mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
Modeling thermal and mechanical cancellation of residual stress from hybrid additive manufacturing by laser peening

Additive manufacturing (AM) of metals often results in parts with unfavorable mechanical properties. Laser peening (LP) is a high strain rate mechanical surface treatment that hammers a workpiece and induces favorable mechanical properties. Peening strain hardens a surface and imparts compressive residual stresses improving the mechanical properties of a material. This work investigates the role of LP on layer-by-layer processing of 3D printed metals using finite element analysis. The objective is to understand temporal and spatial residual stress development after thermal and mechanical cancellation caused by cyclically coupling printing and peening. Results indicate layer peening frequency is a critical process parameter affecting residual stress redistribution and highly interdependent on the heat generated by the printing process. Optimum hybrid process conditions were found to exists that favorably enhance mechanical properties. With this study, hybrid-AM has ushered in the next evolutionary step in AM and has the potential to profoundly change the way high value metal goods are manufactured.
Fetuin-A基因多态性与多囊卵巢综合征的相关性分析

目的探讨Fetuin-A基因位点rs1071592及rs2593813多态性与PCOS的相关性。方法选择重庆市中医院2015年3月至2018年3月收治的PCOS患者260例为PCOS组。以同期264例健康体检者为对照组。收集临床资料。采用荧光定量PCR技术检测两位点的基因型和等位基因。分析PCOS发病的风险等位基因。结果PCOS组rs1071592的AA基因型及A等位基因均高于对照组,差异有统计学意义(P < 0.05);PCOS患者携带AA基因型发病风险是CC基因型的4.85倍;显性模型AA+AC组BMI、空腹胰岛素、胰岛素抵抗指数均高于CC组,葡萄糖代谢率低于CC组,差异均有显著性(P < 0.05);隐性模型AA组空腹胰岛素、胰岛素抵抗指数均高于AC+CC组,葡萄糖代谢率低于AC+CC组,差异均有统计学意义(P < 0.05)。结论Fetuin-A基因rs1071592多态位点与PCOS遗传易感性存在相关。
子痫前期孕妇血清和胎盘脂联素、瘦素、胱抑素C水平变化及临床意义

目的观察子痫前期孕妇血清和胎盘脂联素、瘦素、胱抑素C水平变化及其意义。方法选取安徽省淮南市第一人民医院妇产科确诊的子痫前期孕妇124例,分为重度子痫前期(重度组,n =68)和轻度子痫前期(轻度组,n =56),选取同期分娩的正常孕妇30例为对照组。检测三组孕妇血清和胎盘的脂联素、瘦素、胱抑素C水平。结果重度组和轻度组血清脂联素水平明显低于对照组(P < 0.05),重度组低于轻度组(P < 0.05)。重度组和轻度组血清瘦素、胱抑素C水平明显高于对照组(P < 0.05),重度组高于轻度组(P < 0.05)。三组间胎盘脂联素、瘦素和胱抑素C表达差异有统计学意义(P < 0.05)。结论脂联素、瘦素和胱抑素C与子痫前期的发生发展密切相关。
妊娠期维生素C、E及微量元素铜、锌与子痫前期相关性研究

目的探讨妊娠期维生素C、E及微量元素铜、锌与子痫前期发生的相关性。方法研究纳入2016年8至2017年12月53例具有妊娠期高血压高危因素的宫内单胎孕妇患者为研究对象(子痫前期组),并选择孕周与之相匹配的53例正常孕妇为对照组。测定血清中维生素C、E及微量元素铜(Cu)、锌(Zn)含量,分析组间差异。结果子痫前期组维生素C、E、微量元素Zn含量均低于正常对照组[(4.0±1.1)μg /ml vs (6.1±1.3)μg /ml、(10.56±2.17)μg /ml vs (18.94±3.17)μg /ml、(10.30±2.98)μmol/L vs (13.44±2.33) μmol/L,P < 0.05],微量元素Cu高于对照组[(16.73±3.71)μg /ml vs (13.29±2.25)μg /ml,P < 0.05]。维生素C、E及微量元素Zn水平的关系与子痫前期呈负相关(r =- 0.411、- 0.722,P < 0.05),微量元素Cu与子痫前期呈正相关(r =0.535,P < 0.05)。血清维生素C、E及微量元素Zn下降,微量元素Cu升高是妊娠晚期发生子痫前期的危险因素(P < 0.01)。结论妊娠期维生素C、E及微量元素铜、锌代谢异常与子痫前期发生密切相关,妊娠期维持营养均衡可在一定程度上预防子痫前期发生。
会阴超声在西宁地区妇女孕期及产后盆底变化的应用研究

