Optimal time for subarachnoid transplantation of neural progenitor cells in the treatment of contusive spinal cord injury

This study aimed to identify the optimal neural progenitor cell transplantation time for spinal cord injury in rats via the subarachnoid space. Cultured neural progenitor cells from 14-day embryonic rats, constitutively expressing enhanced green fluorescence protein, or media alone, were injected into the subarachnoid space of adult rats at 1 hour （acute stage）, 7 days （subacute stage） and 28 days （chronic stage） after contusive spinal cord injury. Results showed that grafted neural progenitor cells migrated and aggregated around the blood vessels of the injured region, and infiltrated the spinal cord parenchyma along the tissue spaces in the acute stage transplantation group. However, this was not observed in subacute and chronic stage transplantation groups. 04- and glial fibrillary acidic protein-positive cells, representing oligodendrocytes and astrocytes respectively, were detected in the core of the grafted cluster attached to the cauda equina pia surface in the chronic stage transplantation group 8 weeks after transplantation. Both acute and subacute stage transplantation groups were negative for 04 and glial fibrillary acidic protein cells. Basso, Beattie and Bresnahan scale score comparisons indicated that rat hind limb locomotor activity showed better recovery after acute stage transplantation than after subacute and chronic transplantation. Our experimental findings suggest that the subarachnoid route could be useful for transplantation of neural progenitor cells at the acute stage of spinal cord injury. Although grafted cells survived only for a short time and did not differentiate into astrocytes or neurons, they were able to reach the parenchyma of the injured spinal cord and improve neurological function in rats. Transplantation efficacy was enhanced at the acute stage in comparison with subacute and chronic stages.

Available parking space occupancy change characteristics and short-term forecasting model

Based on an available parking space occupancy （APSO） survey conducted in Nanjing, China, an APSO forecasting model is proposed. The APSO survey results indicate that the time series of APSO with different time-sections are periodical and self-similar, and the fluctuation of the APSO increases with the decrease in time-sections. Taking the short-time change behavior into account, an APSO forecasting model combined wavelet analysis and a weighted Markov chain is presented. In this model, an original APSO time series is first decomposed by wavelet analysis, and the results include low frequency signals representing the basic trends of APSO and several high frequency signals representing disturbances of the APSO. Then different Markov models are used to forecast the changes of low and high frequency signals, respectively. Finally, integrating the predicted results induces the final forecasted APSO. A case study verifies the applicability of the proposed model. The comparisons between measured and forecasted results show that the model is a competent model and its accuracy relies on real-time update of the APSO database.

Strategies for multi-step-ahead available parking spaces forecasting based on wavelet transform

A new methodology for multi-step-ahead forecasting was proposed herein which combined the wavelet transform(WT), artificial neural network(ANN) and forecasting strategies based on the changing characteristics of available parking spaces(APS). First, several APS time series were decomposed and reconstituted by the wavelet transform. Then, using an artificial neural network, the following five strategies for multi-step-ahead time series forecasting were used to forecast the reconstructed time series: recursive strategy, direct strategy, multi-input multi-output(MIMO) strategy, DIRMO strategy(a combination of the direct and MIMO strategies), and newly proposed recursive multi-input multi-output(RECMO) strategy which is a combination of the recursive and MIMO strategies. Finally, integrating the predicted results with the reconstructed time series produced the final forecasted available parking spaces. Three findings appear to be consistently supported by the experimental results. First, applying the wavelet transform to multi-step ahead available parking spaces forecasting can effectively improve the forecasting accuracy. Second, the forecasting resulted from the DIRMO and RECMO strategies is more accurate than that of the other strategies. Finally, the RECMO strategy requires less model training time than the DIRMO strategy and consumes the least amount of training time among five forecasting strategies.

