Optimization of biodiesel production from trap grease via acid catalysis

As a kind of waste collected from restaurants, trap grease is a chemically challenging feedstock for biodiesel production for its high free fatty acid (FFA) content. A central composite design was used to evaluate the effect of methanol quantity, acid concentration and reaction time on the synthesis of biodiesel from the trap grease with 50% free fatty acid, while the reaction temperature was selected at 95 degrees C. Using response surface methodology, a quadratic polynomial equation was obtained for ester content by multiple regression analysis. Verification experiments confirmed the validity of the predicted model. To achieve the highest ester content of crude biodiesel (89.67%), the critical values of the three variables were 35.00 (methanol-to-oil molar ratio), 11.27 wt% (catalyst concentration based on trap grease) and 4.59 h (reaction time). The crude biodiesel could be purified by a second distillation to meet the requirement of biodiesel specification of Korea.

Novel biodiesel production technology from soybean soapstock

This paper describes an attractive method to make biodiesel from soybean soapstock (SS). A novel recovery technology of acid oil (AO) from SS has been developed with only sulfuric acid solution under the ambient temperature (25 +/- 2 degrees C). After drying, AO contained 50.0% FFA, 15.5% TAG 6.9% DAG 3.1% MAG 0.8% water and other inert materials. The recovery yield of AO was about 97% (w/w) based on the total fatty acids of the SS. The acid oil could be directly converted into biodiesel at 95 degrees C in a pressurized reactor within 5 hours. Optimal esterification conditions were determined to be a weight ratio of 1 : 1.5 : 0.1 of AO/methanol/sulfuric acid. Higher reaction temperature helps to shorten the reaction time and requires less catalyst and methanol. Ester content of the biodiesel derived from AO through one-step acid catalyzed reaction is around 92%. After distillation, the purity of the biodiesel produced from AO is 97.6% which meets the Biodiesel Specification of Korea. The yield of purified biodiesel was 94% (w/w) based on the total fatty acids of the soapstock.

Flying lemurs – The 'flying tree shrews'? Molecular cytogenetic evidence for a Scandentia-Dermoptera sister clade

Background: Flying lemurs or Colugos (order Dermoptera) represent an ancient mammalian lineage that contains only two extant species. Although molecular evidence strongly supports that the orders Dermoptera, Scandentia, Lagomorpha, Rodentia and Primates form a superordinal clade called Supraprimates (or Euarchontoglires), the phylogenetic placement of Dermoptera within Supraprimates remains ambiguous. Results: To search for cytogenetic signatures that could help to clarify the evolutionary affinities within this superordinal group, we have established a genome-wide comparative map between human and the Malayan flying lemur (Galeopterus variegatus) by reciprocal chromosome painting using both human and G. variegatus chromosome-specific probes. The 22 human autosomal paints and the X chromosome paint defined 44 homologous segments in the G. variegatus genome. A putative inversion on GVA 11 was revealed by the hybridization patterns of human chromosome probes 16 and 19. Fifteen associations of human chromosome segments (HSA) were detected in the G. variegatus genome: HSA1/3, 1/10, 2/21, 3/ 21, 4/8, 4/18, 7/15, 7/16, 7/19, 10/16, 12/22 (twice), 14/15, 16/19 (twice). Reverse painting of G. variegatus chromosome-specific paints onto human chromosomes confirmed the above results, and defined the origin of the homologous human chromosomal segments in these associations. In total, G. variegatus paints revealed 49 homologous chromosomal segments in the HSA genome. Conclusion: Comparative analysis of our map with published maps from representative species of other placental orders, including Scandentia, Primates, Lagomorpha and Rodentia, suggests a signature rearrangement (HSA2q/21 association) that links Scandentia and Dermoptera to one sister clade. Our results thus provide new evidence for the hypothesis that Scandentia and Dermoptera have a closer phylogenetic relationship to each other than either of them has to Primates.