目的对比研究会阴超声在妇女孕期及产后盆底变化中的诊断价值,为产后妇女筛查盆底功能及康复治疗提供影像学依据。方法观察组50例初孕妇女,产前、产后不同时期盆底各项指标的变化,探讨超声在盆底功能障碍性疾病中应用价值。结果孕晚期膀胱下移距离、尿道旋转角度大于孕早期;产后半年膀胱下移距离、尿道旋转角度较产后早期减轻;产后与孕期比较,产后膀胱下移程度明显增大,两者差异有统计学意义 (P < 0.05)。结论初产妇盆底功能障碍改变主要以前盆腔器官改变为主,超声能评估盆腔器官脱垂程度,为盆底无创性康复治疗提供影像学依据。
A Q-switched erbium-doped fiber laser based on ZrS_2 as a saturable absorber

A passively Q-switched erbium-doped fiber (EDF) laser is proposed and demonstrated utilizing a zirconium disulfide (ZrS_2)-based saturable absorber (SA). ZrS_2 nanosheets are prepared, whose modulation depth, saturation intensity, and nonsaturable absorbance are measured to be 14.7%, 0.34 MW/cm~2, and 17.4%, respectively. Then, a Q-switched EDF laser is implemented by the ZrS_2-SA. The pulse repetition rate varies from 40.65 to 87.1 kHz when the pump power changes from 55 to 345 mW. The shortest pulse width is 1.49 μs with pulse energy of 33.5 nJ. As far as we know, this is the shortest pulse width obtained by a ZrS_2-SA so far.
Ag/reduced graphene oxide(RGO) nanocomposites for detection of TNT

The modified Hummers method was employed to generate graphene oxide,and Ag/reduced graphene oxide (RGO) nanocomposites were synthesized at different temperatures by using sodium citrate as the reductant. Scanning electron microscopy (SEM),transmission electron microscopy (TEM),X-ray diffraction (XRD),X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy were employed to characterize the reaction products. The results indicate that RGO has been synthesized successfully,and Ag particles are distributed evenly on the surface of RGO. The RGO prepared at a reaction temperature of 120℃ shows the best surface-enhanced Raman scattering (SERS) activity. The Ag/RGO nanocomposites modified by 10 - 5 mol/L 4-aminothiophenol (PATP) successfully detect a 10 ~(- 5) mol/L 2,4,6-trinitrotoluene (TNT) alcohol solution.
An Efficient Adaptive Hierarchical Sliding Mode Control Strategy Using Neural Networks for 3D Overhead Cranes

In this paper, a new adaptive hierarchical sliding mode control scheme for a 3D overhead crane system is proposed. A controller is first designed by the use of a hierarchical structure of two first-order sliding surfaces represented by two actuated and un-actuated subsystems in the bridge crane. Parameters of the controller are then intelligently estimated, where uncertain parameters due to disturbances in the 3D overhead crane dynamic model are proposed to be represented by radial basis function networks whose weights are derived from a Lyapunov function. The proposed approach allows the crane system to be robust under uncertainty conditions in which some uncertain and unknown parameters are highly difficult to determine. Moreover, stability of the sliding surfaces is proved to be guaranteed. Effectiveness of the proposed approach is then demonstrated by implementing the algorithm in both synthetic and reallife systems, where the results obtained by our method are highly promising.
Seismic wave input method for three-dimensional soil-structure dynamic interaction analysis based on the substructure of artifi cial boundaries

