多发性硬化与脑小血管病的脑白质高信号特征的差异比较

目的探讨无高血压的年轻多发性硬化患者与症状性脑小血管病患者脑白质高信号特征的差异。方法检查了77例多发性硬化患者和88例症状性脑小血管病患者,采用分区病变描述、半定量视觉评分量表和自动像素定量方法对T2图像进行比较。结果多发性硬化白质高信号区病变体积小、数量少,多见于脑室周围和皮质旁白质,尤其见于枕部和颞部。而脑小血管病的白质高信号区病变体积较大,数量较多,多见于皮质下白质,尤其是额叶和基底节区。结论本研究揭示的影像学特征提高了多发性硬化和脑小血管病的鉴别,提示了两种疾病的不同病理性质。

噬菌体在鲑鳟鱼细菌病治疗中的应用研究进展

噬菌体是一种营细菌生存的病毒,具有感染和裂解细菌的特性,且杀菌的高度特异性与细菌耐药无关,是可取代抗生素控制鲑鳟鱼细菌性疾病的新宠。本文通过介绍噬菌体的生物学特性,综述鲑鳟鱼致病菌相关的噬菌体研究新进展,结合鲑鳟鱼致病菌的特性探讨了噬菌体研究的问题及应对措施,以期为噬菌体在鲑鳟鱼细菌病防治中的应用提供参考。

水流作用下圆柱局部冲刷三维数值模拟

孤立式桥墩周围的局部冲刷一直是导致桥墩失稳的重要因素。国内外针对圆形墩柱周围的水流绕流流态及局部冲刷情况做了许多研究,但对大尺度墩柱的研究仍不完善。利用FLOW-3D三维模拟软件中大涡模拟紊流模型模块以及泥沙冲刷模块,对不同尺度的圆柱周边的局部冲刷进行系统模拟研究。计算结果表明,在不同圆柱直径下,圆柱的迎水侧、背水侧以及对称侧的平衡冲刷深度始终保持着特定的比例关系。同时,圆柱周围的最大冲刷深度随圆柱直径的增大而增大,但其与圆柱直径的比值随圆柱直径增大而减小,并呈现出收敛的趋势。期望数值模拟研究结果,能够较好地为预测实际工程中大尺度圆柱周围的冲刷坑深度及形态提供参考依据。

面向再生编码云存储的高效隐私保护审计方案

再生码技术在大数据分布式云存储中具有重要的应用价值,如何利用编码技术构造轻量型的隐私保护和审计机制仍然是基于再生码的分布式云存储系统尚未解决的问题.采用质询响应计算安全外包的策略和动态随机线性掩码技术,提出了一种适用于再生码云存储系统隐私保护数据审计方案,方案不仅能实时完成服务器质询响应数据的在线动态加密,而且在云存储节点和审计者之间构造了一种隐私计算协同外包的审计策略.理论分析和实验表明,该方案实现了完备的隐私保护机制和审计安全性,与现有工作相比,具有较快的实现效率.

浅滩影响下的近岸低频波浪研究

周期在25～300 s之间的低频波浪对海岸附近的泥沙输运、港内水面波动和泊稳等都有重要影响。虽然针对低频波浪的理论研究已有较多成果,但是结合实际工程针对浅滩上低频波浪的研究较少。采用非静压波浪模型SWASH对浅滩上波浪进行数值模拟,并对时域水面结果进行长短波分离,探讨低频波浪在浅滩上的演变规律。模拟结果显示,浅滩上低频波浪主要由约束长波和自由长波组成,约束长波占主要部分;低频波浪的能量来自于短波波群能量的转化;低频波浪能量增长率与h^(-5/2)成正比;不同水文条件下浅滩对低频波浪演变和近岸低频波浪运动的影响具有一定规律性。

基于三维浅水方程的刚性植被水流特性研究

河道中植被的存在会影响河道的过流和挟沙能力。为了研究植被对水流的作用,在已开发的准三维浅水波运动模型控制方程中加入了杆状植被阻力项,并在绕流拖曳力系数计算中考虑了刚性植被的遮蔽效应,同时引入前人提出的植被密度的概念。对改进后的模型利用前人的实验资料进行了验证。模型对植被范围以下和以上流速垂向分布模拟效果良好。利用水箱测定了植被影响下的水流流速,结果表明植被密度是影响阻力的主要因素,而植被的排列方式影响不大;数学模型模拟植被范围和以上的水流速度及紊动能量垂向分布结果与实测值符合较好。