非洲爪蛙分泌型叶酸结合蛋白及NKX6.3在早期胚胎神经发育中的功能研究

叶酸是B族维生素的一员，参与体内一系列重要的生命过程包括DNA，氨基酸的合成，调控细胞周期，参与一碳单位供体循环，调节DNA,蛋白质甲基化等。叶酸的许多功能都和叶酸结合蛋白有关，体内有多种跨膜形式的叶酸结合蛋白，比如Folbp1，RFC，HCP等。以前的研究表明这些不同的叶酸结合蛋白具有不同的功能。分泌型叶酸结合蛋白是另外一类叶酸结合蛋白，在人类，小鼠，猪中都有序列报道，但是其功能却知之甚少。 我们在非洲爪蛙中鉴定出一个全新的分泌型叶酸结合蛋白并命名为Secreted Folate Binding Protein(sFBP)。在胚胎和转染细胞系中我们都证明该蛋白是分泌性的，表面等离子共振实验发现sFBP能够结合叶酸。在胚胎早期这个基因表达于粘液腺和神经板区域，神经管闭合后在神经管、粘液腺、眼睛，头部以及鳃弓都有表达。特异morpholino 阻断sFBP翻译后发现粘液腺发育异常，神经管闭合缺陷，前后体轴聚集延伸运动受到抑制，尾芽期胚胎表现出体轴缩短，无眼，小头或无头的表型。进一步研究发现显微注射sFBP morpholino 的胚胎神经板区域细胞发生凋亡，中胚层和神经外胚层的一系列粘附分子表达异常，神经细胞的正常分化也受到抑制。通过显微移植实验我们还发现抑制sFBP的翻译后，神经嵴细胞的正常分化和迁移都受到抑制。但是，显微注射叶酸及其类似物或者显微注射甲基供体S-腺苷甲硫氨酸或者亮氨酸甲基转移酶都不能挽救阻断sFBP造成的表形，由此提示sFBP可能不是通过叶酸传统的参与营养合成或者甲基化的途径发挥作用。我们发现注射sFBP morpholino可以抑制Islet-1mRNA和蛋白质的表达，Islet-1的表达区域与sFBP类似。共同注射Islet-1 mRNA和sFBP morpholino可以极大的挽救sFBP morpholino的表型。最后通过morpholino特异阻断Islet-1的表达后，我们发现其表现出与sFBP morpholino类似的粘液腺发育缺陷，神经板细胞凋亡，小头无眼的表形。由此叶酸是B族维生素的一员，参与体内一系列重要的生命过程包括DNA，氨基酸的合成，调控细胞周期，参与一碳单位供体循环，调节DNA,蛋白质甲基化等。叶酸的许多功能都和叶酸结合蛋白有关，体内有多种跨膜形式的叶酸结合蛋白，比如Folbp1，RFC，HCP等。以前的研究表明这些不同的叶酸结合蛋白具有不同的功能。分泌型叶酸结合蛋白是另外一类叶酸结合蛋白，在人类，小鼠，猪中都有序列报道，但是其功能却知之甚少。 我们在非洲爪蛙中鉴定出一个全新的分泌型叶酸结合蛋白并命名为Secreted Folate Binding Protein(sFBP)。在胚胎和转染细胞系中我们都证明该蛋白是分泌性的，表面等离子共振实验发现sFBP能够结合叶酸。在胚胎早期这个基因表达于粘液腺和神经板区域，神经管闭合后在神经管、粘液腺、眼睛，头部以及鳃弓都有表达。特异morpholino 阻断sFBP翻译后发现粘液腺发育异常，神经管闭合缺陷，前后体轴聚集延伸运动受到抑制，尾芽期胚胎表现出体轴缩短，无眼，小头或无头的表型。进一步研究发现显微注射sFBP morpholino 的胚胎神经板区域细胞发生凋亡，中胚层和神经外胚层的一系列粘附分子表达异常，神经细胞的正常分化也受到抑制。通过显微移植实验我们还发现抑制sFBP的翻译后，神经嵴细胞的正常分化和迁移都受到抑制。但是，显微注射叶酸及其类似物或者显微注射甲基供体S-腺苷甲硫氨酸或者亮氨酸甲基转移酶都不能挽救阻断sFBP造成的表形，由此提示sFBP可能不是通过叶酸传统的参与营养合成或者甲基化的途径发挥作用。