mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
A 6–7 GHz, 40 dB receiver RF front-end with 4.5 dB minimum noise figure in 0.13 μm CMOS for IR-UWB applications

A wideband receiver RF front-end for IR-UWB applications is implemented in 0.13 μm CMOS technology. Thanks to the direct sub-sampling architecture, there is no mixing process. Both LNA and VGA work at RF frequencies. To optimize noise as well as linearity, a differential common-source LNA with capacitive crosscoupling is used, which only consumes current of 1.8 mA from a 1.2 V power supply. Following LNA, a two-stage current-steering VGA is adopted for gain tuning. To extend the overall bandwidth, a three-stage staggered peaking technique is used. Measurement results show that the proposed receiver front-end achieves a gain tuning range from 5 to 40 dB within 6–7 GHz, a minimum noise figure of 4.5 dB and a largest IIP_3 of –11 dBm. The core receiver (without test buffer) consumes 14 mW from a 1.2 V power supply and occupies 0.58 mm~2 area.
A novel switched capacitor bandgap reference with a correlated double sampling structure

A switched capacitor bandgap voltage reference with correlated double sampling structure embedded in a temperature sensor is implemented in a standard 0.35μm CMOS process.Due to the smaller change of the op-amp’s output voltage,this topology is very suitable for low power applications.In addition,errors caused by the finite op-amp gain,input offset voltage,and 1/f noise are eliminated with the correlated double sampling technique.Additionally,two-level process calibration techniques are designed to minimize the process spread. Finally,a method of getting a full period valid reference voltage output is discussed and experimental results are provided to verify the effectiveness of the proposed structure.
A low jitter PLL clock used for phase change memory

A fully integrated low-jitter,precise frequency CMOS phase-locked loop(PLL) clock for the phase change memory(PCM) drive circuit is presented.The design consists of a dynamic dual-reset phase frequency detector(PFD) with high frequency acquisition,a novel low jitter charge pump,a CMOS ring oscillator based voltage-controlled oscillator(VCO),a 2nd order passive loop filter,and a digital frequency divider.The design is fabricated in 0.35μm CMOS technology and consumes 20 mW from a supply voltage of 5 V.In terms of the PCM’s program operation requirement,the output frequency range is from 1 to 140 MHz.For the 140 MHz output frequency,the circuit features a cycle-to-cycle jitter of 28 ps RMS and 250 ps peak-to-peak.
Effect of junction temperature on the large-signal properties of a 94 GHz silicon based double-drift region impact avalanche transit time device

The authors have developed a large-signal simulation technique extending an in-house small-signal simulation code for analyzing a 94 GHz double-drift region impact avalanche transit time device based on silicon with a non-sinusoidal voltage excitation and studied the effect of junction temperature between 300 and 550 K on the large-signal characteristics of the device for both continuous wave(CW) and pulsed modes of operation.Results show that the large-signal RF power output of the device in both CW and pulsed modes increases with the increase of voltage modulation factor up to 60%,but decreases sharply with further increase of voltage modulation factor for a particular junction temperature;while the same parameter increases with the increase of junction temperature for a particular voltage modulation factor.Heat sinks made of copper and type-IIA diamond are designed to carry out the steady-state and transient thermal analysis of the device operating in CW and pulsed modes respectively. Authors have adopted Olson’s method to carry out the transient analysis of the device,which clearly establishes the superiority of type-IIA diamond over copper as the heat sink material of the device from the standpoint of the undesirable effect of frequency chirping due to thermal transients in the pulsed mode.
Color-stable, reduced efficiency roll-off hybrid white organic light emitting diodes with ultra high brightness