Forecasting available parking space with largest Lyapunov exponents method

The techniques to forecast available parking space(APS) are indispensable components for parking guidance systems(PGS). According to the data collected in Newcastle upon Tyne, England, the changing characteristics of APS were studied. Thereafter, aiming to build up a multi-step APS forecasting model that provides richer information than a conventional one-step model, the largest Lyapunov exponents(largest LEs) method was introduced into PGS. By experimental tests conducted using the same dataset, its prediction performance was compared with traditional wavelet neural network(WNN) method in both one-step and multi-step processes. Based on the results, a new multi-step forecasting model called WNN-LE method was proposed, where WNN, which enjoys a more accurate performance along with a better learning ability in short-term forecasting, was applied in the early forecast steps while the Lyapunov exponent prediction method in the latter steps precisely reflect the chaotic feature in latter forecast period. The MSE of APS forecasting for one hour time period can be reduced from 83.1 to 27.1(in a parking building with 492 berths) by using largest LEs method instead of WNN and further reduced to 19.0 by conducted the new method.

Lymphoepithelioma-Like Carcinoma of Parapharyngeal Space—A Case Report with Review of Literature

Extra-nasopharyngeal lymphoepithelioma-like carcinomas (LELC) are uncommon epithelial tumors. A few isolated case reports and series are available in literature involving the larynx, pharynx, salivary gland, lung etc., but involvement in the parapharyngeal space has not yet been reported. We aim to highlight one such case that has a clinical and radiological characteristic of a benign lesion whilst the histopathology reveals an infiltrating neoplasm. The typical clinical aggressiveness of a classical LELC of extra-nasopharyngeal lesion as described in literature is not present in our case. Also seen is an uncommon finding of abnormal branching of left external carotid artery. There is no standard treatment protocol for such a tumor;however, wide excision of this tumor in the parapharyngeal space via trans-cervical, trans-mandibular, trans-palatal approach has shown good and satisfactory tumor control of the primary site so far.

Bone marrow mesenchymal stem cell transplantation for treatment of spinal cord injury An in vivo magnetic resonance imaging tracking study

Non-invasive tracing in vivo can be used to observe the migration and distnbution of grafted stem cells, and can provide experimental evidence for treatment. This study utilized adenovirus-carrying enhanced green fluorescent protein （AD5/F35-eGFP） and superparamagnetic iron oxide （SPIO）-Iabeled bone marrow mesenchymal stem cells （BMSCs）. BMSCs, double-labeled by AD5/F35-eGFP and SPIO, were transplanted into rats with spinal cord injury via the subarachnoid space. MRI tracing results demonstrated that BMSCs migrated to the injured spinal cord over time （T2 hypointensity signals）. This result was verified by immunofluorescence. These results indicate that MRI can be utilized to trace in vivo the SPIO-labeled BMSCs after grafting.

Developing biophilic intermediate spaces for Arctic housing:Optimizing the thermal,visual,and energy performance

Connecting occupants to the outdoor environment and incorporating biophilic design principles are challenging in extreme Arctic climatic conditions.Existing Arctic housing models do not provide efficient thermal and daylight transitions which are essential for the well-being and cultural needs of their occupants.To address these challenges,this research develops free-running biophilic intermediate spaces,integrated into an existing Arctic housing model.Numerical simulation methods are employed to optimize the primary and secondary architectural design variables for 26 case studies of intermediate spaces.Primary variables include volume,transparency ratio,and orientation.Secondary variables include materials and physical adjacency.Temperature,Daylight Factor/Autonomy,and Energy Use are evaluated as performance indicators.Results reveal that free-running intermediate spaces with 6 meters depth and a transparency ratio above 50%provide efficient indoor–outdoor transitions regarding thermal,visual,and energy performance.Such architectural configurations contribute to an approximately 5%reduction in energy consumption within the housing unit compared to the baseline.Opening side windows prevents the risk of overheating during the summer by reducing the average indoor temperature of intermediate spaces by 7°C but increases the overall energy consumption.As a potential alternative to double-glazing,polycarbonate sheets enable efficient thermal performance by increasing the average indoor temperature of intermediate spaces by approximately 15°C during the cold Arctic seasons.Using polycarbonate sheets results in a 16.6%reduction in energy consumption compared to using double-glazing material in intermediate space,and a 26%reduction from the baseline.Research outcomes contribute to efficient indoor–outdoor connections and energy efficiency in Arctic housing.