我们发现注射sFBP morpholino可以抑制Islet-1mRNA和蛋白质的表达，Islet-1的表达区域与sFBP类似。共同注射Islet-1 mRNA和sFBP morpholino可以极大的挽救sFBP morpholino的表型。最后通过morpholino特异阻断Islet-1的表达后，我们发现其表现出与sFBP morpholino类似的粘液腺发育缺陷，神经板细胞凋亡，小头无眼的表形。由此我们认为sFBP结合叶酸后可能通过细胞膜上的受体传递信号，并且Islet-1可能在sFBP的下游发挥作用。 神经嵴是脊椎动物特有的一群多潜能干细胞，产生于表皮和神经板的边界，在原肠运动之后这群细胞通过表皮间充值转换从神经管背侧迁移到不同的区域，分化成不同的细胞类型，包括外周神经系统，色素细胞，软骨等。神经嵴的发生是一个多步骤多基因参与的精细调控过程。目前理论认为最初由一些分泌性信号分子又叫形态生成素比如BMP,Wnt，FGF，Notch等通过不同浓度梯度的相互作用调节一组在表皮和神经板边界的转录因子（Msx、Pax3/7、Zic1、Dlx3/5等）的表达，即边界决定。这些边界决定因子进一步在预定形成神经嵴的区域激活神经嵴特化基因比如Slug/Snail、FoxD3、Twist、Sox9/10的表达完成神经嵴的特化（Specification）。 Nkx6.3是Nkx6家族的一个转录因子，RT-PCR显示其呈现母源性表达。特异抗体显示Nkx6.3蛋白第9期在整个胚胎都表达，大部分蛋白集中在细胞核，有少部分蛋白定位于细胞膜上；神经板时期主要定位于神经嵴区域的细胞膜上。过表达Nkx6.3会影响细胞粘连分子的表达，由此干扰正常的胚胎原肠运动和Activin诱导的动物帽聚集延伸运动。显微注射Nkx6.3特异morpholino阻断其蛋白表达会抑制神经嵴的marker基因Wnt8，Fgf8，Pax3，Msx1，Zic1，FoxD3，Slug的转录，阻碍神经嵴的发育。在动物帽中单独注射Nkx6.3可以在mRNA水平上诱导Wnt8、Fgf8另一方面抑制BMP4的表达进而诱导神经嵴基因Pax3，Zic1，Slug的表达。报告基因实验也显示Nkx6.3能够激活Wnt信号而在动物帽中抑制BMP信号。Nkx6.3蛋白功能域分析发现其EH1结构域（domain）参与对Wnt8信号的激活，而EH1结构域和HD结构域之间的连接区域（linker domain）参与对FGF的激活和对BMP的抑制。进一步在动物帽和胚胎中分析发现Nkx6.3对Wnt8的激活依赖于FGF家族受体信号但是不依赖于Fgf8。有趣的是4细胞时期过表达Nkx6.3促进Fgf8和Wnt8 mRNA表达，但是抑制边界决定基因Msx1、Pax3和神经嵴特化基因Slug的转录。在32细胞时期显微注射Nkx6.3可以在内源神经嵴发生区域抑制Slug的表达，而异位却诱导Slug的mRNA。我们发现与动物帽中对BMP的调节不同，在胚胎中，过表达Nkx6.3会强烈的激活Smad1蛋白在细胞核中的表达即BMP信号被激活，高的BMP信号会抑制神经嵴的发生。另外我们发现过表达Nkx6.3在胚胎中抑制Dlx5而在动物帽中却不影响Dlx5的表达水平，Morpholino阻断Dlx5会抑制Msx1、Pax3和Slug的表达。BMP信号和Dlx5在动物帽和在整体胚胎中对Nkx6.3的不同响应可以一定程度上解释过表达Nkx6.3在2个系统中对神经嵴基因Slug相反的影响结果。