High-brightness and color-stable two-wavelength hybrid white organic light emitting diodes (HWOLEDs) with the configuration of indium tin oxide (ITO)/ N, N, N', N'-tetrakis(4-methoxyphenyl)-benzidine (MeOTPD): tetrafluoro-tetracyanoqino dimethane (F4-TCNQ)/N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (NPB)/4,4-N,N-dicarbazolebiphenyl (CBP): iridium (III) diazine complexes (MPPZ)_2Ir(acac)/NPB/2-methyl-9,10-di(2-naphthyl)anthracene (MADN): p-bis(p-N,N-di-phenyl-aminostyryl)benzene (DSA-ph)/ bis(10-hydroxybenzo[h] quinolinato) beryllium complex (Bebq_2)/LiF/Al have been fabricated and characterized. The optimal brightness of the device is 69932 cd/m~2 at a voltage of 13 V, and the Commission Internationale de l’Eclairage (CIE) chromaticity coordinates are almost constant during a large voltage change of 6-12 V. Furthermore, a current efficiency of 15.3 cd/A at an illumination-relevant brightness of 1000 cd/m~2 is obtained, which rolls off slightly to 13.0 cd/A at an ultra high brightness of 50000 cd/m~2. We attribute this great performance to wisely selecting an appropriate spacer together with effectively utilizing the combinations of exciton-harvested orange-phosphorescence/ blue-fluorescence in the device. Undoubtedly, this is one of the most exciting results in two-wavelength HWOLEDs up to now.
Diffusion dynamics in external noise-activated non-equilibrium open system reservoir coupling environment

The diffusion process in an external noise-activated non-equilibrium open system-reservoir coupling environment is studied by analytically solving the generalized Langevin equation. The dynamical property of the system near the barrier top is investigated in detail by numerically calculating the quantities such as mean diffusion path, invariance, barrier passing probability, and so on. It is found that, comparing with the unfavorable effect of internal fluctuations, the external noise activation is sometimes beneficial to the diffusion process. An optimal strength of external activation or correlation time of the internal fluctuation is expected for the diffusing particle to have a maximal probability to escape from the potential well.
Towards understanding the carbon trapping mechanism in copper by investigating the carbon-vacancy interaction

We propose a vacancy trapping mechanism for carbon-vacancy (C-V) complex formation in copper (Cu) according to the first-principles calculations of the energetics and kinetics of C-V interaction. Vacancy reduces charge density in its vicinity to induce C nucleation. A monovacancy is capable of trapping as many as four C atoms to form C_nV (n=1, 2, 3, 4) complexes. A single C atom prefers to interact with neighboring Cu at a vacancy with a trapping energy of -0.21 eV. With multiple C atoms added, they are preferred to bind with each other to form covalent-like bonds despite of the metallic Cu environment. For the C_nV complexes, C_2V is the major one due to its lowest average trapping energy (1.31 eV). Kinetically, the formation of the C_nV complexes can be ascribed to the vacancy mechanism due to the lower activation energy barrier and the larger diffusion coefficient of vacancy than those of the interstitial C.
An improved element-free Galerkin method for solving the generalized fifth-order Korteweg-de Vries equation

In this paper, an improved element-free Galerkin (IEFG) method is proposed to solve the generalized fifth-order Korteweg-de Vries (gfKdV) equation. When the traditional element-free Galerkin (EFG) method is used to solve such an equation, unstable or even wrong numerical solutions may be obtained due to the violation of the consistency conditions of the moving least-squares (MLS) shape functions. To solve this problem, the EFG method is improved by employing the improved moving least-squares (IMLS) approximation based on the shifted polynomial basis functions. The effectiveness of the IEFG method for the gfKdV equation is investigated by using some numerical examples. Meanwhile, the motion of single solitary wave and the interaction of two solitons are simulated using the IEFG method.
Experimental research on the residual magnetization of a rare-earth permanent magnet for a cryogenic undulator

The magnetic properties of commercial polycrystalline Nd_2Fe_(14)B (N50M, N45H, N40SH, N35EH) and Sm_2Co_(17) (XG30/20, XG26/25, XG22/20) magnets at cryogenic temperatures were tested by using a comprehensive physical properties measurement system (PPMS). The results show that the spin tilt temperature T_(st) of Nd_2Fe_(14)B magnets is closely related to intrinsic coercivity H_(ci), N50M and N45H with smaller H_(ci) show a residual magnetization jump at 235 K and 225 K, respectively. For Sm_2Co_(17) magnets, in 50-300 K, with temperature decreasing, residual magnetization M_(rc) shows a nearly linear increase, while in 10-50 K, M_(rc) has little change. The research results provide a reference for cryogenic undulators and other high-precision cryogenic devices.
Triple-differential cross section for single ionization of H_2 by electron impact

