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981.
A new species of the genus Leptolalax is described from Doi Saket, Chiang Mai Province, northern Thailand. The new species is distinguished from its congeners by the following combination of characters: 1) adult size large(male SVL 45.8-52.5 mm); 2) tympanum distinct; 3) skin of dorsal surface mostly smooth, with distinct tubercles on dorsal and lateral parts of the body; 4) ventrolateral glandular ridge distinct and complete; 5) lateral body and groin covered with dark brown or black spots; 6) throat, chest, and belly nearly immaculate white; and 7) bi-colored iris, upper onethird golden, and lower two-thirds gray. Molecular phylogenetic analysis of mitochondrial 16S rRNA further distinguishes it from its congeners for which sequences are available. 相似文献
982.
Hyun‐Joo Lee MinSeok Chang Jong‐Mook Kim HyeJin Hong KiEun Maeng Jane Koo ShinJae Chang Myung‐Sam Cho 《Biotechnology progress》2013,29(2):432-440
Host cell lines developed by genetic engineering sometimes show instabilities in maintaining their genetically acquired phenotypes. Previously, a hybrid host cell line, designated as hybrid of kidney and B cells (HKB), capable of retaining selected phenotypes originally existing in the parental cells was developed via fusion of 293 cells and HH514‐16 cells. Although HKB did indeed successfully preserve several favorable phenotypes, the expression of Epstein‐Barr virus (EBV) specific nuclear antigen 1 (EBNA1), which should be constitutively expressed for host cells to utilize oriP expression vector in transient production of therapeutic proteins, was observed to be unstable. Here, in an attempt to obtain stable expression of EBNA1, a cell type that contains an integrated EBV genome, rather than HH514‐16 cells, which harbor an episomal EBV genome, was applied for fusion with 293 cells. Fusion of 293 cells with Namalwa cells led to the creation of a new type of hybrid, F2N, which was able to stably express EBNA1 while not producing EBV particles. One of the F2N clones, F2N78, was observed to maintain EBNA1 expression for more than 1 year under serum‐free suspension culture conditions along with human specific glycosyl phenotypes observed previously in HKB. In addition, F2N78 was demonstrated to be an appropriate host cell line for both the transient and stable production of recombinant therapeutics with the features of safety expected of production cell lines for human use. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29: 432–440, 2013 相似文献
983.
984.
This study was conducted to compare the safety of soybean meal prepared from genetically modified (GM) glyphosate-tolerant (Roundup Ready; RR) soybeans and conventional soybeans. Eighty Sprague-Dawley rats (40 males and 40 females) were randomly allotted to one of four groups according to sex and body weight for a 13-week feeding experiment. The rats were fed corn-based diets containing 60% conventional soybean meal, a mixture of 30% conventional and 30% RR soybean meal, 60% or 90% RR soybean meal. All diets were adjusted to an identical nutrient level except the 90% RR diet. The two soybean meals were similar in chemical analysis and amino acid composition. During the 13-week growth trial, body weight (P?0.05) and feed intake (P?0.05) decreased only in rats fed with 90% RR soybean meal at the first week. No treatment-related deaths occurred during the experiment. Gross necropsy findings, haematological or urinalysis values and clinical serum parameters showed no meaningful differences between rats fed the control and RR soybean meals. A 145?bp of cp4 epsps gene specific for the GM constructs from RR soybean meal or a 407?bp of lec gene from endogenous soybean DNA could not be detected in investigated masseter muscle samples. No adverse effects of glyphosate-tolerant soybean meal on rats were seen even at levels as high as 90% of the diet. 相似文献
985.
Jie Li Yu Han Ting‐Ru Jiang Jia Liu Hong‐Xia Hua Yan‐Fei Xiong Jun‐Sheng Li 《Insect Science》2013,20(6):703-716
The brown planthopper (BPH) Nilaparvata lugens is an economically important pest on rice plants. In this study, the higher population density and yellow‐ripe stage of rice plants were used to construct adverse survival conditions (ASC) against BPH nymphs. Simultaneously, the low population density and tillering stage of rice plants were used to establish a suitable survival condition (SSC) as a control. Solexa/Illumina sequencing was used to identify genes of BPH nymphs responding to ASC. Significantly longer duration development of BPH nymphs and significantly lower brachypterous ratio of BPH adults were observed by ASC compared with SSC. A total of 2 544 differentially expressed genes (DEGs) were obtained and analyzed by BLASTx, Gene Ontology and KEGG Orthology. Gene ontology analysis revealed that the DEGs were mainly involved in categories of cell, cell part, cellular process, binding, catalytic, organelle and metabolic processes. 1 138 DEGs having enzyme commission numbers were assigned to different metabolic pathways. The largest clusters were neurodegenerative diseases (137, 12.0%), followed by carbohydrate metabolism (113, 9.9%), amino acid metabolism (94, 8.3%), nucleotide metabolism (76, 6.7%), energy metabolism (64, 5.6%), translation (60, 5.3%), lipid metabolism (58, 5.1%), and folding, sorting and degradation (52, 4.6%). Expressing profile of 11 DEGs during eight nymphal developmental stages of BPH were analyzed by quantitative real‐time polymerase chain reaction. The 11 genes exhibited differential expression between ASC and SSC during at least one developmental stage. The DEGs identified in this study provide molecular proof of how BPH reconfigures its gene expression profile to adapt to overcrowding and low‐quality hosts. 相似文献
986.
