先天性感音神经性耳聋患儿的HRCT耳蜗定量参数与听觉传导通路DTI参数的相关性

本研究探讨分析先天性感音神经性耳聋(CSNHL)患儿高分辨率CT(HRCT)定量参数与听觉传导通路磁共振弥散张量成像(DTI)参数的关系。选取CSNHL患儿62例作为观察组,同时选取听力正常患儿50例作为对照组,分析各组HRCT、DTI参数差异。实验结果显示:观察组蜗神经管长度和宽度、耳蜗高度明显低于对照组(P<0.05);观察组颞横回、颞上回、内囊后肢、听辐射和上橄榄核各向异性分数(FA)值明显低于对照组(P<0.05),表观弥散系数(ADC)值明显高于对照组(P<0.05);观察组轻度患儿蜗神经管长度、蜗神经管宽度及耳蜗高度、听辐射FA值明显高于中重度、极重度患儿(P<0.05),ADC值明显低于中重度、极重度患儿(P<0.05);蜗神经管长度、蜗神经管宽度及耳蜗高度与听辐射FA值呈正相关(P<0.05),与听辐射ADC值呈负相关(P<0.05)。研究证实:不同严重程度CSNHL患儿HRCT参数蜗神经管长度、蜗神经管宽度及耳蜗高度与听辐射FA、ADC有一定相关性。

陈日新“消敏定量”悬灸学术思想及其临床应用

灸量即艾灸的每次有效作用剂量,是艾灸疗效的关键影响因素之一。本文从古代医家对灸量的认识、现代常用灸量标准、灸量新标准——"消敏定量"、临床应用及体会五个方面论述了陈日新教授"消敏定量"悬灸学术思想及其临床应用情况。结果表明"消敏定量"的艾灸定量标准操作简便、临床可操作性强,值得临床应用与推广。

HPLC法同时测定速感宁片中2种化学组分的含量

目的:建立HPLC法并同时测定速感宁片中对乙酰氨基酚和马来酸氯苯那敏含量的方法。方法:采用Nucleodur C18 Gravity(4.6mm×250mm,5μm)色谱柱,流动相为0.05mol/L磷酸二氢铵-乙腈梯度洗脱;检测波长为262nm,流速为1.0mL/min,柱温为室温。结果:对乙酰氨基酚进样量在4.09～36.78μg范围内与峰面积呈良好线性关系(r=0.9991),平均回收率为100.5%,RSD=1.92%(n=5);马来酸氯苯那敏进样量在0.05～0.43μg范围内与峰面积呈良好线性关系(r=0.999 9),平均回收率为98.27%,RSD=1.57%(n=5)。结论:该方法简便快速,其他成分无干扰,适用于速感宁片中2种化学组分的同时测定。

X线CT研究与发展之展望

在过去十年中,CT理论、技术与应用经历了快速的发展。鉴于CT的实用性,无疑,CT技术将继续推动生物医学应用和非生物医学应用。在这篇展望中,发表关于CT研究与开发的若干观点,着重提出未来十年内关键性的12个论题,它们是:解析重建、迭代重建、局部/内重建、基于平板检测器的CT、双源CT、多源CT、新扫描模式、能(量)敏(感)CT、纳米CT、伪影消除、模式融合和相衬CT等。文中还列出了CT的若干典型生物医学应用。

Developmental Changes of the FAS and HSL mRNA Expression and Their Effects on the Content of Intramuscular Fat in Kazak and Xinjiang Sheep