The triple-differential cross section (TDCS) for the (e, 2e) ionization of a hydrogen molecule is calculated using the molecule distorted-wave Born approximation (MDWBA). Distorted waves are obtained by solving momentum-space coupled-channel Lippmann-Schwinger equations, including the ground state and the lowest-lying electronic state of b~3Σ_u. TDCSs at the incident energy 100 eV in coplanar asymmetric geometry are reported. The present calculations are compared with the available experimental measurements and the theoretical results.
Effect of Phenylephrine on Alveolar Fluid Clearance in Ventilator-induced Lung Injury

Objective To investigate the effect of phenylephrine(an α-adrenergic agonist) on alveolar fluid clearance(AFC) in ventilator-induced lung injury and the possible mechanism involved.Methods A total of 170 male Wistar rats were randomly allocated into 17 groups(n=10) using random number tables.Short-term(40 minutes) mechanical ventilation with high tidal volume(HVT) was performed to induce lung injury,impair active Na~+ transport and lung liquid clearance in the rats.Unventilated rats served as controls.To demonstrate the effect of phenylephrine on AFC,phenylephrine at different concentrations(1×10~(-5),1×10~(-6),1×10~(-7),1×10~(-8),and 1×10~(-9) mol/L) was injected into the alveolar space of the HVT ventilated rats.To identify the influence of adrenergic antagonists,Na~+ channel,and microtubular system on the effect of phenylephrine,phenylephrine at 1×10~(-5) mol/L combined with prazosin(an α_1-adrenergic antagonist,1×10~(-4) mol/L),yohimbine(an α_2-adrenergic antagonist,1×10~(-4) mol/L),atenolol(a β_1 adrenergic antagonist,1×10~(-5) mol/L),ICI-118551(an β_2-adrenergic antagonist,1×10~(-5) mol/L),amiloride(a Na~+ channel blocker,5×10~(-4) mol/L),ouabain(a Na~+ /K~+-ATPase blocker,5×10~(-4) mol/L),colchicine(a microtubular disrupting agent,0.25 mg/100 g body weight),or β-lumicolchicine(an isomer of colchicine,0.25 mg/100 g body weight) were perfused into the alveolar space of the rats ventilated with HVT for 40 minutes.AFC and total lung water content were measured.Results Basal AFC in control rats was(17.47±2.56)%/hour,which decreased to(9.64± 1.32)%/hour in HVT ventilated rats(P=0.003).The perfusion of phenylephrine at 1×10~(-8),1×10~(-7),1×10~(-6),and 1×10~(-5) mol/L significantly increased the AFC in HVT ventilated rats(all P<0.05).This effect of phenylephrine on AFC was suppressed by prazosin,atenolol,and ICI-118551 in HVT ventilated rats by 53%,31%,and 37%,respectively(all P<0.05).The AFC-stimulating effect of phenylephrine was lowered by 33% and 42% with amiloride and ouabain,respectively(both P<0.05).Colchicine significantly inhibited the effect of phenylephrine(P=0.031).Conclusion Phenylephrine could increase the AFC in HVT-ventilated rats and accelerate the absorption of pulmonary edema.
Breast Milk Lead and Cadmium Levels in Suburban Areas of Nanjing,China

