Autoradiographic plaques for the detection of antibody formation to soluble proteins by single cells

Single cells that synthesize antibody to soluble proteins can be detected and counted by an autoradiographic procedure. The method is based on the specific binding of I(131)-labeled antigen to the antidogy which has been produced by and has diffused around cells in an agarose medium and which has been precipitated by an antibody to gamma globulin. The antigen-binding zones appear as dark spots on high-speed x-ray film exposed to the dried agarose preparations.     

Comment on "Preindustrial to modern interdecadal variability in coral reef pH"

Based on the boron isotopic composition of coral from the southwestern Pacific, Pelejero et al. (Reports, 30 September 2005, p. 2204) suggested that natural variations in pH can modulate the impact of ocean acidification on coral reef ecosystems. We show that this claim cannot be reconciled with other marine carbon chemistry constraints and highlight problems with the authors' interpretation of the paleontologic data.     

猪CD127流式单克隆抗体的研制

[目的]研制出猪CD127(调节因子IL-7受体α链)流式单克隆抗体,为研究分析猪淋巴细胞亚群,尤其是猪Treg细胞亚群提供流式细胞分析抗体,也为进一步探究猪抗病性状与免疫机制间的关系打下基础.[方法]克隆猪CD127基因片段,通过原核载体诱导表达出相应的融合蛋白,以纯化后的融合蛋白免疫Balb/c小鼠,然后取其脾细胞与SP2/0骨髓瘤细胞融合,综合ELISA和流式细胞仪检测筛选出亚克隆抗体,并采用Western blotting验证所得亚克隆抗体能否与猪淋巴细胞上的CD127特异性结合.[结果]猪CD127基因cDNA全长1999 bp,第49~1428 bp为开放阅读框(ORF),编码459个氨基酸,其中前21位氨基酸为信号肽,成熟肽N端第1~219位氨基酸为胞外蛋白,第220~242位氨基酸为跨膜蛋白,第243~459位氨基酸为胞内蛋白.以pET28a和pET32a原核载体诱导表达CD127胞外片段可获得大小介于34~43 kD的融合蛋白,经Ni亲和层析柱纯化后用于免疫Balb/c小鼠,6只免疫小鼠血清中的多克隆抗体均能对猪淋巴细胞中的CD3阳性细胞(CD3+)进行共标记,其中以M2和M4两只免疫小鼠抗血清对CD3+的共标记效果较优,分群清晰;但流式细胞仪检测发现,仅2.3%的CD3+能与M2混合池培养基上清液中的分泌抗体共标记,而67.0%的CD3+能与M4混合池培养基上清液中的分泌抗体共标记,且分群清晰.从M4混合池中筛选出6株效价稳定的亚克隆细胞株(1E2、1D8、2F3、2F8、3C6和4E1),且以1D8、2F3、2F8和3C6亚克隆抗体标记的CD3+较多,其培养基上清液中的分泌抗体在猪胸腺和肌肉样品中均能检测出大小约50 kD的单一目的条带.[结论]制备获得的猪CD127流式单克隆抗体可与T淋巴细胞表面的IL-7受体特异性结合,同时在流式细胞仪检测过程中可用于猪Treg细胞亚群检测.     

Specific inhibition of plaque formation to phosphorylcholine by antibody against antibody

Spleen cells from BALB/c mice immunized with heat-killed rough pneumococci (strain R36A) or spleen cells from normal mice immunized in vitro with the same antigen produce direct hemolytic plaques against sheep erythrocytes coated with pneumococcal C polysaccharide or conjugated with phosphorylcholine. Formation of plaques is specifically inhibited by phosphorylcholine or by antiserum to mouse immunoglobulin A myeloma protein which binds phosphorylcholine. Thus, the myeloma proteins and normal BALB/c antibodies share similar idiotypic determinants. This experimental system is suitable for probing the role of the antigen receptor in the immune response.     