虚拟空间具身在场的知觉之维——基于可供性具身认知视角

针对当前数字技术对虚拟空间身体体验建构原理的理论缺失,以及虚拟空间具身性在场体验难以实现的困境,通过比较法分析传统空间表象认知中对经验身体的认识,以及梅洛庞蒂身体转向中对知觉的引入,探讨基于可供性具身认知将空间理解为具有生态信息的知觉空间,将虚拟空间定义为可供用户直接感知并采取行动的知觉空间。运用逻辑分析法用可供性具身认知的“空间-身体-知觉”的同一性特征,解释数字技术下虚拟空间的具身性知觉体验的原理,即通过模拟知觉、身体知觉代理以及身体知觉统合方法,将虚拟空间营造成契合用户知觉、行为规律的具身性知觉体验场所。

Galileo高精度定位服务的空间信号误差及精密单点定位评估

Galileo高精度定位服务(high accuracy service,HAS)利用E6B信号向全球用户播发免费精密卫星轨道、钟差和码偏差改正信息,在卫星高精度实时应用领域有重要意义.评估其空间信号误差及精密单点定位(precise point positioning,PPP)性能是用好HAS的重要前提.基于2023年12月1日至31日的HAS轨道钟差产品进行评估测试,Galileo卫星轨道产品在径向(R)、切向(A)和法向(C)的均方根误差(root mean square error,RMSE)分别为3.24 cm、7.40 cm和6.85 cm,GPS分别为4.52 cm、8.19 cm和6.71 cm;Galileo钟差产品的标准差(standard deviation,STD)为0.16 ns,GPS为0.26 ns.基于欧洲10个测站PPP的实验结果表明:Galileo在E、N、U方向的定位精度分别为6.44 cm、4.65 cm和11.36 cm,GPS分别为7.42 cm、5.78 cm和12.04 cm,联合定位分别为4.11 cm、3.10 cm和7.56 cm,HAS可以满足高精度定位需求.

雄安新区起步区地下空间资源开发利用地质适宜性及资源量评价

【研究目的】雄安新区作为千年大计、国家大事,开发利用地下空间资源可有效缓解“环境污染、资源短缺、交通拥堵”等“大城市病”问题,促进新区高质量发展。【研究方法】本文以雄安新区起步区为研究对象,通过层次分析法,分析了影响研究区地下空间资源开发利用的地质因素,建立了地下空间资源开发利用地质环境适宜性评价指标体系,评价了地下空间开发利用地质适宜性,并估算了地下空间可利用资源量。【研究结果】研究结果表明,研究区地下空间开发利用地质适宜性评价指标可划分为4大类10个指标,主要影响指标为含水砂层、地面沉降、液化砂土、水土腐蚀性等;按浅层、次深层和深层将评价结果划分为适宜区、一般区和敏感区,适宜区和一般区总面积约占起步区面积80%以上,资源量整体较好。【结论】该评价结果为起步区地下空间资源开发利用提供了参考,为起步区高质量建设及可持续发展提供了可靠的技术支撑;同时,地下空间资源开发利用具有不可逆性,易受地质环境因素影响,其开发利用必须因地制宜、合理规划、科学布局。

基于可供性理论下体育公园的环境分析与改造设计

体育公园作为城市生活中独特的体育绿色空间,能够满足群众进行日常的体育活动。但目前我国体育空间规划建设还处于初步阶段,建设上也存在着随意性和盲目性,主题性不够突出,功能区域布局、景观设计、基础设施建设、智慧化程度还不够完善。本研究从体育公园角度出发,将位于武汉市汉阳区的张之洞体育公园为案例研究,以可供性为理论支撑,借鉴苏剑鸣学者的可供性层次划分,探究使用者与体育公园可供性的深层关系,构建体育公园的可供性表现,对体育公园进行空间分析,提出体育公园空间的环境设计优化策略。

媒介可供性视角下抖音对地方形象的传播作用——以淄博为例

抖音短视频作为一种结合视听、定位和大数据技术的新兴融合媒介,兼具生产可供性、社交可供性和移动可供性,在构建地方认知、传播地方形象方面发挥着重要作用。抖音短视频的生产可供性赋予人和地方更大的内容生产自主性,让地方景观得以更加直观地被审阅和传播。移动可供性构建起虚实互嵌的新型地方空间样态,更能激发用户对地方形象的感知、想象和认可。抖音短视频已成为人们日常生活中重要的社交平台,其社交可供性使得地方情感在云上空间的高度情绪化媒介场域中不断发酵,让地方形象更加具有感染力和亲和力。