Twenty-four male Kazak sheep and 30 Xinjiang fine wool sheep at different ages were selected to investigate the development-dependent expression levels of fatty acid synthase （FAS） gene and hormone-sensitive lipase （HSL） gene in muscle and their effects on the contents of intramuscular fat （IMF）. Longissimus dorsal muscle was sampled to measure IMF and total RNA was extracted to determine FAS and HSL mRNA expression levels by real-time PCR. The results showed that： l） The IMF content increased continuously with growth and showed significant differences （P 〈 0.05） between different age groups in male Kazak sheep, but in Xinjiang fine wool sheep there was no such difference observed. Furthermore, the IMF contents in Kazak were much higher （P 〈 0.01） than that of the other breed from day 30 to 90. 2） FAS mRNA expression level was the highest （P 〈 0.05） on day 0 in Kazak sheep and then declined with growth, in the other breed the gene showed a d‘ecline-rise-decline-rise＇ expression manner as the animals grew. HSL mRNA expression level had a similar model in two breeds, in Kazak sheep it was the highest on day 0 （P 〈 0.05） and in Xinjiang fine wool sheep on day 30 （P 〈 0.01）, then both decreased after this term. 3） In male Kazak sheep, FAS and HSL mRNA expression level were both negatively related to IMF content （r= -0.485 （P = 0.02）, r= -0.423 （P = 0.05））, and the ratio of FAS/HSL expression exhibited significantly negatively related IMF contents. In male Xinjiang sheep, there were no obvious relationship between FAS and HSL expression and IMF content （P 〉 0.05）.

Electromagnetic holographic sensitivity field of two-phase flow in horizontal wells

Electromagnetic holographic data are characterized by two modes, suggesting that image reconstruction requires a dual-mode sensitivity field as well. We analyze an electromagnetic holographic field based on tomography theory and Radon inverse transform to derive the expression of the electromagnetic holographic sensitivity field （EMHSF）. Then, we apply the EMHSF calculated by using finite-element methods to flow simulations and holographic imaging. The results suggest that the EMHSF based on the partial derivative of radius of the complex electric potential φ is closely linked to the Radon inverse transform and encompasses the sensitivities of the amplitude and phase data. The flow images obtained with inversion using EMHSF better agree with the actual flow patterns. The EMHSF overcomes the limitations of traditional single-mode sensitivity fields.

Application of support vector machine in trip chaining pattern recognition and analysis of explanatory variable effects

In order to improve the accuracy of travel demand forecast and considering the distribution of travel behaviors within time dimension, a trip chaining pattern recognition model was established based on activity purposes by applying three methods： the support vector machine （SVM） model, the radial basis function neural network （RBFNN） model and the multinomial logit （MNL） model. The effect of explanatory factors on trip chaining behaviors and their contribution to model performace were investigated by sensitivity analysis. Results show that the SVM model has a better performance than the RBFNN model and the MNL model due to its higher overall and partial accuracy, indicating its recognition advantage under a smai sample size scenario. It is also proved that the SVM model is capable of estimating the effect of multi-category factors on trip chaining behaviors more accurately. The different contribution of explanatory, factors to trip chaining pattern recognition reflects the importance of refining trip chaining patterns ad exploring factors that are specific to each pattern. It is shown that the SVM technology in travel demand forecast modeling and analysis of explanatory variable effects is practical.

CT无阳性表现的轻度脑损伤患者SWI的应用价值

目的观察CT无阳性表现的轻度脑损伤患者SWI的应用价值。方法对180例轻度脑损伤患者的脑CT和脑MRI资料进行分析,根据有或无异常脑MRI表现将无阳性CT表现患者分为2组,对影像资料进行评价。结果无阳性CT表现的轻度脑损伤患者18例(10.0%)有颅脑损伤表现,最多见的症状为头痛(51.7%)。MRI显示颅脑损伤部位包括颞极区(n=8)、额极(n=5)、大脑镰(n=2)、基底节(n=1)、小脑幕(n=1)和外侧裂(n=1)。颅脑损伤多见于意识丧失、症状时间>2周或线性颅骨骨折患者(P=0.000 13)。结论轻度脑损伤无阳性CT表现患者少数可有颅脑损伤,提示即使经CT扫描无异常表现的轻度脑损伤患者亦需进一步检查,包括MRI扫描。

Respiratory Virus Multiplex RT-PCR Assay Sensitivities and Influence Factors in Hospitalized Children with Lower Respiratory Tract Infections