Objective To evaluate levels of lead(Pb) and cadmium(Cd) in the breast milk in the second postpartum month,to investigate the relationship between Pb/Cd levels in breast milk and some sociodemographic parameters,and to explore whether these levels affect the infants’ physical status or the mothers’ psychological status(postpartum depression).Methods A cross-sectional study was conducted between November 2009 and December 2010.Altogether 170 healthy mothers were enrolled from Nanjing Maternity and Child Health Care Hospital.The inclusion criteria were:voluntary to participate in this study,healthy,with no chronic disease,breastfeeding in the second postpartum month,living in a suburban but not non-industrial area of Nanjing,and not occupationally exposed to toxic metals.All the mothers completed a questionnaire and were evaluated based on the Edinburgh Postpartum Depression Scale(EPDS) to identify the risk of postpartum depression.Pb and Cd levels in breast milk were determined by inductively coupled plasma mass spectroscopy.The infants of these mothers were examined for their z scores of weight for age,length for age,head circumference for age,and body mass index for age.Results The median breast milk levels of Pb and Cd were 40.6 μg/L and 0.67 μg/L,respectively.In 164(96.5%) of the 170 samples,Pb levels were higher than the limit reported by the World Health Organization(> 5 μg/L).Breast milk Cd level was > 1 μg/L in 54(31.8%) mothers.The mothers with a history of anemia had a higher breast milk Pb level than those without a history of anemia(41.1 μg/L vs.37.9 μg/L,P = 0.050).The median breast milk Cd level in those who were active and passive smokers during pregnancy was significantly higher than that in non-smokers(0.88 μg/L vs.0.00 μg/L,P = 0.025).The breast milk Cd level in the mothers not taking iron and vitamin supplements for 2 months postpartum was higher than in those taking the supplements(iron supplement:0.74 μg/L vs.0.00 μg/L,P = 0.025;vitamin supplement:0.78 μg/L vs.0.00 μg/L,P = 0.005).Breast milk Cd level at the second postpartum month was negatively correlated with the z scores of head circumference(r = 0.248,P = 0.042) and weight for age at birth(r = 0.241,P = 0.024) in girls.No correlation was found between the breast milk Pb/Cd levels and the EPDS scores.Conclusion Considering the high levels of Pb and Cd in breast milk in this study,breast milk monitoring programs are necessary.
辽宁锡伯族群体15个STR基因座遗传多态性

本文应用Goldeneye~(TM)16A系统对辽宁锡伯族人群15个STR基因座进行遗传多态性调查,为法医学个体识别、亲权鉴定以及群体遗传学研究等提供基础资料。
丘脑前核电刺激治疗癫痫

癫痫是一种严重威胁人类健康的慢性神经系统疾病,世界卫生组织统计表明,世界上约有5000万癫痫患者,在我国就有900万癫痫患者,其中约有20%~30%为药物难治性癫痫,需要进行手术干预。但对于无法行致痫灶切除手术的顽固性癫痫,应用现有的治疗手段仍无法完全控制其发作。近十几年来,脑深部电刺激(deep brain stimulation,DBS)术在治疗运动障碍性疾病中的良好疗效及其微侵袭性、可逆性、安全性等优点,使其在治疗癫痫等其他神经系统疾病中的作用越来越受到重视。大量的动物实验和临床研究证实丘脑前核(anterior nucleus of thalamic, ANT)电刺激在癫痫的治疗方面具有良好的应用前景。
中国脑积水规范化治疗专家共识(2013版)

颅内蛛网膜下腔或脑室内的脑脊液异常积聚,使其一部分或全部异常扩大称为脑积水。单纯脑室扩大者称为脑内积水,单纯颅内蛛网膜下腔扩大者称为脑外积水。脑积水不是一种单一的疾病改变,而是诸多病理原因引起的脑脊液循环障碍。脑积水是由脑脊液循环障碍(通道阻塞),脑脊液吸收障碍,脑脊液分泌过多,脑实质萎缩等原因造成。临床中最常见的是梗阻性病因,如脑室系统不同部位(室间孔、导水管、正中孔)的阻塞、脑室系统相邻部位的占位病变压迫和中枢神经系统先天畸形。按流体动力学分为交通性和梗阻性脑积水;按时限进展分为先天性和后天性脑积水,急性和慢性脑积水,进行性和静止性脑积水;按影像学分为单纯性、继发性和代偿性脑积水;按病理生理分为高压力性、正常压力性、脑萎缩性脑积水;按年龄分为儿童和成人脑积水。
颅内外沟通性Rosai-Dorfman病一例并文献复习

Rosai-Dorfman病(Rosai-Dorfman disease, RDD)是一种良性自限性罕见病,以窦组织细胞增生伴淋巴结肿大为特征,病因不明,累及中枢神经系统的 RDD十分罕见。本文报告1例颅内外沟通性 RDD,并进行文献复习。
periostin与肿瘤相关研究进展

periostin是在鼠成骨细胞株中发现的一种促成骨细胞形成黏附蛋白,对维持骨及牙齿组织,以及心肌发育、损伤后修复有调节作用。近来研究结果提示periostin与肿瘤也有密切关系,特别是在肿瘤微环境形成及肿瘤侵袭转移中扮演了重要的角色。本文就periostin在肿瘤中的研究进展作一综述。
细胞因子和骨髓移植在急性放射病救治中的应用