The method of inputting the seismic wave determines the accuracy of the simulation of soil-structure dynamic interaction. The wave method is a commonly used approach for seismic wave input, which converts the incident wave into equivalent loads on the cutoff boundaries. The wave method has high precision, but the implementation is complicated, especially for three-dimensional models. By deducing another form of equivalent input seismic loads in the fi nite element model, a new seismic wave input method is proposed. In the new method, by imposing the displacements of the free wave fi eld on the nodes of the substructure composed of elements that contain artifi cial boundaries, the equivalent input seismic loads are obtained through dynamic analysis of the substructure. Subsequently, the equivalent input seismic loads are imposed on the artifi cial boundary nodes to complete the seismic wave input and perform seismic analysis of the soil-structure dynamic interaction model. Compared with the wave method, the new method is simplifi ed by avoiding the complex processes of calculating the equivalent input seismic loads. The validity of the new method is verifi ed by the dynamic analysis numerical examples of the homogeneous and layered half space under vertical and oblique incident seismic waves.
宫腔镜诊治早期输卵管间质部妊娠9例临床分析

目的:探讨宫腔镜在诊治早期输卵管间质部妊娠(IP)中的临床价值。方法:回顾分析2015年3月至2019年3月于湘雅三医院成功应用宫腔镜诊治的9例早期IP患者的临床资料。结果:9例患者术前B超均诊断为宫角妊娠,经宫腔镜检查协助明确诊断为IP;9例患者均在宫腔镜下完成手术操作,其中4例因孕囊较大同时行腹腔镜监护。术中出血20~100ml,术中、术后无明显的手术并发症发生。结论:宫腔镜手术可用于诊断和治疗早期IP,具有简单、安全、有效、微创等优势。
基于E-CHAID算法胆囊结石患者DRGs分组研究

目的探索本地区胆囊结石患者住院费用病例组合模式。方法收集某医院2015-2017年1448例胆囊结石患者信息,采用单因素分析、多元线性回归分析及决策树模型的E-CHAID算法进行病例组合分析。结果年龄、住院天数、手术情况三个分类节点将1448例患者分为6个DRGs组合和相应的标准费用、线外费用情况。结论ECHAID决策树分类算法能充分反映病情复杂程度对医疗资源消耗的影响及不同病例组合的费用差异度,可使DRGs分组更为合理。
16905例院前急救患者流行病学分析

目的分析石河子市2015-2017年院前急救流行病学特征,为制定合理的院前急救策略及有效利用急救资源提供参考。方法从石河子市120调度指挥中心系统数据库中调取2015-2017年数据,对院前急救患者的性别、年龄、出诊时间、疾病谱分布等流行病学资料进行统计分析。结果2015-2017年16905次院前急救出诊患者中,分布高的月份依次是7月、6月、5月,高时间段依次是12∶ 00 ~ 13∶ 59、10∶ 00 ~ 11∶ 59、14∶ 00 ~ 15∶ 59,圆形分布显示高峰日期和时段分别为8月10日(3月17日~次年1月4日) 、16∶ 50(6∶ 30 ~ 3∶ 09);男女比例为1.43∶ 1,排名前3位的疾病是心脑血管疾病(23.6%) 、创伤(21.04%) 、症状体征(9.56%);心脑血管疾病的高峰日期和时段分别为2月12日(7月11日-次年4月17日) 、15: 36(8: 52 ~ 22: 19);创伤的高峰日期和时段分别为8月2日(4月26日-11月8日) 、18: 28(11∶ 48 ~ 1∶ 03);症状体征的高峰日期和时段分别为7月23日(3月1日-12月14日) 、16∶ 07(9∶ 52 ~ 22∶ 19) 。结论院前急救高峰时点和时段应加强院前急救力量,根据流行病学分布特征完善相关的救治流程和应急预案,加强医护人员相关知识和技能培训,合理调配人力资源,提高院前急救水平。
腹膜透析患者肺动脉高压的危险因素分析