Multiplex RT-PCR assays have been widely used tools for detection and differentiation of a panel of respiratory viral pathogens. In this study, we evaluated the Qiagen ResPlex lI V2.0 kit and explored factors influencing its sensitivity. Nasopharyngeal swab （NPS） specimens were prospectively collected from pediatric inpatients with lower respiratory tract infections at the time of admission in the Shenzhen Children＇s Hospital from May 2009 to April 2010. Total nucleic acids were extracted using the EZ1 system （Qiagen, Germany） and 17 respiratory viruses and genotypes including influenza A virus （FluA）, FluB, parainfluenza virus 1 （PIV1）, PIV2, PIV3, PIV4, respiratory syncytial virus （RSV）, human metapneumovirus （hMPV）, rhinoviruses （RhV）, enteroviruses （EnV）, human bocaviruses （hBoV）, adenoviruses （AdV）, four coronaviruses （229E, OC43, NL63 and HKU1）, and FluA 2009 pandemic H1NI（H1NI-p） were detected and identified by the ResPlex II kit. In parallel, 16 real-time TaqMan quantitative RT-PCR assays were used to quantitatively detect each virus except for RhV. Influenza and parainfluenza viral cultures were also performed. Among the total 438 NPS specimens collected during the study period, one or more viral pathogens were detected in 274 （62.6%） and 201（45.9%） specimens by monoplex TaqMan RT-PCR and multiplex ResPlex, respectively. When results from monoplex PCR or cell culture were used as the reference standard, the multiplex PCR possessed specificities of 92.9-100.0%. The sensitivity of multiplex PCR for PIV3, hMPV, PIV1 and BoV were 73.1%, 70%, 66.7% and 55.6%, respectively, while low sensitivities （11.1%-40.0%） were observed for FluA, EnV, OC43, RSV and H1N1. Among the seven viruses/genotypes detected with higher frequencies, multiplex PCR sensitivities were correlated significantly with viral loads determined by the TaqMan RT-PCR in FluA, H 1N 1-p and RSV （p=0.011-0.000） The Qiagen ResPlex II multiplex RT-PCR kit possesses excellent specificity for simultaneous detection of 17 viral pathogens in NPS specimens in pediatric inpatients at the time of admission. The sensitivity of multiplex RT-PCR was influenced by viral loads, specimen process methods, primer and probe design and amplification condition.

A Rapid and Sensitive One Step-SYBR Green Based Semi Quantitative Real Time RT-PCR for the Detection of peste des petits ruminants Virus in the Clinical Samples

A sensitive and rapid single step real time （rt） RT-PCR was standardized using one-step Brilliant SYBR Green kit for detection and semi-quantitation ofpeste des petitis ruminants virus （PPRV） using the virus RNA and matrix （M） protein gene-specific primers and compared with established conventional RT-PCR and TaqMan RT-PCR. The assay amplifies a 124 bp fragment of the PPRV M gene with Tm of 78.28 to 78.50. The assay was linear within a range of 50 ng to 0.5 fg total virus RNA with a detection limit （sensitivity） of 0.5 fg. Based on the serial dilution of the live-attenuated PPR vaccine virus, the detection limit was -0.0001 cell culture infectious dose 50% units （TCID50）. Additionally, swab materials spiked with known titre of vaccine virus were equally well detected in the assay. The standardized rt RT-PCR was easily employed for the detection of PPRV nucleic acid directly in the field and experimental clinical samples. The assay detected the PPRV nucleic acid as early as 3 day post infection （dpi） and up to 20 dpi in swab materials from the experimental samples. The assay was rapid and more sensitive than TaqMan and conventional RT-PCR in the detection of PPRV nucleic acid from the PPR suspected clinical samples of sheep and goats. Therefore, the established, simplified SYBR green rt RT-PCR is an alternative test to the already existing various diagnostic assays and could be useful for rapid clinical diagnosis with advantage in reducing risk of contamination.

Effect of Si,Cu and Fe on mechanical properties of cast semi-solid 206 alloys

The development of a modified 206 alloy whose composition was optimized to minimize hot tearing during semi-solid forming was reported. The effect of varying silicon, copper and iron contents was investigated using a design of experiment (DOE) approach. Semi-solid slurries were prepared using the SEED process and injected into a high pressure die casting press. The hot tearing sensitivity results were reported for different alloy variants. The microstructure evolution during the semi-solid preparation was presented along with actual die cast components. The effects of silicon, copper and iron on mechanical properties in the T7 condition were also analyzed. Beyond the benefit of reducing hot tearing, it is shown that the tensile and fatigue properties remain compatible with the automotive industry requirements.

