Modeling and Control of Layer Height in Laser Wire Additive Manufacturing

Laser Wire Additive Manufacturing (LWAM) is a flexible and fast manufacturing method used to produce variants of high metal geometric complexity. In this work, a physics-based model of the bead geometry including process parameters and material properties was developed for the LWAM process of large-scale products. The developed model aimed to include critical process parameters, material properties and thermal history to describe the relationship between the layer height with different process inputs (i.e., the power, the standoff distance, the temperature, the wire-feed rate, and the travel speed). Then, a Model Predictive Controller (MPC) was designed to keep the layer height trajectory constant taking into consideration the constraints faced in the LWAM technology. Experimental validation results were performed to check the accuracy of the proposed model and the results revealed that the developed model matches the experimental data. Finally, the designed MPC controller was able to track a predefined layer height reference signal by controlling the temperature input of the system.     

细粒棘球绦虫烯醇酶(EgEnolase)基因的克隆和序列分析

目的 细粒棘球绦虫烯醇酶基因(EgEnolase)的克隆和所编码的蛋白质的结构、功能以及应用前景分析.方法 利用美国国家生物技术信息中心(NCBI,http://www.ncbi.nlm.nih.gov/)的在线分析工具BLASTx和瑞士生物信息学研究所的蛋白分析专家系统(ExPaSy.http://ca.expasy.org/),以及CBS Prediction Servers提供的蛋白序列在线分析工具,结合Vector NTI suite生物信息学分析软件,从GenBank中细粒棘球绦虫的表达序列标签(EST)数据库中发现烯醇酶的5'端和3'端的EST序列,根据预测的编码区两端序列设计引物,从细粒棘球绦虫青海绵羊分离株中用多聚酶链式反应(PCR)方法扩增其基凶组序列,PCR产物克隆到T载体,测序并分析序列中的内含子,以内含子两侧序列的合并序列为引物.采用不对称PCR方法去除其中的内含子序列,预测编码蛋白的结构和功能特征,并分析其应用前景.结果 细粒棘球绦虫青海绵羊株烯醇酶基因的基因组序列长为1 449 bp,含有两个长度分别为78 bp和69 bp的小内含子.该基因编码433个氨基酸;预测其氨基酸序列中含有一段跨膜区(aa104-124),N端在膜外,C端在膜内,恰好分为两个不同的功能域,膜内区是执行酶催化功能的主体,Swiss-Model模建的3D结构显示,膜内区由α螺旋和β折叠相间排列形成桶样结构,底物结合位点、催化中心、Mg2+结合位点等关键位点在空间上紧密靠近,位于桶形结构的中心.该蛋白还有一个潜在的核定位序列aa190-199 .该蛋白含有多个T、B细胞表位,且膜外的aa49-57.和膜内的aa228-236兼性的T、B细胞表位,线性B细胞表位aa206-213中包含了催化位点Glu210.结论 细粒棘球绦虫烯醇酶可能是一个位于虫体皮层表膜具有较好的免疫诊断和疫苗应用前景的膜蛋白,同时还可能进入细胞核调节基因表达.     

雷公藤内酯醇的细胞内定位研究?

目的：检测雷公藤内酯醇的细胞内定位,探讨其在细胞内的作用位点。方法采用4-溴甲基-7-甲氧基香豆素标记雷公藤内酯醇,与人肝癌细胞孵育;并与细胞核染料 PI 或细胞质膜染料 DiI 行双色荧光染色,用荧光显微镜观察。结果与对照相比,香豆素标记在紫外激发下呈特异性的淡蓝色荧光;与 DiI 共定位显示,香豆素标记在细胞质(膜)存在;与 PI 共定位显示,香豆素标记在细胞核存在,且荧光强于细胞质(膜)。结论雷公藤内酯醇在细胞内主要位于细胞核,其次是细胞质(膜),提示雷公藤内酯醇可能主要在细胞核内起作用,其次是在细胞质(膜)上起作用。     