本研究为单中心、回顾性研究,纳入2017年1月至2018年12月在广西医科大学第一附属医院随访的持续性不卧床腹膜透析(CAPD)患者131例,按有无肺动脉高压(pulmonary hypertension,PH)分为PH组(34例)和无PH (NPH)组(97例)。结果发现,PH患病率为26.6%,左心房扩大率为46.6%。PH组的左房内径、左室舒张末径、左室收缩末径、室间隔厚度、左室后壁厚度、左心室质量指数、收缩压(SBP)高于NPH组,而射血分数和血白蛋白(Alb)低于NPH组(均P<0.05)。Logistic回归分析提示,SBP升高(OR=1.024,95%CI 1.001 ~ 1.047,P=0.041)、Alb下降(OR=0.897,95%CI 0.813 ~ 0.991,P=0.032)及左房内径增大(OR= 1263,1.135 ~ 1.406,P< 0.001)是CAPD患者PH的独立危险因素。作者认为,积极防治高血压、低蛋白血症和左心房扩大,可能降低CAPD患者发生PH的风险。
重视机械通气患者镇静镇痛个体化策略

镇静镇痛治疗是机械通气患者治疗的重要组成部分,随着指南不断地更新,指导临床镇静镇痛治疗的理念与策略也逐步发生转变,以达到最佳治疗效果,提高患者的舒适性与安全性。本文简述镇静镇痛指南演变,探讨临床中面临的问题,提出目前治疗的策略和建议。
Formation of the front-gradient bandgap in the Ag doped CZTSe thin films and solar cells

The graded bandgap of kesterite based absorber layer is an important way to achieve high efficiency solar cells. Incorporation of Ag into CZTSSe thin films can adjust the bandgap and thus reduce the VOC-deficit and improve the quality of crystallization. However, the distribution of Ag is difficult to control due to the quick diffusion of Ag under the high temperature. In this study, we achieve the front Ag-gradient in kesterite structured compound films by prealloying followed by selenization process at 550 °C. AgZn3, Ag3Sn, and Sn–Ag–Cu alloy phases were formed during prealloying stage at 250 °C. After prealloying process, Ag tends to distribute at the front surface of the ACZTSe thin films. Combining the results of experiment and SCAPS simulation, the significantly VOC improvement of devices is ascribed to the formation of the front Ag-gradient bandgap structure in the absorber layer. This facile prealloying selenization process affords a feasible method to design the graded bandgap structure absorber layers, which will promote the fabrication of high efficient graded bandgap structure solar cells.
Effect of electrode Pt-loading and cathode flow-field plate type on the degradation of PEMFC

The electrode Pt-loading has an effect on the number of active sites and the thickness of catalyst layer, which has huge influence on the mass transfer and water management during dynamic process in PEMFCs. In this study, membrane electrode assemblies with different Pt-loadings were prepared, and PEMFCs were assembled using those membrane electrode assemblies with traditional solid plate and water transport plate as cathode flow-field plates, respectively. The performance and electrochemical surface area of cells were characterized to evaluate the membrane electrode assemblies degradation after rapid currentvariation cycles. Scanning electron microscope and transmission electron microscope were used to investigate the decay of catalyst layers and Pt/C catalyst. With the increase of Pt-loading, the performance degradation of membrane electrode assemblies will be mitigated. But higher Pt-loading means thicker catalyst layer, which leads to a longer pathway of mass transfer, and it may result in carbon material corrosion in membrane electrode assemblies. The decay of Pt/C catalyst in cathode is mainly caused by the corrosion of carbon support, and the degradation of anode Pt/C catalyst is a consequence of migration and aggregation of Pt particles. And using water transport plate is beneficial to alleviating the age of cathode Pt/C catalyst.
Facile synthesis and enhanced catalytic activity of electrochemically dealloyed platinum–nickel nanoparticles towards formic acid electro-oxidation