Analysis and Measurement of Mass Transfer in Airlift Loop Reactors

Inter-phase mass transfer is important to the design and performance of airlift loop reactors for either chemical or biochemical applications, and a good measurement technique is crucial for studying mass transfer in multiphase systems. According to the model of macro-scale mass transfer in airlift loop reactors, it was proved that the airlift loop reactor can be regarded as a continuous stirred tank reactor for measuring mass transfer coefficient. The calculated mass transfer coefficient on such a basis is different from the volumetric mass transfer coefficient in the macro-scale model and the difference is discussed. To describe the time delay of the probe response to the change of oxygen concentration in the liquid phase, a model taking into account the time constant of response is es-tablished. Sensitivity analysis shows that this model can be used to measure the volumetric mass transfer coefficient. Applying this model to the measurement of volumetric mass transfer coefficient in the loop reactor, results that co-incide with the turbulence theory in the literate were obtained.

Quantitative Estimation on Contributions of Climate Changes and Human Activities to Decreasing Runoff in Weihe River Basin, China

Human activities and climate changes are deemed to be two primary driving factors influencing the changes of hydrological processes, and quantitatively separating their influences on runoff changes will be of great significance to regional water resources planning and management. In this study, the impact of climate changes and human activities was initially qualitatively distinguished through a coupled water and energy budgets analysis, and then this effect was further separated by means of a quantitative estimation based on hydrological sensitivity analysis. The results show that: 1) precipitation, wind speed, potential evapotranspiration and runoff have a significantly decreasing trend, while temperature has a remarkably increasing tendency in the Weihe River Basin, China; 2) the major driving factor on runoff decrease in the 1970 s and 1990 s in the basin is climate changes compared with that in the baseline 1960 s, while that in the 1980 s and 2000 s is human activities. Compared with the results based on Variable Infiltration Capacity(VIC) model, the contributions calculated in this study have certain reliability. The results are of great significance to local water resources planning and management.

Conception of tooling adapted to thixoforging of high solid fraction hot-crack-sensitive aluminium alloys

Thixoforging is a type of semi-solid metal processing at high solid fraction (0.7<φs<1), which involves the processing of alloys in the semi-solid state.Tooling has to be adapted to this particular process to benefit shear thinning and thixotropic behaviour of such semi-solid material.Tooling parameters, such as the forming speed and tool temperature, have to be accurately controlled because of their influence on thermal exchanges between material flow and tool.These thermal exchanges influence the high-cracking tendency and the rheology of the semi-solid material during forming, which affects parts properties and therefore their quality.Extrusion tests show how thermal exchanges influence quality of thixoforged parts made of 7075 aluminium alloys at high solid fraction by modifying process parameters like forming speed, tool temperature and tool thermal protector.Thus an optimum in terms of thermal exchanges has to be found between surface quality and mechanical properties of the part.A direct application is the evaluation of surface quality of thixoforged thin wall parts made of 7075 aluminium alloy.

Detection of the Pandemic H1N1/2009 Influenza A Virus by a Highly Sensitive Quantitative Real-time Reverse-transcription Polymerase Chain Reaction Assay

A quantitative real time reverse-transcription polymerase chain reaction （qRT-PCR） assay with specific primers recommended by the World Health Organization （WHO） has been widely used successfully for detection and monitoring of the pandemic H1N1/2009 influenza A virus. In this study, we report the design and characterization of a novel set of primers to be used in a qRT-PCR assay for detecting the pandemic H1N1/2009 virus. The newly designed primers target three regions that are highly conserved among the hemagglutinin （HA） genes of the pandemic HlN1/2009 viruses and are different from those targeted by the WHO-recommended primers. The qRT-PCR assays with the newly designed primers are highly specific, and as specific as the WHO-recommended primers for detecting pandemic H1N1/2009 viruses and other influenza viruses including influenza B viruses and influenza A viruses of human, swine, and raccoon dog origin. Furthermore, the qRT-PCR assays with the newly designed primers appeared to be at least 10-fold more sensitive than those with the WHO-recommended primers as the detection limits of the assays with our primers and the WHO-recommended primers were 2.5 and 25 copies of target RNA per reaction, respectively. When tested with 83 clinical samples, 32 were detected to be positive using the qRT-PCR assays with our designed primers, while only 25 were positive by the assays with the WHO-recommended primers. These results suggest that the qRT-PCR system with the newly designed primers represent a highly sensitive assay for diagnosis of the pandemic HIN1/2009 virus infection.