随着核工业的迅速发展与核技术的广泛应用, 意外放射事故时有发生, 多数散发, 有时亦为大规模严重事故, 导致急性放射病(ARS)的发生。ARS是指机体一次性或短时间内分次受到大剂量射线照射引起的全身系统性疾病。根据照射剂量的不同分为骨髓型、肠型和脑型, 其中肠型和脑型的死亡率极高, 而骨髓型则是目前临床救治的重点。骨髓型ARS主要表现为造血功能和免疫功能损伤及相关合并症, 照射剂量小于7Gy的患者可用细胞因子联合治疗, 7~10Gy患者还需要造血干细胞移植的介入。目前ARS患者移植主要参考了白血病等恶性肿瘤的移植模式, 绝大多数患者虽可达短期植入, 但尚无长期存活病例。由于ARS患者临床较少见, 多数研究集中在ARS动物模型中。同时肿瘤患者高剂量放化疗后的救治经验也可以为ARS的救治提供临床依据。近年来, 新的细胞因子如角质细胞生长因子(KGF)及新型干细胞如间充质干细胞(MSC)的使用提高了患者生存率, 但MSC临床应用尚缺乏经验。本专题对细胞因子应用的时机、剂量、疗程进行探讨。
全身麻醉药及围术期因素对发育中大脑神经认知功能的影响

人们关注全身麻醉药是否影响婴幼儿发育中的大脑是在其临床应用1个世纪后。1953年有文献报道在氯乙烷吸入麻醉下行耳鼻喉手术后儿童发生了长时间的人格改变,随后的一些动物实验证实,氟烷在妊娠大鼠中慢性暴露可以导致仔代神经突触发生延迟及行为异常。1999年Olney实验室研究证实应用氯胺酮可导致新生大鼠脑组织广泛的神经退行性变,类似胎儿酒精综合征的脑部表现。随后的研究相继证实其他常用麻醉药物如氧化亚氮(N_2O)、异氟烷等均可造成动物大脑神经细胞死亡,其中临床麻醉中常用的“鸡尾酒麻醉”即联合应用不同全身麻醉药,除引起新生动物即时的神经组织结构异常外,还会造成其成年后的大脑神经元密度降低和长期认知功能削弱,啮齿类新生动物对这种神经退化作用尤为敏感。
Crystal structures and biochemical studies of human lysophosphatidic acid phosphatase type 6

Lysophosphatidic acid (LPA) is an important bioactive phospholipid involved in cell signaling through Gprotein-coupled receptors pathways. It is also involved in balancing the lipid composition inside the cell, and modulates the function of lipid rafts as an intermediate in phospholipid metabolism. Because of its involvement in these important processes, LPA degradation needs to be regulated as precisely as its production. Lysophosphatidic acid phosphatase type 6 (ACP6) is an LPA-specific acid phosphatase that hydrolyzes LPA to monoacylglycerol (MAG) and phosphate. Here, we report three crystal structures of human ACP6 in complex with malonate, L-(+)-tartrate and tris, respectively. Our analyses revealed that ACP6 possesses a highly conserved Rossmann-foldlike body domain as well as a less conserved cap domain. The vast hydrophobic substrate-binding pocket, which is located between those two domains, is suitable for accommodating LPA, and its shape is different from that of other histidine acid phosphatases, a fact that is consistent with the observed difference in substrate preferences. Our analysis of the binding of three molecules in the active site reveals the involvement of six conserved and crucial residues in binding of the LPA phosphate group and its catalysis. The structure also indicates a water-supplying channel for substrate hydrolysis. Our structural data are consistent with the fact that the enzyme is active as a monomer. In combination with additional mutagenesis and enzyme activity studies, our structural data provide important insights into substrate recognition and the mechanism for catalytic activity of ACP6.
Co-evolution of plant LTR-retrotransposons and their host genomes

