多巴胺D3受体(D3R)的神经科学新进展

多巴胺(DA)是脑内一种重要的神经递质,通过不同DA受体亚型调控运动功能、认知活动和药物成瘾等生理、病理过程。多巴胺D3受体(D3R)属于D2样受体,但其功能长期不明。近年来,人们对它在神经科学中的意义有了新的认识。首先,D3R的信号通路独特,它被激活后显示细胞增殖效应,但cAMP信号传导途径不明显。其次,D3R基因敲除小鼠研究提示,正常生理状态下D3R仅表现辅助功能：在特定病理条件下,D3R显示出重要的“平衡缓冲作用”,在精神分裂症、帕金森病(PD)治疗中运动障碍副作用LID的发生和毒品复吸等病理过程扮演了重要角色。因此,D3R是一个重要的药物靶标。D3R拮抗剂在精神分裂症治疗中显示了临床前景,D3R激动剂则对PD治疗和毒品复吸防治展示了应用价值。     

3D之恐龙特展

霸王龙 霸王龙又名暴龙,是一种大型的肉食性恐龙,身长约13米,体重约7公吨,生存于白垩纪末期。化石分布于北美洲的美国与加拿大西部。     

3D之恐龙特展

霸王龙霸王龙又名暴龙,是一种大型的肉食性恐龙,身长约13米,体重约7公吨,生存于白垩纪末期。化石分布于北美洲的美国与加拿大西部。     

3D打印隐形矫牙器

上海市第十人民医院应用3D打印技术开发隐形矫牙器进行矫正畸牙。近年来,越来越多的青少年饮食过于精细,恒牙在萌出和发育的过程中缺乏富含纤维素食物的“历练”,出现了牙列不齐的问题,要想拥有一口皓齿,只能借助口腔矫正。     

3D Genome Tuner： Compare Multiple Circular Genomes in a 3D Context

Circular genomes, being the largest proportion of sequenced genomes, play an important role in genome analysis. However, traditional 2D circular map only provides an overview and annotations of genome but does not offer feature-based comparison. For remedying these shortcomings, we developed 3D Genome Tuner, a hybrid of circular map and comparative map tools. Its capability of viewing comparisons between multiple circular maps in a 3D space offers great benefits to the study of comparative genomics. The pro...     

Transformation of vitamin D3 to 1α,25-dihydroxyvitamin D3 via 25-hydroxyvitamin D3 using Amycolata sp. strains

To enzymatically synthesize active metabolites of vitamin D₃, we screened about 500 bacterial strains and 450 fungal strains, of which 12 strains were able to convert vitamin D₃ to 1,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃] via 25-hyroxyvitamin D₃ [25(OH)D₃]. The conversion activity was only detected in strains belonging to the genus Amycolata among all the organisms tested. A preparative-scale conversion of vitamin D₃ to 25(OH)D₃ and 1,25(OH)₂D₃ in a 200-1 tank fermentor using A. autotrophica FERM BP-1573 was accomplished, yielding 8.3 mg 25(OH)D₃/l culture and 0.17 mg 1,25(OH)₂D₃/l culture. A related compound, vitamin D₂, could be also converted to 25-hydroxyvitamin D₂ and 1,25-dihydroxyvitamin D₂ using the same strain. The cytochrome P-450 of FERM BP-1573 was detected by reduced CO difference spectra in whole-cell suspensions. Vitamin D₃ in the culture induced cytochrome P-450 and the conversion activity simultaneously, suggesting that the hydroxylation at C-25 of vitamin D₃ and at C-1 of 25(OH)D₃ originates from cytochrome P-450.Correspondence to: J. Sasaki     

麦迪逊展示实时3D彩超

6月12～12日,由世界超声医学与生物学联合会、中华医学会超声医学分会联合主办的“WFUMB 2005超声医学学术研讨会”在广州举行。     

干细胞3D支架的研究进展

干细胞是一类具有无限增殖潜能,可自我更新的细胞,不同的培养或诱导条件下能够分化成为不同的细胞类型。目前,随着医学治疗手段及干细胞研究的不断发展,发现干细胞可应用于很多疾病的治疗,干细胞临床应用日益广泛,逐渐成为科研工作者研究的热点。然而干细胞移植进入生物体后繁殖效率很低,无法达到需求的量,因此如何对干细胞在生物体外进行大量培养扩增、在生物体内如何更稳定地增殖分化成为迫切需要解决的难题。当前干细胞最主要的培养方法仍是2D培养,2D培养无法模拟体内的3D微环境,繁殖效率较低,正是由于2D培养局限性太多,促使国内外学者对3D培养技术和3D支架材料进行深入探索,并取得了大量成果。对3D培养技术在干细胞中的发展与应用进行概述和展望。     