Molecular and evolutionary analyses of formyl peptide receptors suggest the absence of VNO-specific FPRs in primates

Formyl peptide receptors (FPRs) were observed to expand in rodents and were recently suggested as candidate vomeronasal chemosensory receptors. Since vomeronasal chemosensory receptors usually underwent positive selection and evolved concordantly with the vomeronasal organ (VNO) morphology, we surveyed FPRs in primates in which VNO morphology is greatly diverse and thus it would provide us a clearer view of VNO-FPRs evolution. By screening available primate genome sequences, we obtained the FPR repertoires in representative primate species. As a result, we did not find FPR family size expansion in primates. Further analyses showed no evolutionary force variance between primates with or without VNO structure, which indicated that there was no functional divergence among primates FPRs. Our results suggest that primates lack the VNO-specific FPRs and the FPR expansion is not a common phenomenon in mammals outside rodent lineage, regardless of VNO complexity.

猕猴胚胎干细胞的神经谱系分化及胶质祖细胞迁移机理研究

由于伦理和材料来源的限制，目前对灵长类早期神经发育缺乏深入地了解。与啮齿类动物相比，猕猴在遗传和生理上与人类更接近，因此猕猴胚胎干细胞(rESCs)研究具有重要的研究价值，不仅能为研究发育生物学基础理论提供良好的模型，而且可为细胞替代性治疗提供大量的供体细胞。本文以rESCs为主要研究对象，在rESCs定向分化为神经细胞的基础上着重研究神经谱系分化及调控胶质祖细胞迁移的机理。主要结论如下：1) rESCs来源的神经上皮干/前体细胞(NEPs)主要变为辐射状胶质细胞(RG)后再通过中间类型的祖细胞——神经元祖细胞(NPs)和胶质祖细胞(GPs)——分别分化为神经元和胶质细胞。同时，NEPs/RG细胞群具有早期神经管背-腹和前-后轴空间特性。NEPs/RG的维持受Notch和FGFR信号作用。此外，实验中还纯化和鉴定了猕猴胶质限定性前体细胞(GRPs)。结果表明，rESCs的神经谱系分化能够模拟体内发育过程，并与啮齿类动物早期神经谱系变化过程相似。2) 气体信号分子NO(由10μM—250μM SNP供体释放)促进rESCs来源的A2B5+/Nestin/PSA-NCAM胶质祖细胞迁移。进一步研究发现Netrin-DCC信号通路介导了NO启动的细胞迁移过程。同时，Ca2也参与调控胶质祖细胞的迁移。此外，细胞外基质和整合素α6亦可能与Netrin-DCC相互作用调控细胞迁移。结果显示，NO通过激活一个复杂的信号网络系统调控胶质祖细胞迁移。本实验的研究结果有助于揭示灵长类中枢神经系统发育的机理，同时也能为治疗神经系统退行性疾病提供阶段特异性的供体细胞。

Total Dose Radiation-Hard 0. SOI CMOS Transistors and ASIC

This paper presents the total dose radiation performance of 0. S^m SOI CMOS devices fabricated with full dose SIMOX technology. The radiation performance is characterized by threshold voltage shifts and leakage currents of transistors and standby currents of ASIC as functions of the total dose up to 500krad(Si) .The experimental results show that the worst case threshold voltage shifts of front channels are less than 320mV for pMOS transistors under off-gate radiation bias at lMrad(Si) and less than 120mV for nMOS transistors under on-gate radiation bias. No significant radiation-induced leakage current is observed in transistors to lMrad(Si). The standby currents of ASIC are less than the specification of 5μA over the total dose range of 500krad(Si).

支持JSR286规范的Portlet协作框架的设计与实现

Portlet是具有用户界面的可与用户多次交互的Web组件。随着Portal和Portlet在企业中的广泛应用，仅仅将各种应用和数据通过Portlet集成到Portal中已经不能满足用户的需求。用户希望这些应用之间能够相互协作，以利用现有应用组建新的业务流程。Portlet协作是指两个或多个Portlet进行信息交换并使用这些信息的能力。目前协作功能的实现方式可以分为两种：基于后端(back-end)的实现方式与基于前端(front-end)的实现方式。在这两种协作实现方式的基础上，本文提出了两种Portlet协作框架。 本文提出一种基于事件的Portlet前端协作模型，通过引入此模型，解决了Portlet前端协作中客户端与服务器端无法交互的困难，使协作动作由客户端和服务器端共同完成。基于此模型提供给开发者一种可扩展的协作框架，利用JavaScript技术使得协作的Portlet在客户端“相知”，协作的行为在客户端触发，Portlet获得协作数据后使用Ajax技术请求服务器端的资源，服务器端使用JSR286规范定义的资源服务接口响应用户的请求，进而动态更新界面。 当前的Portlet后端协作方式依赖于特定的Portal产品，针对这点不足，本文在JSR286规范定义的事件及共享渲染参数协作机制基础上，实现了一个Portlet后端协作框架。在该框架中协作服务使用消息队列保存待处理的消息，Portlet 容器作为中介实现发布事件的Portlet和订阅事件的Portlet之间松散耦合。Portlet监听协作事件，事件触发后调用事件协作服务发布事件，为了提高协作的并发性，事件协作服务使用多线程处理协作事件。该协作框架与JSR286规范兼容，具有良好的可移植性。 本文对这两种Portlet协作框架进行了实现，并将其应用于中科院软件所自主开发的门户产品OncePortal中。本文重构了OncePortal系统，给出了框架的体系结构与系统接口，描述了框架的各功能模块，并详细讨论了Portlet协作框架中的关键技术，包括事件协作流程的描述、事件处理过程、多级事件流等。