2种骶裂孔穿刺方法的骶管麻醉效果比较

目的探索B 超定位引导骶裂孔穿刺法和传统体表定位法穿刺骶管麻醉的成功率与并发症。方法选取该院肛肠科和泌尿外科97 例会阴部手术患者,随机分为两组,观察组（B超定位）51 例,对照组（传统方法）46例。观察组采取线性高频B超探头纵横十字交叉法定位。探及骶裂孔后,将纵置的探头下部置于骶裂孔上方,采用声场内平面技术,将注射针头经超声探头下缘,与皮肤呈45°角缓慢进针。根据超声实时显像图像,引导和调整穿刺方向及深度,直至针尖完全位于骶管腔中。对照组采取传统体表定位法穿刺。结果观察组一次穿刺成功率、血管损伤率、穿刺次数及穿刺时间与对照组比较,差异有统计学意义（p <0.05）。观察组1 例穿刺失败,是因为初次实施B超定位穿刺时,未注意避开静脉丛,导致血管损伤。结论B 超引导下骶管麻醉,不但大大提高穿刺成功率,而且节约操作时间,减少穿刺次数,减少血管损伤并发症,有很好的临床推广应用价值。     

Dyslexia and across-hands finger localization deficits

Two experiments on finger localization are reported. Experiment 1 compared children who were poor readers with two groups of children matched to poor readers for sex and either age (CA controls) or reading age (RA controls). The participant's hands were kept out of his or her sight in a semi-open box while the fingers of one hand were lightly touched by the experimenter. The participant's task was to indicate, using the thumb of either the same hand (within-hand condition) or the opposite hand (across-hands condition) to respond, the finger(s) which had been touched by the experimenter. Performance was significantly impaired in the across-hands condition compared with the within-hand condition. Experiment 2 was carried out with dyslexic adults and a control group of normal readers. Using the same method of responding as in Experiment 1, a significant deficit in the across-hands condition compared to the within-hand condition was found for both groups. The effect was also obtained for both groups when participants were required to point to the relevant fingers on a photograph of a hand rather than use the thumb of the opposite hand to respond. The results are discussed in relation to the hypothesis of a deficit in inter-hemispheric transfer of tactile information in dyslexia.     

Generic head models for atlas-based EEG source analysis

We describe a method for using a generic head model, in the form of an anatomical atlas, to produce EEG source localizations. The atlas is fitted to the subject by a nonrigid warp using a set of surface landmarks. The warped atlas is used to compute a finite element model (FEM) of the forward mapping or lead-fields between neural current generators and the EEG electrodes. These lead-fields are used to localize current sources from the subject's EEG data and the sources are then mapped back to the anatomical atlas. This approach provides a mechanism for comparing source localizations across subjects in an atlas-based coordinate system, which can be used in the large fraction of EEG studies in which MR images are not available. The Montreal brain atlas was used as the reference anatomical atlas and 10 individual MR volumes were used to evaluate the method. The atlas was fitted to each subject's head by a thin-plate-spline (TPS) warp. The spatial locations of a generic 155-electrode configuration were used to constrain the warp. For the purposes of evaluation, dipolar sources were placed on the inner cortical surface in the atlas geometry and transferred to each subject's brain space using a polynomial warp. The parameters of the warp were computed using an intensity-based matching of the atlas and subject brains, thus ensuring that the sources were placed at approximately the same anatomical location in each case. Data were simulated in the subject geometry and a dipole fit was performed on these data using an FEM of the TPS warped atlas. The source positions found in the warped atlas were transferred back to the original atlas and compared to the original position. Sources were simulated at 972 locations evenly distributed over the inner cortical surface of the atlas. The mean error over all 10 subjects was 8.1 mm in the subject space and 15.2 mm in the atlas space. In comparison, using an affine transformation of the electrodes into atlas space and an FEM model generated from the atlas produced mean errors of 22.3 mm in subject space and 19.6 mm in atlas space. With a standard three-shell spherical model the errors were 27.2 mm in the subject space and 34.7 mm when mapped to atlas space.     