关节镜下治疗跖趾关节痛风性关节炎的临床疗效

目的探讨关节镜下手术治疗第一跖趾关节急慢性痛风性关节炎的方法和疗效。方法对20例急慢性痛风性关节炎患者进行关节镜检查,利用刮匙除去紧密附着在关节软骨上的尿酸盐结晶,利用刨刀刨削充血、增生的滑膜及其附着的尿酸盐结晶;用碳酸氢钠注射液冲洗关节腔。术后抗炎镇痛,继续饮食控制及降尿酸等治疗。结果 20例患者术后病情均得到不同程度的缓解。经3～24个月的随访观察,其中3例复发,复发时间最短为术后6个月,最长为术后1年,发作部位均在对侧或其他关节。有3例术侧有微痛、红。复发原因是患者未控制饮食,也未服用抗痛风药物。结论关节镜下手术治疗急慢性痛风性关节炎是一种见效快、创伤小、效果稳定的方法,值得临床推广应用。但它仅是一种局部治疗方法,可以防止晚期骨性关节炎的早期发生,但不能代替排酸、抑酸及饮食控制的治疗。

挟沙水流幂律湍流模式研究

围绕如何描述挟沙水流湍流特性和确定湍流模式这一工程设计所关心的问题,建立了一种合理实用的挟沙水流湍流特性表达式。通过湍流理论分析和挟沙水流湍流特性试验,构建了与浑水含沙浓度相关的一种非牛顿切应力型湍流模式——幂律湍流模式,进而求解雷诺方程得到挟沙水流的流速分布,回归分析挟沙水流湍流特性试验数据,率定流速分布表达式参数,从而确定挟沙水流幂律湍流模式参数。

miR-146a和miR-221在儿童急性T淋巴细胞白血病中的表达及其临床意义

目的:探讨急性T淋巴细胞白血病(T-ALL)患儿外周血单个核细胞(PBMNC)中miR-146a和miR-221表达水平及临床意义。方法:选取海南省第三人民医院收治的初诊T-ALL患儿130例(T-ALL组)和体检健康者50例(对照组)。T-ALL患儿以治疗前作为初发组,诱导治疗d 33达完全缓解者作为缓解组(n=98),未完全缓解者作为难治组(n=32)。采用实时荧光定量PCR方法检测各组PBMNC的miR-146a及miR-221表达水平。ROC曲线分析miR-146a及miR-221对T-ALL的诊断价值,Pearson相关分析评价T-ALL患儿miR-146a及miR-221表达与白细胞计数的相关性。结果:T-ALL组PBMNC的miR-146a及miR-221表达水平均明显高于对照组(5.83±1.54 vs 0.96±0.17)(7.13±2.60 vs 1.64±0.51)(P<0.01)。难治组PBMNC的miR-146a及miR-221表达水平均明显高于缓解组和初发组(8.74±2.35 vs 1.70±0.63,5.83±1.54)(11.316±4.83 vs 2.62±0.85,7.13±2.60)(P<0.01)。miR-146a及miR-221表达水平与白细胞计数、危险度分型和MRD相关(P<0.05)。ROC曲线分析显示,miR-146a及miR-221诊断T-ALL的最佳截值分别为3.90和5.28,2项联合诊断T-ALL的AUC(95%CI)为0.835(0.764-0.892),其敏感度和特异度分别为85.0%和77.2%。相关分析显示,T-ALL患儿PBMNC的miR-146a及miR-221表达水平与白细胞计数均呈正相关(r=0.705,r=0.653,P<0.01),miR-146a与miR-221呈正相关(r=0.784,P<0.01)。结论:miR-146a及miR-221在T-ALL患儿中表达上调,且与T-ALL患儿预后密切相关,2项联合检测对T-ALL诊断具有一定价值。

The Effects of Compound Chinese Medicine Immune Additives on Growth Performance and Antioxidant Capacity of Acipenser schrenckii