Transposable elements (TEs), particularly, long terminal repeat retrotransposons (LTR-RTs), are the most abundant DNA components in all plant species that have been investigated, and are largely responsible for plant genome size variation. Although plant genomes have experienced periodic proliferation and/or recent burst of LTR-retrotransposons, the majority of LTR-RTs are inactivated by DNA methylation and small RNA-mediated silencing mechanisms, and/or were deleted/truncated by unequal homologous recombination and illegitimate recombination, as suppression mechanisms that counteract genome expansion caused by LTR-RT amplification. LTR-RT DNA is generally enriched in pericentromeric regions of the host genomes, which appears to be the outcomes of preferential insertions of LTR-RTs in these regions and low effectiveness of selection that purges LTR-RT DNA from these regions relative to chromosomal arms. Potential functions of various TEs in their host genomes remain blurry; nevertheless, LTR-RTs have been recognized to play important roles in maintaining chromatin structures and centromere functions and regulation of gene expressions in their host genomes.
太阳风动压脉冲条件下电离层与等离子体层的物质输运

行星际条件如何影响等离子体层和电离层之间的物质传输至今还是一个悬而未决的问题.我国刚建成的子午工程可以对等离子体层和电离层开展同时监测,为了解这两个区域之间等离子体的传输特性和耦合机制提供了新的机遇.我们分析了2011年3月21~27日地磁平静期间等离子体层(L≈2)与电离层物质输运对太阳风脉冲的响应,发现地磁平静时期等离子体层在太阳风动压脉冲作用下出现削减.在太阳风动压脉冲作用下,等离子体层密度减少至动压脉冲前的一半,而后经过1~2d逐渐恢复至初始水平;同时,电离层F2层最大电子密度(NmF2)和电离层总电子密度含量(TEC)增加13%和21%,而后恢复至初始值,这与磁暴期间的表现是相反的.初步的分析表明:在该事件中,太阳风动压脉冲之后的行星际南向磁场和变化较大的晨昏电场可能是导致等离子体层密度减少的主要原因,变化的行星际条件和电离层共同控制着等离子体层的密度变化.
新型壳聚糖纳米氧化铁磁珠的制备和理化性能测定

目的研制一种新型壳聚糖纳米氧化铁磁珠,并检测其理化性质,为更加优化的免疫磁珠技术奠定基础。方法采用凝聚沉淀的方法,通过在纳米氧化铁磁珠表面包被一层壳聚糖分子,制备出壳聚糖纳米氧化铁磁珠。并对磁珠的粒径大小、显微特征、壳聚糖外壳和磁珠内核的关系以及壳聚糖磁珠的理化性能进行检测、分析。结果制作过程简便、易行,制作出的壳聚糖纳米氧化铁磁珠粒径均匀,成球性与稳定性好。结论成功制备了新型纳米壳聚糖氧化铁磁珠,为靶向药物载体、细胞分离、核酸提取等应用提供了实验材料。
mRNA疫苗研究进展

mRNA疫苗是具有免疫性、安全性及灵活性的基因疫苗。相比传统疫苗,mRNA疫苗能够刺激免疫系统产生平衡、长效的保护;被以Toll样受体为主的受体识别,进入细胞,在胞液中表达,通过刺激免疫系统产生B、T细胞等多种机制,达到预防流行病及抗肿瘤等作用。部分mRNA疫苗本身具有的疫苗佐剂特性,通过产生多种细胞因子等不同方式刺激免疫系统,增强免疫机体反应能力,缩短免疫应答时间,加大抗体合成释放能力,在新型疫苗制备具有极大的应用价值。本文系统介绍了mRNA疫苗的组成、研究进展及其优势。
祁山药芦头种苗质量分级的研究

对安国药材种苗市场30批次祁山药芦头的净度、纯度、含水量、长度、直径、单株重、出苗率等指标进行测定,应用SPSS19.0分析软件进行K-中心聚类分析,将祁山药芦头种苗分为三级,对祁山药芦头种苗质量分级和规范其种苗市场具有指导作用。
引发处理对白皮松种子发芽及生理的影响

该试验以白皮松种子为对象,进行水引发以及渗透势为-0.3、-0.6和-1.2MPa的KNO_3溶液引发处理(未引发干种子为对照),通过对种子发芽及生理指标的测定,研究了水引发及渗透引发对白皮松种子萌发及生理的影响。结果表明:与对照相比,不同引发处理均显著提高了白皮松种子的发芽率、发芽指数,缩短了平均发芽时间,降低了相对电导率和丙二醛含量,但综合各项指标发现,-0.3 MPa KNO_3溶液引发处理,白皮松种子发芽率、发芽指数最大,发芽速度最快,且对细胞膜修复效果最佳。
血浆甲基化SEPT9 DNA用于筛查无症状结直肠癌