987.
目的:研究小鼠下颌下腺细胞的培养方法,探讨下颌下腺细胞培养条件及细胞生长特性,为研究干细胞转分化涎腺腺泡细胞以及涎腺再生研究奠定理论基础和技术支持。方法:取2周龄的小鼠,组织块法和消化法分别进行培养,用活细胞观察法和HE染色法记录细胞形态学特征;免疫荧光染色法鉴定;通过生长曲线和细胞倍增时间来比较两种方法对细胞增殖能力的影响。结果:组织块法和消化法均可以成功的培养下颌下腺细胞,(1)组织块法培养的细胞呈卵圆形或多边形,10天左右成铺路石样;消化法培养细胞亦为上皮样细胞,呈多边形,胞质丰富;(2)HE染色下颌下腺细胞呈多边形,胞核明显;(3)Cytokeratin13和AQP5表达阳性,Wimentin表达阴性;(4)组织块法培养细胞增殖相对较平缓,消化法培养细胞增长较迅速;(5)消化法培养倍增时间(1.3471±0.6071)天比组织块法倍增时间(2.1887±1.1503)明显缩短(P〈0.05);结论:体外可以成功的培养下颌下腺细胞,但是同时证明下颌下腺细胞长期传代较困难,这为研究干细胞转分化涎腺细胞和涎腺再生体内实验提供了理论和实验基础。 相似文献
988.
目的观察苦参、当归、侧柏叶和白鲜皮及观察苦参、当归、侧柏叶和白鲜皮、混合药液与主要有效成分对4株CBS马拉色菌标准株的体外抑菌效果。方法通过液基稀释法,用含橄榄油的液体培养基测定各药液对马拉色菌的抑制作用。结果最小抑菌浓度(MIC)由小到大排列分别为:白鲜碱、苦参碱、苦参、侧柏叶、氧化苦参碱、侧柏叶+当归(二仙丸)、混合药液(侧柏叶+当归+苦参+白鲜皮)、白鲜皮、二仙丸+苦参、苦参+白鲜皮、二仙丸+白鲜皮、槲皮素、当归、阿魏酸。结论4种中草药及其混合药液、主要有效成分均有抑制马拉色菌的作用。 相似文献
989.
990.
目的:探讨磁共振多序列成像对鉴别胰头癌与胰头肿块型慢性胰腺炎的临床价值及意义。方法:对已确诊的16例胰头癌患者和5例胰头肿块型慢性胰腺炎患者的磁共振多序列成像MR进行回顾性分析。主要征象包括:①肿块信号及形态学特点;②胰管及胆管扩张情况;③动态增强的特征;④胰周及大血管受累情况;⑤邻近器官受累与淋巴结肿大情况。检查方法包括:平扫T1WI+FST2WI+FS,MRCP,3D—VIBE动态增强扫描。结果:1)肿块形态信号异常:胰头癌与胰头肿块型胰头慢性胰腺炎的信号有较多重叠,在TlwI上均表现为相对低信号,T2WI表现为不均匀稍高、相等或低信号。2)胰管与胆管的异常:胰头癌表现为胰管扩张至肿块处突然截断12例,胆总管突然截断10例,“双管征”10例。胰头肿块型慢性胰腺炎胰管扩张3例,2例为串珠样扩张,扩张的胰管可贯通病灶区,胆总管5例均扩张,远端呈短锥形狭窄3例,鼠尾样狭窄2例。3)3D—VIBE强化特征分析结果:随着时间的延长胰头癌强化程度和强化百分率较胰头肿块型慢性胰腺炎明显减低。4)胰周大血管受累情况:胰头癌肿块与血管分界不清者8例,部分包绕血管6例完全包绕血管6例;胰头肿块型慢性胰腺炎1例与血管分界不清,1例部分被包绕。5)邻近器官受累与淋巴结肿大情况:胰头癌有7例淋巴结肿大主要分布在胰周及腹主动脉旁,胰头肿块型慢性胰腺炎,未见明显肿大淋巴结,有四例肾周筋膜增厚,两例肾前筋膜增厚。结论:磁共振多序列成像的联合使用及征象分析,有助于鉴别胰头癌与胰头肿块型慢性胰腺炎。 相似文献