[ Objective] The aim was to explore the effects of compound Chinese medicine on growth and antioxidant capacity of Acipenser schrenckii, and to provide a foundation for the application of traditional Chinese medicine as immune additives in sturgeon aquaculture production. [Methods] Three kinds of compound Chinese medicines （respectively called A, B and C） were added into basic material feed as feed additives, continuous fed 1 ^＋ age Acipenser schrenckii for 35 d, then weight gain rate was determined and superoxide dismutase （SOD） activity, malondialdehyde （MDA） content, total antioxidant capacity （T-AOC） and glutathione peroxidase （GSH-PX） activity in serum and liver were detected. [ Results ] Chinese medicine formulae could increase the superoxide dismutase （SOD） activity, total antioxidant capacity （ToAOC） and glutathione per- oxidase （GSH-PX） in serum and liver of sturgeon. Especially SOD enzyme activity of serum in the three formulae groups was significantly higher （ P 〈 0.05） than control group, SOD enzyme activities of fish liver in group A and C were significantly higher （ P 〈 0.05） than control group; T-AOC activities of serum and liver in the three formulae groups were both incressed, but had no significant differences with that of the control group; only GSH-PX activities of fish serum in group B and C had significant differences （P〈0.05） with that of control group, GSH-PX activities of liver in the three formulae groups had no significant differences with that of control group; and traditional Chinese medicine could significantly reduce malondialdehyde （MDA） content of sturgeon serum, MDA contents of serum and liver in three formulae groups had significant differences （P 〈 0.05） with that of control group. [ Conclusion] The selected three kinds of compound Chinese medicine additives had different degree of ability to improve sturgeon antioxidant function.

Study on Hydrodynamic Characteristics of Wave Turbulent Bottom Boundary Layer Using A Large-Sized Wave Flume

Experimental studies were conducted in a super-large wave flume,aiming at uncovering the hydrodynamic characteristics involved in the turbulent wave boundary layer of full scale environment.An explicit formula of boundary layer thickness on rough turbulent flow was presented based on the measured velocity data of the present study and collected experimental data on wave boundary layer.It was found that the bottom wave-associated nominal stresses under the conditions of prototype scale tests suppress the vertical turbulence scattering upward over the boundary layer,which accounts for thickening of the boundary layer under wave condition.Such effect has yet not been reported in the literatures using oscillatory U-tube or small-sized wave flume.The phase inconsistency in the turbulent boundary layer to the free stream velocity(velocity immediately outside the boundary layer)is within15°,which is remarkably smaller than the results from oscillatory U-tubes,as well as the larger wave flume experiment presented by Xie et al.(2021),showing that the coarser bed would further reduce the phase lead.The intensity of the vertical turbulent component is approximately 1/2 of the horizontal component,which has larger ratio compared with the value of 1/5 reported by previous studies.Especially,it was also found that the vertical turbulent energy was approximately 3/4 of the turbulent energy in spanwise directions(y-direction).This means that the turbulent fluctuation has similar order in all three-directions(x,y,z)in a full scale environment and highlights that the turbulent components in all the three directions should not be neglected when calculating the total turbulent energy.

Finite Spectral Semi-Lagrangian Method for Incompressible Flows

A new semi-Lagrangian (SL) scheme is proposed by using finite spectral regional interpolation and adequate numerical dissipation to control the nonlinear instability.The finite spectral basis function is C1 continuous at the boundary and is easy to construct.Comparison between numerical and experimental results indicates that the present method works well in solving incompressible Navier-Stokes equations for unsteady flows around airfoil with different angles of attack.