To obtain the electrocatalyst with an improved electrocatalytic performance towards formic acid electrooxidation (FAEO), a simple impregnation method is used to prepare Pt3Ni nanoparticles loaded on carbon black, assisted with electrochemically dealloying process. The X-ray powder diffraction (XRD) results as well as transmission electron microscopy (TEM) analysis of as-synthesized electrocatalyst demonstrates that the reduction temperature has a great influence on the FAEO activity of the dealloyed Pt3Ni nanoparticles. X-ray photoelectron spectroscopy (XPS) analyses confirm the variation in the electronic structure of platinum by incorporation of nickel atoms which reduces chemisorption of toxic carbon monoxide and promotes the dehydrogenation pathway of FAEO. The size of the dealloyed Pt3Ni nanoparticles remains within the range of about 2.7 nm. All electrochemical results illustrate that the performance of the asobtained electrocatalyst towards the FAEO is significantly enhanced. Moreover, the carbon black content, incorporation of Ni atoms, and reduction temperature conditions have been proven to be the key factors for modification of the crystal structure and morphology which leads to enhanced catalytic performance.
Transforming Co_3O_4 nanosheets into porous N-doped Co_xO_y nanosheets with oxygen vacancies for the oxygen evolution reaction

Cobalt oxides have been widely investigated as promising replacements for noble metal-based catalysts for oxygen evolution reaction (OER). Herein, we, for the first time, have obtained porous Co_xO_y nanosheets with N-doping and oxygen vacancies by etching Co_3O_4 nanosheets with NH3 plasma. Comparing with the pristine Co_3O_4 nanosheets (1.79 V), the porous Co_xO_y nanosheets with N-doping and oxygen vacancies have a much lower potential of 1.51 V versus RHE to reach the current density of 10mA cm~(–2). The obtained sample has a lower Tafel slope of 68mV dec–1 than the pristine Co_3O_4 nanosheets (234mV dec~(–1)). The disclosed Co~(2+), which is responsible for the formation of active sites (CoOOH), N-doping and oxygen vacancies, gives rise to better performance of OER.
Strongly coupled N-doped carbon/Fe_3O_4/N-doped carbon hierarchical micro/nanostructures for enhanced lithium storage performance

A strong interface coupling is of vital importance to develop metal oxide/carbon nanocomposite anodes for next-generation lithium ion batteries. Herein, a rational N-doped carbon riveting strategy is designed to boost the lithium storage performance of Fe_3O_4/N-doped carbon tubular structures. Polypyrrole (PPy) has been used as the precursor for N-doped carbon. N-doped carbon-riveted Fe_3O_4/N-doped carbon (N–C@Fe_3O_4@N–C) nanocomposites were obtained by pyrolysis of PPy-coated FeOOH@PPy nanotubes in Ar atmosphere. When tested as an anode for LIBs, the N–C@Fe_3O_4@N–C displays a high reversible discharge capacity of 675.8mA h g~(–1) after 100 cycles at a current density of 100mA g~(–1) and very good rate capability (470mA h g~(–1) at 2 A g~(–1)), which significantly surpasses the performance of Fe_3O_4@N–C. TEM analysis reveals that after battery cycling the FeOx particles detached from the carbon fibers for Fe_3O_4@N–C, while for N–C@Fe_3O_4@N–C the FeOx particles were still trapped in the carbon matrix, thus preserving good electrical contact. Consequently, the superior performance of N–C@Fe_3O_4@N–C is attributed to the synergistic effect between Fe_3O_4 and N-doped carbon combined with the unique structure properties of the nanocomposites. The strategy reported in this work is expected to be applicable for designing other electrode materials for LIBs.
Wet-spun poly(ionic liquid)-graphene hybrid fibers for high performance all-solid-state flexible supercapacitors

It is crucial to develop flexible and wearable electronic devices that have attracted tremendous interest due to their merits on compactness, flexibility and high capacitive properties. Herein we report the continuously ordered macroscopic poly(ionic liquid)-graphene fibers by wet spinning method via liquid crystal assembly for supercapacitor application. The fabricated all-solid-state supercapacitors exhibited a high areal capacitance (268.2 mF cm~(–2)) and volumetric capacitance (204.6 F cm~(–3)) with an outstanding areal energy density (9.31 μWh cm~(–2)) and volumetric energy density (8.28 mWh cm~(–3)). The fiber supercapacitors demonstrated exceptional cycle life for straight electrodes of about 10,000 cycles (94.2% capacitance retention) and flexibility at different angles (0°, 45°, 90°, 180°) along with a good flexible cycling stability after 6000 cycles (92.7% capacitance retention). To date, such a novel poly (ionic liquid)-graphene fiber supercapacitors would be a new platform in real-time flexible electronics.
P-doped electrode for vanadium flow battery with high-rate capability and all-climate adaptability