川中丘陵区典型小流域土壤氮素空间变异特征及影响因素研究

根据94个样点表层土壤(0—20 cm)氮素的化验数据,在ArcGIS 9.0平台上运用地统计学方法研究了川中丘陵区清流河流域土壤全氮和速效氮的空间变异特征及其影响因素。结果表明,研究区土壤全氮和速效氮含量总体水平较低,二者平均值分别为(0.85±0.03)g/kg和(63.8±25.4)mg/kg。土壤全氮含量总体上呈条带状或斑块状分布,高值区(>1.12 g/kg)主要分布于东部大清河下游的石子镇、苏家、互助一带,并以此为中心向北和向西逐渐降低,向西南呈现出先逐渐降低至沱江流域后又有所上升的趋势,低值区(<0.88 g/kg)主要分布于北部的大冶乡、凤天乡、双桥乡以及西部的安全、靖民、郭北一带;研究区土壤速效氮含量空间分布特征和全氮基本一致。研究区土壤全氮和速效氮含量与土壤母质、地形、土地利用方式、灌溉方式、土壤侵蚀、土壤pH和土壤质地等因素密切相关,其中在不同土壤母质、地形、土地利用方式、灌溉方式、土壤侵蚀状况和土壤质地下土壤全氮和速效氮含量差异达极显著或显著水平。

新疆膜下滴灌棉田土壤有效态氮空间分布特征

棉花膜下滴灌条件下的棉田土壤碱解氮、铵态氮含量变化是,0-10 cm土层与滴灌带垂直水平方向0-75 cm变化波动最大,其次是10-20 cm土层,20-60 cm变化比较小。硝态氮含量的水平变化有所不同,0-60 cm各层土壤变化均较大;棉花各生育时期土壤垂直向下0-60 cm土层碱解氮含量和盛花期铵态氮含量,由上向下呈比较均匀的直线递减变化,硝态氮含量是0-10 cm土层比10 cm以下高出1倍多,呈陡减变化趋势;膜下滴灌棉田土壤碱解氮含量随棉花生育进程逐渐下降,但在棉花生长发育的整个过程中始终保持在63-81 mg/kg较高水平,这是新疆获得大面积棉花高产的重要原因之一。

成都地区青少年下颌牙弓后段可利用间隙的预测研究

目的 探讨成都地区青少年牙弓后段可利用间隙的增龄性变化 ,为临床应用全牙弓间隙分析提供依据。方法 将 1999～ 2 0 0 0年在原华西医科大学口腔医院正畸科就诊的 11～ 2 0岁初诊患者 ,按纳入和排除标准筛选 ,共获得5 2 6例 ,其中男 2 32例 ,女 2 94例。按颌骨的矢状向、垂直向异常分类 ,通过头影测量分析获得牙弓后段可利用间隙量。分析成都地区青少年牙弓后段可利用间隙增龄性变化规律 ,用多变量相关分析检测牙弓后段间隙量与年龄、性别、安氏错类型、垂直骨面型的相关性。结果 (1)下颌牙弓后段间隙量与年龄、安氏错类型相关。 (2 )男女性的下颌牙弓后段可利用间隙增龄性变化曲线有一定差异。 (3)骨性Ⅲ类患者的牙弓后段可利用间隙增龄性变化量明显大于安氏Ⅰ、Ⅱ类患者。结论 成都地区青少年的数值同国外数值差异较大 ,提示在进行全牙弓间隙分析时 。

下牙弓后段可用间隙发育特征及其临床意义

目的 :研究下牙弓后段可用间隙生长变化特点。方法 :选取 188例下颌第一恒磨牙无近中移动及近中倾斜的初诊患者为研究对象 ,其中男性 76例 ,女性 112例。最小年龄 11岁 ,最大年龄 18岁。由同一技师按照同一头位拍摄X线全颌曲面断层片 ,在X线片上沿牙合平面测量下颌第一恒磨牙远中表面切线到升支前缘之间的距离 ,用SPSS/PC对测量值进行统计学处理。结果 :(1)可用间隙性别组差异有显著性 ,女性大于男性。 (2 )可用间隙生长量年龄组差异有显著性 ,14岁以上女性患者均值大于 14岁以下患者 ,差值为 1.12mm。 16岁以上男性患者均值大于 16岁以下患者 ,差值为 1.91mm。 (3 )可用间隙生长量在牙合发育阶段之间有高度显著性差异 ,在安氏错牙合类型之间差异无显著性。结论