Molecular Typing of Aeromonas hydrophila Isolated from Common Carp in Northeast China

A total of 59 isolates of Aeromonas hydrophila were collected from common carp suffering from freshwater fish hemorrhage disease in 13 fishing grounds in the northeast China, and their phenotypic and genetic characteristics were investigated. All of the isolates were identified as A. hydrophila by traditional biochemical method and yielded a 686-bp DNA fragment of the 16S rDNA gene in the PCR experiments. Collected strains were also evaluated for their susceptibility to 17 different antibiotics. The isolates showed an even trend of the resistance and sensitivity to drugs, highly sensitive to antibiotics, such as Levofloxacin, PolymyxinB, Ofloxacin and resistant to antibiotics, such as Bristopen, Lincomycin, Ampicillin, Teicoplanin. Evaluation of genetic diversity was performed on all isolates by molecular typing with enterobacterial repetitive intergenic consensus （ERIC-PCR） method. The results showed that three different types, i.e. type I, ]I, and type ~I, were found in 59 isolates and type III accounted for a large proportion of 54.84%. There was no dominant difference between the tendency of the isolates of Heilongjiang Province and Jilin Province in these three types, which showed DI 〉 I 〉 I, while the isolates of Liaoning Province showed III 〉 II 〉 I. The percentage of different types in different provinces varied in each other; however, they didn＇t show any obvious regional or cluster-specific branches. In conclusion, the ability to distinguish Aeromonas hydrophila strains from diseased common carp with ERIC-PCR would be useful for epidemiological investigation and population genetic analysis of this pathogen in China.

Preoperative 3T high field blood oxygen level dependent functional magnetic resonance imaging for glioma involving sensory cortical areas

Background Localization of sensory cortical areas during the operation is essential to preserve the sensory function. Intraoperative direct electrostimulation under awake anesthesia is the golden standard but time-consuming. We applied 3T high field blood oxygen level-dependent （BOLD） functional magnetic resonance imaging （fMRI） to identify the relationship between glioma and cortical sensory areas preoperatively and to guide intraoperative direct electrostimulation for quick and precise localization. Methods Five glioma patients with sensory cortex involvement by or next to the lesion had preoperative BOLD fMRI to determine the spatial relationship of cortical sensory areas to the tumours. Bilateral hand opposite movement was performed by these patients for fMRI. Precentral and postcentral gyri were identified by electrical stimulation during the operation. Karnofsky Performance Status scores of the patients＇ pre- and postoperative and the role of BOLD fMRI were evaluated. Results The cortical sensory areas were all activated in five glioma patients involving postcentral gyrus areas by BOLD fMRI with bilateral hand opposite movement. The detected activation areas corresponded with the results from cortical electrical stimulation. Conclusions The relationship between cortical sensory areas and tumour can be accurately shown by BOLD fMRI before operation. And the information used to make the tumour resection could obtain good clinical results.

Relationship between magnetic resonance imaging and molecular pathology in patients with glioblastoma multiforme

Background Glioblastoma multiforme （GBM） is the most common and lethal primary brain tumor in adults. Magnetic resonance imaging （MRI） is routinely used in the diagnosis, characterization and clinical management of GBM. The diagnosis and treatment of GBM is largely guided by histopathology and immunohistochemistry. This study aimed to identify the relationship between magnetic resonance features and molecular pathology of GBM. Methods MRI images of 43 glioblastoma patients were collected. Four imaging features, degree of edema, contrast tumor enhanced/T2 ratio, multiple lesions and tumor across the midline, were selected to identify their relationship with P53, Ki-67 and O6-methylguanine-DNA methltransferase （MGMT） expression in patients with GBM. The relationship between imaging features and molecular pathology was studied by chi-square test using the software SPSS 13.0. Results High expression of P53 was found correlated with low contrast tumor enhancedFF2 ratio, low expression of Ki-67 was correlated with multiple lesions and high expression of KI-67 may be related with tumor across the midline, low expression of MGMT was correlated with edema. Conclusion Some MRI features such as the degree of edema, contrast tumor enhanced/T2 ratio, multiple lesions and tumor acrossing the midline are correlated with P53, Ki-67 and MGMT of GBM.