川西青杨组(Section Tacamahaca Spach)不同种的亲缘关系分析

青杨组（Section Tacamahaca Spach）杨树是我国重要的乡土经济树种，目前对其分子遗传变异和系统进化的研究还很少，尤其是在青杨组杨树遗传资源极为丰富的川西地区，杨树的分子进化及亲缘关系的研究极为缺乏，非常不利于该树种遗传资源的开发和利用。本研究从川西地区收集了青杨（Populus cathayana）、青海杨（P. prezewalskii）、滇杨（P. yunnanensis）、康定杨（P. kangdingensis）、西南杨（P. schneideri）、小叶杨（P.simonii）和三脉青杨（P. trinervis）这7 个青杨组树种的10 个群体，利用多种分子标记手段对其种间的亲缘关系进行比较，并结合形态和地史资料进行了全面的研究和评价，得到了如下的主要研究结果： 1. SSR 和ISSR 位点变异丰富。通过10 对引物对50 个杨树个体的DNA 样品进行了SSR 分析，所有位点展现了丰富的群体间和种间的多态性，多态位点率达到了100%，每位点的等位基因数变化范围为5 ~ 17，平均为11.9 个；通过11 条ISSR 随机引物对供试的混合DNA 样品进行分析，共检测到130 个标记，其中多态性标记为119 个，多态百分率为91.5%。研究认为，SSR 单个标记能展现高水平信息，而ISSR 单个引物能探测更多数量多态性。通过两个标记的遗传距离、聚类图和PCA 分析，表明：同一种内不同群体间的同源性最高；康定杨和西南杨有较近的亲缘关系；小叶杨和三脉青杨聚合在一起，显示了其相互较近的亲缘关系；滇杨与其它杨树种可能存在着较远的亲缘关系。 2. 采用4 对选择性引物对7 个青杨组杨树种10 个群体进行AFLP 分析，总共扩增出284 个位点，其中200 个位点显示出了多态性，多态位点百分比为70.4%，平均多态带为50 条。TE-AFLP 的分析总共扩增出192 个位点，其中139 个位点显示出了多态性，多态位点百分比为72.4%，平均多态带为34.7 条。比较的结果表明AFLP、TE-AFLP 的遗传信息含量比较接近，略小于ISSR，大约仅为SSR 的1/3；但这两个基于AFLP 的标记系统的信息探察能力也远大于ISSR 和SSR 标记系统。这两个分子标记的聚类结果，显示小叶杨、三脉青杨和滇杨三个种聚为一组，其中小叶杨与三脉青杨的亲缘关系更近；其它几个杨树种聚为一类，西南杨与青杨表现出较近的亲缘关系。 3. 所有7 对cpSSR 引物中，仅有4 个叶绿体位点在种间具有多态性，而在种内群体中并不具有多态性，共检测出13 个条带，组合成了4 种不同的单倍型；对于cpDNA的5 对引物，共检测出了73 条酶切片段，其中52 条是多态带，组合成了9 种不同的单倍型；而5 对mtDNA 通用引物未能检测出多态性的条带，表现出线粒体的保守性。叶绿体的聚类分析认为，小叶杨、三脉青杨和滇杨有较近的母性起源，且依次聚合；其余四种杨树聚为一类，并且康定杨与西南杨表现出最近的亲缘关系，并依次与青杨和青海杨聚合。 4. 根据本文的分子数据，结合形态和生境分布资料分析认为：青杨组杨树种内群体间的遗传变异程度是小于种间的遗传差异，显示了与传统分类一致的结果；三脉青杨和小叶杨有很近的亲缘关系，可能拥有相同的祖先类群；滇杨与小叶杨和三脉青杨之间具有一定的亲缘关系，特别是在其母性祖先的起源上有着一定的同源性；西南杨与青杨和康定杨均保持着较近的亲缘关系，且有可能是这两个种原始祖先杂交后所形成的。 Although western Sichuan is regarded as a natural distribution and variation center forthe Section Tacahamaca of the Populus species in China, little is currently known about themajority of poplar species occurring in this region. In the present study, molecular data wereutilized to determine the genetic relationships among Populus species in Section Tacamahacain western Sichuan including P. cathayana, P. prezewalskii, P. yunnanensis, P. kangdingensis,P. schneideri, P. simonii and P.trinervis. The results are as fellows: 1. The genetic variation at SSR and ISSR loci was abundant. All the 10 SSR loci werepolymorphic, and the number of alleles per locus varied from 5 to 17 with a mean valueequaling 11.9. Based on the 11 ISSR primers, 130 clear and reproducible DNA fragmentswere generated, of which 119 (91.5%) were polymorphic. Our results reveal that single SSRlocus can present more genetic information, while more polymorphic bands can be detectedby single ISSR primer. Moreover, the genetic distance, cluster and PCA analysisdemonstrated that: a close relationship among accessions of the same species and suggestedmonophyly in P. przewalskii and P. cathayana; P. schneideri is genetically highly similar to P.kangdingensis; P. trinervis and P. simonii have a close genetic affinity; P. yunnanensis isdistinct from the other species. 2. Genetic relationships of poplar species in Section Tacamahaca from western Sichuanwere evaluated by means of AFLP and TE-AFLP. For four AFLP primer combinations, atotal of 284 bands were obtained of which 200 (70.4%) were polymorphic with the average of50 polymorphic bands. For four TE-AFLP primer combinations, a total of 192 band wereobtained of which 139 (72.4%) were polymorphic with the average of 34.7 polymorphicbands. Our results indicate that the genetic information of AFLP is similar to that ofTE-AFLP, and little less than that of ISSR, but only about 1/3 of that of SSR. However, theability of information detection of the two AFLP-based markers is much higher than that ofISSR and SSR. In addition, the cluster analysis of AFLP, TE-AFLP and combined data revealthat: P. yunnanensis, P. trinervis and P. simonii clustered together, and P. trinervis and P.simonii showed more closed affinity; the other four poplar species clustered together, P.cathayana and P. schneideri showed more closed origin especially. 3. The cpSSR analysis for seven Populus species belonging to the Section Tacamahaca.Four out of the seven analyzed chloroplast loci were polymorphic, whereas none of the lociwere polymorphic across the accessions within a species. 13 bands and 4 different kinds ofhaplotypes were reduced. Based on 5 pairs of cpDNA primers, 73 fragments (52 polymorphic)and 9 kinds of haplotypes were produced. However, none of the polymorphic was detected bythe 5 mtDNA primer pairs, revealing conservation of mtDNA region. The cluster analysis ofcpDNA revealed that: similar maternal phylogeny among P. yunnanensis, P. trinervis and P.simonii; the other four species clustered together, P. schneideri and P. kangdingensis showedmore closed maternal lineage especially. 4. Our molecular data, morphological characters and nature habitat revealed that: sameto the traditional taxonomy assignment, genetic variation within a same Populus species islower than that among Populus species in Section Tacamahaca; P. yunnanensis may share itschloroplast ancestor with P. trinervis and P. simonii; moreover, sister genetic relationship of P.trinervis and P. simonii indicated their similar origin; P. schneideri clustered with P.kangdingensis and P. cathayana, respectively, and may have derived from an ancienthybridization event involving the ancestors of the two species.