A phosphorous-doped graphite felt (PGF) is fabricated and examined as electrode for vanadium flow battery (VFB). P doping improves the electrolyte wettability of GF and induces more defect sites on its surface, resulting in significantly enhanced activity and reversibility towards VO~(2+)/VO~(2 +) and V~(2+)/V~(3+) couples. VFB with PGF electrode demonstrates outstanding performance such as high-rate capability under 50–400mA cm~(–2), wide-temperature tolerance at –20 °C–60 °C, and excellent durability over 1000 charge–discharge cycles. These merits enable PGF a promising electrode for the next-generation VFB, which can operate at high-power and all-climate conditions.
Hydrogen etching induced hierarchical meso/micro-pore structure with increased active density to boost ORR performance of Fe-N-C catalyst

Rational regulation on pore structure and active site density plays critical roles in enhancing the performance of Fe-N-C catalysts. As the microporous structure of the carbon substrate is generally regarded as the active site hosts, its hostility to electron/mass transfer could lead to the incomplete fulfillment of the catalytic activity. Besides, the formation of inactive metallic Fe particles during the conventional catalyst synthesis could also decrease the active site density and complicate the identification of real active site. Herein, we developed a facial hydrogen etching methodology to yield single site Fe-N-C catalysts featured with micro/mesoporous hierarchical structure. The hydrogen concentration in pyrolysis process was designated to effectively regulate the pore structure and active site density of the resulted catalysts. The optimized sample achieves excellent ORR catalytic performance with an ultralow H_2O_2 yield (1%) and superb stability over 10,000 cycles. Our finding provides new thoughts for the rational design of hierarchically porous carbon-based materials and highly promising non-precious metal ORR catalysts.
Preparation of nitrogen and sulfur co-doped ultrathin graphitic carbon via annealing bagasse lignin as potential electrocatalyst towards oxygen reduction reaction in alkaline and acid media

Renewable lignin used for synthesizing materials has been proven to be highly potential in specific electrochemistry. Here, we report a simple method to synthesize nitrogen and sulfur co-doped carbon nanosheets by using bagasse lignin, denoted as lignin-derived carbon (LC). By adjusting the ratio of nitrogen source and annealing temperature, we obtained the ultrathin graphitic lignin carbon (LC-4-1000) with abundant wrinkles with high surface area of 1208m~2g~(–1) and large pore volume of 1.40cm~3g~(–1). In alkaline medium, LC-4-1000 has more positive half-wave potential and nearly current density compared to commercial Pt/C for oxygen reduction reaction (ORR). More importantly, LC-4-1000 also exhibits comparable activity and superior stability for ORR in acid medium due to its high graphitic N ratio and a direct four electron pathway for ORR. This study develops a cost-effective and highly efficient method to prepare biocarbon catalyst for ORR in fuel cells.
Uranium sequestration in sediment at an iron-rich contaminated site at Oak Ridge, Tennessee via. bioreduction followed by reoxidation