3D复原应用于古生物学的初探

目前国际上流行的3D复原,其实质是将科学和艺术这两各自独立的领域予以融合,让科学的理念与现代的技术接轨并以艺术形式体现。就古生物学研究而言,逐渐流行的3D复原技术不仅能让古生物学家对其研究的对象获得更为丰富、生动的视觉效果,更为重要的是让传统平铺直叙研究所涉及的、早已消失的远古生命,能在公众心中留下鲜活记忆。文中以产自云南早寒武世的冠群甲壳动物滇彝虾(Yicaris dianensis)为例,着重介绍了3D复原的流程,包括如何从化石图片获取有用信息,进而在软件里确立草图、建出模型、赋予纹理材质,以便最终创立动画。诚然,以往许多文献资料上都附有复原图,但它们多是二维的。利用本文介绍的方法复原出来的模型,不仅能转化成经典的二维图件用于研究论文和科普读物,还可应用于影视动画,甚至在电子游戏中得以发展(如带科普性质的古生物游戏)。事实证明3D复原技术也是古生物学研究的一得力手段,值得尝试推广。     

利用猪皮凝胶进行3D细胞培养

<正>组织细胞在培养基通常是平面生长。为了更好的模拟真实的生物组织,了解细胞之间的相互关系,多年来很多实验室开展了3D细胞培养技术研发。而一些3D培养的细胞已经用于药物筛选和组织再生等方面。本研究则以猪皮为材料制作培养基,利用它富含细胞生长的营养和支持结构以及它的溶胶与凝胶的特点实施3D细胞培养。猪皮凝胶的基本制作方法如下:新鲜猪皮洗净后,在开水中煮沸5min,使皮肤与皮下组织脂肪之间的     

Disaccharide conformational maps: 3D contours or 2D plots?

The potential energy surfaces of several alpha-(1-->3)- and beta-(1-->4)-linked disaccharides were obtained and plotted in terms of energy versus psi glycosidic angle. These plots were compared to those obtained previously in the way of the usual 3D contour maps, which relate the energy with the two glycosidic angles (phi and psi). Given the usually small variations of the phi angle in the low-energy regions (at least using MM3), both kinds of graphs lead to similar conclusions concerning flexibility measurements by two different methods and assessment of the effects of sulfation and/or hydroxyl group orientation. Only second-order effects were found with some sulfated disaccharides, not changing the general conclusions. The computational efforts required to produce those plots are smaller, and the plots are easier to interpret. Besides, the conversion of a 3D map into a 2D plot leaves the possibility of constructing 3D maps of carbohydrates including a second variable different to phi, e.g., the second psi angle of a trisaccharide or the omega angle of a 6-linked disaccharide.     

利用改进的3DMax算法重构染色体3D结构

近年来,随着高通量染色体构象捕获(Hi-C)等技术的发展和高通量测序成本的降低,全基因组交互作用的数据量快速增长,交互作用图谱分辨率不断提高,促使染色体和基因组三维结构建模的研究取得了很大进展,已经提出了几种从染色体构象捕捉数据中构建单个染色体或整个基因组结构的方法。文中通过对在 Hi-C 数据基础上对染色体三维结构重建的相关文献进行分析,总结了重建染色体三维空间结构的经典算法3DMax的原理,并且提出了一种新的随机梯度上升算法:XNadam,是Nadam优化方法的一个变体,将其应用于3DMax算法中,以便提高3DMax算法的性能,从而用于预测染色体三维结构。     

柯萨奇病毒B3型3D蛋白抗体的制备

肠道病毒3D蛋白是其RNA聚合酶。柯萨奇病毒B3型(coxsackievirus B3,CVB3)主要感染心脏,其3D蛋白在心肌表达中的时序和分布尚不清楚。本研究将通过聚合酶链反应(polymerase chain reaction,PCR)获得的CVB 3D片段插入pET28a(＋)的表达框,获得pET28a(＋)-3D重组质粒。异丙基 β-D-硫代半乳糖苷(isopropyl β-D-1-thiogalactopyranoside,IPTG)诱导pET28a(＋)-3D表达3D-His蛋白,十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate-polyacrylamide gel electrophoresis,SDS-PAGE)后,切胶,获得3D-His蛋白。3D-His蛋白加佐剂免疫新西兰大白兔制备3D蛋白多克隆抗体,蛋白免疫印迹法检测抗体效价及特异性。结果显示,本研究获得了高效价且特异性好的抗CVB3 3D蛋白抗体,可用于CVB3 3D蛋白功能的后续研究。     

Analysis of forearm rotational motion using biplane fluoroscopic intensity-based 2D–3D matching