A new process monitoring method based on noisy time structure independent component analysis

Conventional process monitoring method based on fast independent component analysis(Fast ICA) cannot take the ubiquitous measurement noises into account and may exhibit degraded monitoring performance under the adverse effects of the measurement noises. In this paper, a new process monitoring approach based on noisy time structure ICA(Noisy TSICA) is proposed to solve such problem. A Noisy TSICA algorithm which can consider the measurement noises explicitly is firstly developed to estimate the mixing matrix and extract the independent components(ICs). Subsequently, a monitoring statistic is built to detect process faults on the basis of the recursive kurtosis estimations of the dominant ICs. Lastly, a contribution plot for the monitoring statistic is constructed to identify the fault variables based on the sensitivity analysis. Simulation studies on the continuous stirred tank reactor system demonstrate that the proposed Noisy TSICA-based monitoring method outperforms the conventional Fast ICA-based monitoring method.

Rheological characterization of A201 aluminum alloy

The thermodynamic characterization as well as the rheological characterization of the A201 alloy were conducted.Thermodynamic simulations (CALPHAD method) and calorimetric experiments were performed to determine the solidus and liquidus temperatures, the melting range and the sensitivity of the solid fraction at the thixoforming temperatures.The rheology of aluminium alloy A201 was examined using a high temperature Searle rheometer.The flow behaviour was analyzed with concentric cylinders of graphite to avoid chemical interactions with the liquid or semi-solid aluminium.The rotational body was grooved to prevent a phenomenon called wall slippage.Continuous cooling experiment was used to observe the shear rate effects on the flow behaviour.It can be seen that the viscosity level decreases at higher shear rates.Shear rate jump experiment was carried out to evaluate the steady state flow curve within the analyzed shear rate range from 60 s-1 to 260 s-1.It is found that the power law indexes are-1.35 and-1.49 for 35% and 45% solid fraction, respectively.Finally, some mechanical property data of as-cast and as-thixoformed A201 alloy are included indicating the potential for high strength applications.

Simultaneous Effects of Hydrostatic Pressure and Conduction Band Non-parabolicity on Binding Energies and Diamagnetic Susceptibility of a Hydrogenic Impurity in Spherical Quantum Dots

Simultaneous effects of conduction band non-parabolicity and hydrostatic pressure on the binding energies of 1S, 2S, and 2P states along with diamagnetic susceptibility of an on-center hydrogenic impurity confined in typical GaAs/Alx- Ga1-x As spherical quantum dots are theoretically investigated using the matrix diagonalization method. In this regard, the effect of band non-parabolieity has been performed using the Luttinger-Kohn effective mass equation. The binding energies and the diamagnetic susceptibility of the hydrogenic impurity are computed as a function of the dot radius and different values of the pressure in the presence of conduction band non-parabolicity effect. The results we arrived at are as follows： the incorporation of the band edge non-parabolicity increases the binding energies and decreases the absolute value of the diamagnetic susceptibility for a given pressure and radius; the binding energies increase and the magnitude of the diamagnetic susceptibility reduces with increasing pressure.

Design and optimization of vector coil sensor suited to magnetometric resistivity method

Magnetometric resistivity(MMR)method is a new way to detect dam leakage.The coil sensor is generally used to collect data in geophysical exploration methods.Given the characteristics of accurate vector data requirements and high sensitivity requirement,a three-component MMR air-core coil sensor is designed.Through the analysis of sensor sensitivity and coil structure parameters,the coil structure and turn number are designed.By analyzing the noise source of the sensor,a suitable amplifier is selected to reduce the background noise of the system.Through the analysis of the three-component non-orthogonal angles,the parameters of the non-orthogonal angles of the coils are corrected.Finally,a three-component MMR induction magnetic field sensor is designed.The volume of the sensor is controlled at 0.027 m 3.The background noise of X、Y and Z are 5.030435 nV/Hz@380 Hz and magnetic field sensitivities are 0.18995 pT/Hz@380 Hz.The three channels have good consistency,and the three-component nonorthogonal angles correction error of three components is controlled within 0.2%.