This study evaluated uranium sequestration performance in iron-rich (30 g/kg) sediment via bioreduction followed by reoxidation. Field tests (1383 days) at Oak Ridge, Tennessee demonstrated that uranium contents in sediments increased after bioreduced sediments were re-exposed to nitrate and oxygen in contaminated groundwater. Bioreduction of contaminated sediments (1200 mg/kg U) with ethanol in microcosm reduced aqueous U from 0.37 to 0.023 mg/L. Aliquots of the bioreduced sediment were reoxidized with O_2, H_2O_2, and NaNO_3, respectively, over 285 days, resulting in aqueous U of 0.024, 1.58 and 14.4 mg/L at pH 6.30, 6.63 and 7.62, respectively. The source- and the three reoxidized sediments showed different desorption and adsorption behaviors of U, but all fit a Freundlich model. The adsorption capacities increased sharply at pH 4.5 to 5.5, plateaued at pH 5.5 to 7.0, then decreased sharply as pH increased from 7.0 to 8.0. The O_2-reoxidized sediment retained a lower desorption efficiency at pH over 6.0. The NO_3~– -reoxidized sediment exhibited higher adsorption capacity at pH 5.5 to 6.0. The pH-dependent adsorption onto Fe(III) oxides and formation of U coated particles and precipitates resulted in U sequestration, and bioreduction followed by reoxidation can enhance the U sequestration in sediment.
Aging-independent and size-dependent genotoxic response induced by titanium dioxide nanoparticles in mammalian cells

Titanium dioxide nanoparticles (TiO_2 NPs) are subjected to various transformation processes (chemical, physical and biological processes) in the environment, potentially affecting their bioavailability and toxic properties. However, the size variation of TiO_2 NPs during aging process and subsequent effects inmammalian cells are largely unknown. The aimof this study was to illustrate the adverse effects of TiO_2 NPs in different sizes (5, 15 and <100 nm) during aging process on human-hamster hybrid (A_L) cells. There was an aging-time dependent enhancement of average hydrodynamic size in TiO_2 NPs stock suspensions. The cytotoxicity of fresh TiO_2 NPs increased in a size-dependentmanner; in contrast, their genotoxicity decreased with the increasing sizes of NPs. No significant toxicity difference was observed in cells exposed to either fresh or 60 day-aged TiO_2 NPs. Both Fresh and aged TiO_2 NPs efficiently induced mitochondrial dysfunction and activated Caspase-3/7 in a size-dependent manner. Using mitochondrial-DNA deficient (ρ0) AL cells, we further discovered that mitochondrial dysfunction made significant contribution to the size-dependent toxicity induced by TiO_2 NPs during the aging process. Taken together, our data indicated that TiO_2 NPs could significantly induced the cytotoxicity and genotoxicity in an aging time-independent and size-dependent manner, which were triggered by mitochondrial dysfunction. Our study suggested the necessity to include size as an additional parameter for the cautious monitoring of TiO_2 NPs disposal before entering the environment.
植入式心电监测设备在儿童及青少年晕厥诊疗中的应用

目的评估植入式心电监测设备(insertable cardiac monitor,ICM)在儿童或青少年晕厥诊断中的价值及安全性。方法收集清华大学第一附属医院(北京华信医院)2016年5月至2017年12月5例[年龄(10.4±6.8)岁]植入ICM的病例,平均随访11个月。观察ICM植入在儿童或青少年病例中有无不良反应以及评估ICM对再发晕厥的诊断率。结果3例患儿在植入ICM后平均6个月出现了晕厥:1例晕厥时记录到多形性室性心动过速及2次窦性停搏,确诊为心源性晕厥,植入心律转复除颤器(implantable cardioverter defibrillation,ICD)。2例除外心源性晕厥。其余2例患儿随访过程无症状,ICM无心律失常记录,继续随访中。所有患儿随访期间,ICM植入无不良反应,包括囊袋感染、器械故障等。ICM诊断率为60%(3/5例)。结论ICM可安全有效地用于儿童及青少年晕厥的诊断及指导疾病进一步处理。
Bounds and constructions of optimal optical orthogonal codes with low correlation zone

Dear editor,In optical code division multiple access (CDMA) systems,optical orthogonal codes (OOC) should exhibit the following correlations to reduce multiple access interference:the non-trivial correlation between a sequence and its shift sequence and the correlation between sequence and shift sequence of other sequences should be as low as possible.Herein,the shift values of a sequence are randomly distributed throughout the sequence period.In quasi-synchronous CDMA systems,the time delay of the system is not very large and is generally distributed only in areas smaller than the sequence period.The purpose of reducing multiple access interference can be achieved using an address code that has a very small correlation function in the zone near zero.Therefore,a two-dimensional optical orthogonal code with zero cross-correlation zone is introduced.