Proton magnetic resonance spectroscopy predicts radiotherapy response and time-to-progression in high-grade gliomas after surgery

Background Reliable early prediction response to therapy and time-to-progression （TTP） remain an important goal of high-grade gliomas （HGGs） research. Proton magnetic resonance spectroscopy （1H-MRS） has been applied with variable success in clinical application, and we hypothesize that 1H-MRS in predictive value should perform well as a marker of TTP in patients treated with radiotherapy （RT） after surgery. Methods 1H-MRS was performed before surgery on 25 patients who had undergone resection of HGGs; then the ratios of lipid/creatine （Lip/Cr） and myo-inositol/creatine （ml/Cr） were determined in the solid tumor. RT response was classified as follows： complete resolution （CR）, partial response （PR）, stable disease （SD）, and progressive disease （PD） by comparison of pre-treatment and post-radiotherapy scans. TTP was defined at the time to radiographic progression by MacDonald criteria. Correlation was evaluated between the ratios of Lip/Cr, ml/Cr and treatment response, TTP. The chi-square test and Pearson correlation test were used for data analyses. Results Multivariate analysis revealed that the prognostic value of spectroscopic variables was independent of age, sex, WHO histologic grade, extent of surgery, and Karnofsky score （KPS）. The correlation between the ratios of lipid/Cr and TTP was significant （r=0.894, P=0.000）, and between the ratios of ml/Cr and TTP was also significant （r=0.891, P=-0.000）. As predicted, RT response correlated significantly with TTP （r=0.59, P=0.002）： median TTP was 49.9 days for patients with PD compared with 202.7 days for SD, 208.0 days for PR, and 234.5 days for CR. Conclusion The ratios of Lip/Cr and ml/Cr of the solid tumor region before surgery could provide important information in predicting RT response and TTP in patients with HGGs treated by radiation alone after surgery.

Dynamic radiological change of gliomas located in the paralimbic system and its clinical significance

Background The paralimbic system, which is composed of three parts, is an important functional unit. Gliomas located in the region remain a challenge for clinical treatment. However, the dynamic change of gliomas in the area has not been well documented. The purpose of this study was to identify the growth tendency of gliomas located in the paralimbic system and to obtain some suggestions for clinical treatment. Methods Eleven cases of gliomas located in the paralimbic system were recruited in the study. All of them were proven by pathology. Analysis of the serial radiological examinations in each patient was performed from the initial to the final examination, taking into consideration the following items： initial tumor location, final location and the growth tendency. Results In the initial and final examinations the ratios of insula involvement were 64% and 100%, respectively. On the other hand, the ratios of gliomas located in two or more parts of paralimbic system increased from 64% to 100% during the dynamic examination. Conclusions Even though the paralimbic system is composed of three independent anatomical parts, gliomas tend to involve all three parts, especially the insula. Therapeutic plans should aim at the whole region of the system, even during the early stages of gliomas.

Regional homogeneity analysis on acupoint specificity with resting-state functional magnetic resonance imaging

Background The mechanism of acupuncture analgesia in craniotomy has been widely studied. However, the theoretical basis for selection of acupoints has not been examined. In this study, we used the regional homogeneity method blood oxygen level-dependent （BOLD） signals to determine changes in brain activity in response to transcutaneous electrical stimulation on acupoints and non-acupoints in resting state functional magnetic resonance imaging （fMRI）.Methods Twelve healthy volunteers were enrolled in this study. BOLD fMRI scanning of the brain was performed for 306 seconds before and 30 minutes after transcutaneous electrical stimulation on acupoints UB63 （Jinmen）, LV3 （Tai chong）, ST36 （Zusanli）, and GB40 （Qiuxu）. The procedure was repeated after one week with stimulation on non-acupoints （one was 9 above BL67, the second was 12 above BL67 （Kunlun）, the third was 7 above KI3, and the fourth was 10 above KI3 （Taixi））.Results The regional homogeneity in the acupoint group was increased in the left thalamus, caudate, putamen, lentiform nucleus （BA19, 30, 39）, postcentral gyrus, precentral gyrus （BA3, 4, 30, 32）, calcarine fissure, middle temporal gyrus （BA30）, right superior temporal gyrus, inferior temporal gyrus （BA38）, cuneus, and precuneus （BA7, 19） when compared to the non-acupoint group. The regional homogeneity of the acupoint group was decreased in the left cerebellum posterior lobe, middle frontal gyrus （BA10）, double-side precuneus （BA7）, and the postcentral gyrus （BA40）.Conclusions The brain region activated following acupoint stimulation is the ipsilateral pain-related brain region, which may relate to the therapeutic effect of acupuncture on pain relief. Further acupoint stimulation causes different central nervous responses compared to non-acupoint stimulation.