photocatalytic activity and selectivity.

Platinum stabilized by defective activated carbon with excellent oxygen reduction performance in alkaline media

The exploration of highly active and durable cathodic oxygen reduction reaction(ORR)catalysts with economical production cost is still the bottleneck to realize the large‐scale commercialization of fuel cells and metal‐air batteries.Given that carbon support is crucial to the electrocatalysts,and Pt is the best‐known ORR catalyst so far,in this work,we employed a simple impregnation method for synthesizing a kind of defective activated carbon(D‐AC)supported low Pt content electrocatalysts for the ORR.The reduction conditions of the Pt‐containing precursor were firstly optimized,and the influence of the Pt loading amount on the ORR was investigated as well.The results show that the obtained D‐AC@5.0%Pt sample(contains5wt%Pt)has surpassed the commercial Pt/C with20wt%Pt for the ORR in an alkaline solution.In the meantime,it is more stable than the commercial Pt/C.The outstanding ORR performance of the D‐AC@5.0%Pt confirms that both the unique defects in the D‐AC and the introduced Pt particles are indispensable to the ORR.Particularly,m the ORR activity of the synthesized catalysts is superior to most of the reported counterparts,but with much easier preparation methods and lower production cost,making them more advantageous in practical fuel cell applications.

“Anti-HBc alone” in human immunodefi ciency virus-positive and immuno-suppressed lymphoma patients

Hepatitis B virus (HBV) infection is endemic in various parts of the world. A proportion of patients have resolved prior exposure to HBV, as evidenced by the clearance of circulating hepatitis B surface antigen and the appearance of antibody to hepatitis B core antigen (anti-HBc), which could produce protective antibody to hepatitis B surface antigen (anti-HBs). With time, anti-HBs in some patients may become negative. Such patients are described as having occult HBV infection or "anti-HBc alone". In the context of immunodef icient patients, such as HIV patients or lymphoma patients undergoing immunosuppressive immunotherapy, the lack of protective anti-HBs may increase the risk of hepatitis B reactivation. Serum HBV DNA testing may be necessary in "anti-HBc alone" patients, to detect patients at a high risk of developing HBV infection allowing appropriate prophylactic management.

Defective high-entropy rocksalt oxide with enhanced metal‒oxygen covalency for electrocatalytic oxygen evolution

High‐entropy materials are emerging electrocatalysts by integrating five or more elements into one single crystallographic phase to optimize the electronic structures and geometric environments.Here,a rocksalt‐type high‐entropy oxide Mg_(0.2)Co_(0.2)Ni_(0.2)Cu_(0.2)Zn_(0.2)O(HEO)is developed as an electrocatalyst towards the oxygen evolution reaction(OER).The obtained HEO features abundant cation and oxygen vacancies originating from the lattice mismatch of neighboring metal ions,together with enlarged Co/Ni‒O covalency due to the introduction of less electronegative Mg and Zn.As a result,the HEO exhibits superior intrinsic OER activities,delivering a turnover frequency(TOF)15 and 84 folds that of CoO and NiO at 1.65 V,respectively.This study provides a mechanistic understanding of the enhanced OER on HEO and demonstrates the potential of high‐entropy strategy in developing efficient oxygen electrocatalysts by elaborately incorporating low‐cost elements with lower electronegativity.

Pinpointing single metal atom anchoring sites in carbon for oxygen reduction: Doping sites or defects?

Enabling the conversion of chemical energy of fuels directly into electricity without combustion,fuel cells are arousing great interest in both academia and industry.A typical case is the proton exchange membrane fuel cell(PEMFC),already commercialized by automobile giants.For mass popularization,however,three major criteria must be balanced:performance,durability and cost.The electrocatalysts used in both the anode and cathode are the kernel of PEMFCs,being essential for efficient operation.First in the firing‐line is the oxygen reduction reaction(ORR)at the cathode,which is normally very sluggish:over six orders of magnitude slower than the anode hydrogen oxidation reaction(HOR)[1].Thus,considerable efforts have been made to improve the cathode ORR.Identifying the main active sites is key to the design of optimum materials for enhanced ORR.Considering the complex balance of preparation,performance and cost,the active sites of metal‐nitrogen‐carbon(M‐N‐C)catalysts are particularly promising.Coupled with the single metal atom(SMA)catalysts[2–5],two excellent M‐N‐C catalysts were recently reported[6,7].New insights were thereby gained into the delicate architecture of carbon‐based SMA catalysts for ORR.