基于分支时序逻辑的编译优化测试用例自动生成方法的研究与实现

编译器是软件产业中重要的工具，对它的质量保证非常重要。编译优化是编译器的重要功能，它的质量对于编译器质量有重大影响。可采用软件测试的方法进行编译器优化模块的质量保证。测试需要测试用例。编译优化的测试用例必须触发编译器的优化功能，是具有可被优化特征的源程序。对不同的编译优化，该特征各不相同。需要将不同优化所对应的特征加入到源程序中以构造编译优化测试用例程序。 TRANS语言结合了时序逻辑，描述了不同的编译优化，包括优化前后的代码特征、优化执行的条件及方法。优化前的代码特征和执行优化的条件可被用作构造编译优化测试用例程序所需的特征。一种基于时序逻辑的编译优化测试用例程序生成方法的框架已被提出。该方法从TRANS描述的某种变体生成编译优化测试用例程序。但是该框架并未完善，面临多方面的问题。本文参考该框架的思想，设计了编译优化测试用例程序生成方法，解决了算法框架的部分问题。该方法可以适应复杂描述的情况；公式的合法性及语义得以保持；具体化并完整化了原有框架。该方法是具有针对性的编译优化测试用例程序自动生成方法。本文对该方法作了原型系统实现，并从中得到测试用例程序。本文设计并进行针对GCC的优化模块测试实验，以覆盖率为评价指标检验了测试用例程序的质量。实验表明该方法生成的测试用例程序具有针对性。对编译优化模块的测试，该方法是一种行之有效的办法。并且该方法仍有更多的应用空间，加以改进后可用于优化组合测试、优化正确性检测等。