基于三相桥臂坐标的SVPWM过调制方法

讨论了一种新型的SVPWM过调制方法,并对其过调制性能及谐波成分进行了分析。首先,对经典SVPWM技术进行了分析,探讨了常规过调制策略的实质。其次,引入了新的三相桥臂坐标,在该坐标下将现有的SVPWM的串行合成时间关系推导为并行。最后,给出了线性调制和过调制统一的求解模型,避免了现有过调制算法中控制角和保持角的计算。新方法取消了扇区的概念并简化了计算,可实现从线性调制到六阶梯模式的连续平滑调制。文中介绍了该过调制算法的基本原理,进行了仿真和实验。结果表明,该方法在线性调制和六阶梯模式下调制效果与经典SVPWM方法相当;而过调制区,其输出PWM波形的THD明显小于常规过调制方法。

小型啮齿动物种群系统调节复合因子理论的野外实验研究：食物可利用性和捕食对根田鼠种群空间行为的作用模式及其对种群调节的探讨

本项研究在野外围栏条件下，采用析因实验设计，测定食物可利用性和捕食对根田鼠（Ｍｉｃｒｏｔｕｓｏｅｃｏｎｏｍｕｓ）种群空间行为的作用模式。检验的特定假设为，高质量食物较大的可利用性能降低田鼠的攻击行为和活动；捕食能减少田鼠的活动。研究结果表明，食物可利用性能间接地和直接地影响根田鼠的空间行为。附加食物种群具有较高的密度和较小的巢区，且在诱捕期间具有较少的长距离活动和较低的攻击水平。捕食者的存在不直接影响攻击行为，但能影响诱捕期间的长距离活动，此为根田鼠对捕食者存在作出的直接反应。在阐明田鼠种群动态时，应仔细考虑上述因子相互作用的效应。

基于小波变换和粒子群小波神经网络组合模型的有效停车泊位短时预测

基于停车场有效停车泊位短时变化特性,提出了一种小波变换和粒子群小波神经网络组合预测方法。首先,通过选择合适的小波函数对有效停车泊位时间序列进行多尺度的小波分解与重构,然后对重构后的时间序列分别采用小波神经网络进行预测,并利用粒子群算法对神经网络初始参数的选取进行优化,最后将各自外推的预测结果进行合成,得到最终预测结果。实例分析表明：与单独使用小波神经网络模型相比,小波变换-粒子群小波神经网络模型的预测精度提高了5-7倍,且预测稳定性较好。

多次移植骨髓基质干细胞有利于脊髓损伤修复

[目的]研究多次经蛛网膜下腔移植骨髓基质干细胞对Wistar大鼠脊髓损伤的功能修复作用。[方法]骨髓基质干细胞经体外分离、培养并用Hoecst33342标记。按照Allen方法把60只在T10-T12平面损伤的Wistar大鼠随机分4组,A、B、C、D组(对照组)。在损伤平面蛛网膜下腔中段放置一硅胶管,在7d后,注入1×106个骨髓基质干细胞。在2、3、5、7、12周荧光显微镜、免疫组化检测骨髓基质干细胞在损伤段脊髓的存活、分布、分化情况并作计数观察。使用BBB评分观测后肢功能恢复。[结果]移植后7～14d骨髓基质干细胞达到高峰,在7d后表达巢蛋白及神经丝蛋白阳性。随时间的延长,移植在损伤部位的骨髓基质干细胞数量及神经元样细胞均有减少,但移植3次的细胞数减少速度较其他两组慢。移植3次组大鼠的BBB评分较移植1、2次组有明显的提高,P<0.01,有统计学意义。[结论]多次移植骨髓基质干细胞更有利于脊髓损伤的恢复。