Measuring three-dimensional (3D) forearm rotational motion is difficult. We aimed to develop and validate a new method for analyzing 3D forearm rotational motion. We proposed biplane fluoroscopic intensity-based 2D–3D matching, which employs automatic registration processing using the evolutionary optimization strategy. Biplane fluoroscopy was conducted for forearm rotation at 12.5 frames per second along with computed tomography (CT) at one static position. An arm phantom was embedded with eight stainless steel spheres (diameter, 1.5 mm), and forearm rotational motion measurements using the proposed method were compared with those using radiostereometric analysis, which is considered the ground truth. As for the time resolution analysis, we measured radiohumeral joint motion in a patient with posterolateral rotatory instability and compared the 2D–3D matching method with the simulated multiple CT method, which uses CTs at multiple positions and interpolates between the positions. Rotation errors of the radius and ulna between these two methods were 0.31 ± 0.35° and 0.32 ± 0.33°, respectively, translation errors were 0.43 ± 0.35 mm and 0.29 ± 0.25 mm, respectively. Although the 2D–3D method could detect joint dislocation, the multiple CT method could not detect quick motion during joint dislocation. The proposed method enabled high temporal- and spatial-resolution motion analyses with low radiation exposure. Moreover, it enabled the detection of a sudden motion, such as joint dislocation, and may contribute to 3D motion analysis, including joint dislocation, which currently cannot be analyzed using conventional methods.     

ExonVisualiser – application for visualization exon units in 2D and 3D protein structures

The web application oriented on identification and visualization of protein regions encoded by exons is presented. The Exon Visualiser can be used for visualisation on different levels of protein structure: at the primary (sequence) level and secondary structures level, as well as at the level of tertiary protein structure. The programme is suitable for processing data for all genes which have protein expressions deposited in the PDB database. The procedure steps implemented in the application: I) loading exons sequences and theirs coordinates from GenBank file as well as protein sequences: CDS from GenBank and aminoacid sequence from PDB II) consensus sequence creation (comparing amino acid sequences form PDB file with the CDS sequence from GenBank file) III) matching exon coordinates IV) visualisation in 2D and 3D protein structures. Presented web-tool among others provides the color-coded graphical display of protein sequences and chains in three dimensional protein structures which are correlated with the corresponding exons.

Availability

http://149.156.12.53/ExonVisualiser/     

2D与3D景观指数测定山区植被景观格局变化对比分析

植被和土地覆盖变化是环境变化的一个重要因素,同时也是引起景观和生态系统变化的重要原因。景观指数是定量分析植被和土地覆盖变化的重要研究方法之一。以滇西北高山峡谷区为案例区,比较分析传统2D景观指数和3D景观指数进行植被变化定量测定的差异。研究主要选取了基于斑块面积和周长几个常用指数来进行比较分析。研究结果表明在斑块层次上,除了分维数指数,其他指数的三维方法计算值显著地高于二维方法计算值;在类型层次上,三维的类型面积指数、平均斑块面积指数、平均最小邻近距离指数测定的变化值显著大于二维的相应指数测定变化值,但是二维和三维平均形状指数和分维指数测定的植被斑块的平均形状变化结果没有显著差异;在景观层次,只有三维的平均斑块面积和最小邻近距离指数测定的变化结果显著高于二维的平均面积和最小邻近距离指数测定的变化结果,其它指数如形状指数、分维指数、多样性指数和均一度指数等测定出两个不同时期的植被图格局变化结果均无显著差异,主要由于这些指数是采用面积和周长的对数或者比值计算得出,从而缩小了斑块表面面积与平面面积,表面周长与平面周长之间的差异。总体而言,利用二维景观指数在进行定量分析山区植被格局变化时,往往低估了其类型面积、平均斑块面积、斑块邻近距离等指数变化量,而三维景观指数得到相对较精确的变化值。     

食管鳞状细胞癌组织体外3D培养

该文将新鲜的食管鳞状细胞癌组织剪成细小的碎块,和基质胶(matrigel)混合在96孔板中进行培养。在培养2、4、6、8、10、12、14、16、18天时取出并固定、石蜡包埋、切片,进行HE染色和Ki-67、P63、P40、细胞角蛋白5/6免疫组织化学实验。HE染色显示,培养的肿瘤组织与原组织基本相同。随着培养时间的延长,组织块变得小,且肿瘤组织有萎缩和退化的现象。随体外培养时间的增加, P40和P63蛋白在肿瘤细胞中的表达变少。Ki-67蛋白在肿瘤组织中表达的强度和比率都随着培养时间的延长而减弱。综上所述,食管鳞状细胞癌的一部分特性会随着体外培养时间的延长而发生变化,所以体外培养天数越短越好。     

骨科3D打印技术临床研究的状况分析

目的 研究骨科3D打印技术临床研究状况。方法 通过文献检索,对纳入的107篇文献进行系统性综述,描述骨科3D打印技术临床研究的基本状况。结果 骨科3D打印技术临床研究对象以男性为主,主要集中在成人群体,并且研究时间主要在2007年~2012年。3D打印技术经常应用于骨科手术的复位内固定、畸形矫正、椎弓根钉置入、肿瘤切除、翻修重建、膝关节置换。结论 骨科3D打印技术仍处在初步临床发展阶段。