Preliminary study on melt-spinning, adhesion and adsorption properties of poly(lactic acid)

For the purpose of manufacturing cigarette filter tows and filter rods, the melt-spinning, adhesion and adsorption properties of poly(lactic acid) were studied. The rheological measurements were performed to examine the effects of various processing conditions on the melt flowability and spinnability, including those of residual moisture. The melt spinning and post-processings were followed by determining the molecular weight, thermal and mechanical properties of the fibers. The results obtained were useful to establishing the specification of the PLA resins for filter tows and filter rods manufacturing and to choosing proper melt-spinning and post-processing technologies.

Comparative expression analysis of transcription factor genes in the endostyle of invertebrate chordates

The endostyle of invertebrate chordates is a pharyngeal organ that is thought to be homologous with the follicular thyroid of vertebrates. Although thyroid-like features such as iodine-concentrating and peroxidase activities are located in the dorsolateral part of both ascidian and amphioxus endostyles, the structural organization and numbers of functional units are different. To estimate phylogenetic relationships of each functional zone with special reference to the evolution of the thyroid, we have investigated, in ascidian and amphioxus, the expression patterns of thyroid-related transcription factors such as TTF-2/MoxE4 and Pax2/5/8, as well as the forkhead transcription factors FoxQ1 and FoxA. Comparative gene expression analyses depicted an overall similarity between ascidians and amphioxus endostyles, while differences in expression patterns of these genes might be specifically related to the addition or elimination of a pair of glandular zones. Expressions of Ci-FoxE and BbFoxE4 suggest that the ancestral FoxE class might have been recruited for the formation of thyroid-like region in a possible common ancestor of chordates. Furthermore, coexpression of FoxE4, Pax2/5/8, and TPO in the dorsolateral part of both ascidian and amphioxus endostyles suggests that genetic basis of the thyroid function was already in place before the vertebrate lineage. (c) 2005 Wiley-Liss, Inc.

Cloning and sequence analysis of the partial sequence of the rbcL from Bryopsis hypnoides

The partial sequence of the rbcL from Bryopsis hypnoides, including the sequences of the upstream, extron and partial intron, was amplified by PCR and their sequences were determined. With Spinacia oleracea as the outgroup, neighbor-joining method and maximum parsimony method were used respectively to build phylogenetic trees according to the rbcL exon sequence among 13 species that were the typical species of six phyla. Two kinds of trees showed clearly that there were two groups among those species, the green lineage and the non-green lineage. And the relationships of algae in the green lineage were similar in the two trees but those in the non-green lineage were not consistent. Analysis of codon preference indicated that the codon preference of the rbcL exon of Bryopsis hypnoides distinctly differed from that of the relevant sequence of photosynthetic bacteria.

Amphi-Eomes/Tbr1: An amphioxus cognate of vertebrate Eomesodermin and T-Brain1 genes whose expression reveals evolutionarily distinct domain in amphioxus development

A cDNA for a novel T-box containing gene was isolated from the amphioxus Branchiostoma belcheri. A molecular phylogenetic tree constructed from the deduced amino acid sequence of the isolated cDNA indicates that this gene belongs to the T-Brain subfamily. In situ hybridization reveals that the expression is first detected in the invaginating archenteron at the early gastrula stage and this expression is down-regulated at the neurula stage. In early larvae, the expression appears again and transcripts are detected exclusively in the pre-oral pit (wheel organ-Hatschek's pit of the adult). In contrast to the vertebrate counterparts, no transcripts are detected in the brain vesicle or nerve cord throughout the development. These results are interpreted to mean that a role of T-Brain products in vertebrate forebrain development was acquired after the amphioxus was split from the lineage leading to the vertebrates. On the other hand, comparison of the tissue-specific expression domain of T-Brain genes and other genes between amphioxus and vertebrates revealed that the pre-oral pit of amphioxus has several molecular features which are comparable to those of the vertebrate olfactory and hypophyseal placode. (C) 2002 Wiley-Liss, Inc.