美国学者Church等对精确检测血浆中甲基化SEPT9 DNA(mSEPT9)筛查人群中结直肠患者的方法进行了前瞻性的评价。该研究选取年龄≥50岁、无临床症状的人群进行结肠镜筛查,检査前留取血浆样本,由3个设盲的独立实验室采用RT-PCR分析所有检出的结直肠癌患者和随机分层的其他筛査者血浆的DNA,并对总体的灵敏度和特异性进行标准化。研究结果显示:对53例结直肠癌和1 457例无结直肠癌的研究对象,该方法的标准化灵敏度为48.2%(95%可信区间32.4%~63.6%,粗略灵敏度为50.9%);对于I ~IV期结直肠癌患者分别为35.0%、63.0%、46.0%和77.4%。特异性为91.5%(95%可信区间89.7%~ 93.1%,粗略特异性为91.4%)。对进展期腺瘤的灵敏度低(11.2%)。研究结果表明通过检测血浆中甲基化SEPT9 DNA可以发现结直肠癌在血液中的信号,可用于对结直肠癌的中危个体进行筛查,但对结直肠癌的群体筛査仍有待提高该检测方法对早期结直肠癌和进展期腺瘤的灵敏度。
全胸腔镜下肺癌微创手术——肺癌手术的发展趋势

上世纪九十年代初开始,随着电视胸腔镜的出现和影像成像等技术的快速发展,胸部微创外科技术步入了快速发展通道,微创手术范围不断扩大,医患群体的认可和接受程度逐年增高。二十年后的今天,胸腔镜微创手术已日益成为胸外科临床上应用最广的手术方式,毫无疑问,胸腔镜微创手术是胸外科界革命性的里程碑式的进步!与此同时,胸腔镜下肺癌微创手术技术亦在不断发展,时至今日,胸腔镜手术中相对难度最高的全胸腔镜下肺癌微创手术亦得到世界范围内的公认和推荐,可能是目前最佳的肺癌微创手术方式。
The Effects of SF_6-Cu Mixture on the Arc Characteristics in a Medium Voltage Puffer Gas Circuit Breaker due to Variation of Thermodynamic Properties and Transport Coefficients

In a gas circuit breaker, metal vapor resulting from electrode erosion is injected into the arc plasma. The arc then burns in a mixture of SF_6 and electrode vapor, which has properties significantly different from those of pure SF_6. Thermodynamic properties and transport coefficients of thermal plasmas formed in SF_6-copper vapor mixtures change as a function of temperature and pressure. The property that is mostly affected by the presence of copper is electrical conductivity, which is important in magnetohydrodynamic (MHD) analysis. In this study, the transport coefficients of SF_6 in the presence of 10 percent copper are considered as the basis of MHD simulation. Comparisons are made between the results during arc formation for pure SF_6 and SF_6-Cu mixture in a medium voltage (MV) circuit breaker. According to the transport coefficients influenced by the SF_6-Cu mixture, the distribution of the electric potential, temperature, electromagnetic force density and current density of the arc column are presented and discussed. Also, the arc stability and pinch effect near current zero with 3-D simulation are investigated, which is advantageous to improving the efficiency of arc plasma simulation.
High-Density Polyethylene (HDPE) Surface Treatment Using an RF Capacitive Atmospheric Pressure Cold Ar Plasma Jet

In this study, a high-density polyethylene (HDPE, 5-mm-thick, 0.95 g/cm~3) surface was treated using an RF capacitive atmospheric pressure cold Ar plasma jet. By using this Ar plasma jet, a hydrophilic HDPE surface was formed during the plasma treatment. In particular, the effects of an additive gas (N_2 or O_2) on the HDPE surface treatment were investigated in detail. It was shown that the addition of N_2 or O_2 gas had an important influence on the HDPE surface treatment. Compared to pure Ar plasma treatment, a lower value of water contact angle (WCA) was obtained when a trace of N_2 or O_2 gas was added. It was also found that besides the quantities of active species in the plasma jet, the treatment temperature played an important role in the HDPE surface treatment. This is because surface molecular motion is not negligible when the treatment temperature is close to the melting point of the polymer.