Immunolocalization of the Ca2+-activated K+ channel Slo1 in axons and nerve terminals of mammalian brain and cultured neurons

Ca(2+)-activated voltage-dependent K(+) channels (Slo1, KCa1.1, Maxi-K, or BK channel) play a crucial role in controlling neuronal signaling by coupling channel activity to both membrane depolarization and intracellular Ca(2+) signaling. In mammalian brain, immunolabeling experiments have shown staining for Slo1 channels predominantly localized to axons and presynaptic terminals of neurons. We have developed anti-Slo1 mouse monoclonal antibodies that have been extensively characterized for specificity of staining against recombinant Slo1 in heterologous cells, and native Slo1 in mammalian brain, and definitively by the lack of detectable immunoreactivity against brain samples from Slo1 knockout mice. Here we provide precise immunolocalization of Slo1 in rat brain with one of these monoclonal antibodies and show that Slo1 is accumulated in axons and synaptic terminal zones associated with glutamatergic synapses in hippocampus and GABAergic synapses in cerebellum. By using cultured hippocampal pyramidal neurons as a model system, we show that heterologously expressed Slo1 is initially targeted to the axonal surface membrane, and with further development in culture, become localized in presynaptic terminals. These studies provide new insights into the polarized localization of Slo1 channels in mammalian central neurons and provide further evidence for a key role in regulating neurotransmitter release in glutamatergic and GABAergic terminals.     

Radioactive seed localization of breast lesions: an adequate localization method without seed migration

Preoperative localization is important to optimize the surgical treatment of breast lesions, especially in nonpalpable lesions. Radioactive seed localization (RSL) using iodine-125 is a relatively new approach. To provide accurate guidance to surgery, it is important that the seeds do not migrate after placement. The aim of this study was to assess short-term and long-term seed migration after RSL of breast lesions. In 45 patients, 48 RSL procedures were performed under ultrasound or stereotactic guidance. In the first 12 patients, the lesion was localized with two markers: an iodine-125 seed and a reference marker. In 33 patients, 36 RSL procedures were performed using a single iodine-125 seed. All patients received control mammograms after seed placement and prior to surgery. In the patients with two markers, migration was defined as the difference in the largest distance between the markers observed in the mammograms. For single-marked lesions, migration was assessed by comparing distances between anatomical landmarks in the mammograms. RSL was successful in all patients. Seeds were in-situ for 59.5 days on average (3-136 days). The detection rate during surgery was 100%. Overall, an average seed migration of 0.9 mm (standard deviation 1.0 mm) was observed. Neither differences in lesion type, nor days in situ, type of surgery or radiologic localization method were found to have impact on seed migration. RSL is an accurate preoperative localization method for breast lesions with negligible seed migration, independent of time in-situ.     

男性生殖道感染标本采集和细菌定位培养改良法

目的:改良男性生殖道感染标本采集和细菌定位培养法,探讨标本采集和病原体分离对前列腺炎诊断与治疗的影响。方法:分别采集200例前列腺炎样症状患者的分段尿液、前列腺按摩液(EPS)和精液标本,定量接种培养液分离培养,根据分离物的菌落数及分布规律评估其实验室诊断意义。结果:从200例前列腺炎样症状患者检出病原体468株,包括细菌414株(占88.5%)、真菌12株(占2.6%)、支原体40株(占8.5%)、衣原体2株(占0.4%)。其中仅从EPS分离到病原体的患者为66例(占33.0%),仅从精液分离到病原体的患者为34例(占17.0%),EPS和精液均分离到病原体的患者为100例(占50.0%)。在这些标本中仅分离到1种病原体的分别为EPS 36例(占18.0%),精液20例(占10.0%),EPS和精液39例(占19.5%);分离到2种病原体的分别为EPS 30例(占15.0%),精液14例(占7.0%),EPS和精液60例(占30.0%);1例从EPS和精液分离到3种病原体(占0.5%)。结论:复数菌感染(MMI)、多器官感染(MOI)和耐药性菌株感染在前列腺炎样症状患者常见,是造成临床及实验室诊断漏诊和误诊的常见因素以及影响治疗效果的重要机制,MMI和MOI可通过标本采集和细菌定位培养改良法进行诊断与鉴别诊断。