文化因素对中介语可变性的影响

中介语的可变性是第二语言习得中一个重要而又颇具争议的话题。中介语具有可变性,这种可变性常表现为系统可变性和非系统可变性两种,其主要区别在于语言的变化是否有规律可循。由文化因素而引起的中介语变异是有规律的,是可以解释和预测的。不同文化背景下的学习者的学习风格和思维模式不同,容易导致习得规则和顺序的不同。研究中介语的系统可变性对语言教学具有指导意义。     

On biochemical variability and innovation

Examples of variability and apparent innovation presented in this paper are but a portion of the many examples in the literature. Thus, the notion of the "unity of biochemistry" has been advanced in an overly simplified form and reflects a primitive stage in the development of the discipline. Cells contain many more compounds and biosynthetic mechanisms than we had suspected or list in our texts. Accordingly, either early chemical evolution was far more extensive than we have postulated or an evolution of biochemical synthesis and function took place which was more extensive than has been postulated; perhaps both have occurred. The chemical choices available from the environment have been considerable rather than limited and the cells have chosen, adapted, improved upon a limited number of these, and in turn have themselves been selected. In the case of the naturally occurring antibiotic substances, biosynthetic mechanisms for compounds which do not fit within the cells' own nucleic acids and proteins to advantage have nevertheless been preserved since they contribute to survival. On the other hand, some of these compounds such as alpha-ribazole, are fitted to other metabolic uses. The existence of the large number of uncommon relatives of the common components of the nucleic acids and proteins in turn implies an enormous untapped area of potential knowledge concerning their paths of biosyntheses and the genetic and physiological controls for these same paths. That these compounds exist perhaps also indicates an expanded material basis for a continuing biochemical evolution.     

“灭螨A烟雾剂”的研究

“灭螨 A 烟雾剂”系采取由蜂箱外向蜂群内喷烟治螨,因此不开箱,不提脾,操作简便.工效高。它对蜜蜂安全,灭螨效果达74.7～100%。“灭螨 A 烟雾剂”与“杀螨剂一号”相比,小蜂螨的落螨数两者无显著差异,防治大蜂螨后者效果较好,但前者比后者提高工效25～30倍。与“Folbex VA”烟雾剂比较,大蜂螨的落螨数无显著差异,小蜂螨的落螨数差异显著,“灭螨 A 烟雾刘”明显优于“Folbex VA”。     

西瓜品种资源亲缘关系的同工酶分析

对３２个国内外西瓜品种（栽培、半栽培和野生种）的亲缘关系，进行了过氧化物酶同工酶和酯酶同工酶的分析．结果表明：过氧化物酶同工酶和酯酶同工酶在不同的品种类型、不同部位差异明显；用衰老部位过氧化物酶同工酶和生长活跃部位酯酶同工酶分析亲缘关系效果较好；亲缘关系相差愈远酶谱差异愈大，野生品种同工酶谱带数多干栽培品种，其中的２８个有代表性品种根据老叶过氧化物酶同工酶可聚成８个种类。     

Sleep disorders: disorders of arousal? Enuresis, somnambulism, and nightmares occur in confusional states of arousal, not in "dreaming sleep"

In summary, the classical sleep disorders of nocturnal enuresis, somnambulism, the nightmare, and the sleep terror occur preferentially during arousal from slow-wave sleep and are virtually never associated with the rapid-eye-movement dreaming state. Original data are reported here which indicate that physiological differences from normal subjects, of a type predisposing the individual to a particular attack pattern, are present throughout the night. The episode, at least in the case of enuresis, appears to be simply a reinforcement of these differences to a clinically overt level. A number of features are common to all four sleep disorders. These had been shown previously to be attributable to the arousal itself. New data obtained by means of evoked potential techniques suggest that these common symptoms of the confusional period that follows non-REM sleep are related to alterations of cerebral reactivity, at least of the visual system. The symptoms which distinguish the individual attack types (that is, micturition, prolonged confusional fugues, overt terror) appear to be based upon physiological changes present throughout sleep which are markedly accentuated during arousal from slow-wave sleep. These changes may in some way be related to diurnal psychic conflicts. But, to date, it has proved impossible to demonstrate potentially causal psychological activity, dreaming or other forms of mental activity, or even a psychological void in sleep just preceding the attacks. The presence of all-night or even daytime predisposing physiological changes and the difficulty in obtaining any solid evidence of a preceding psychological cause explain, no doubt, why the results of efforts to cure the disorders at the moment of their occurrence (for example, by conditioning procedures in nocturnal enuresis) have been far from satisfactory. I stress the points that the attacks are best considered disorders of arousal and that the slow-wave sleep arousal episode which sets the stage for these attacks is a normal cyclic event. Indeed it is the most intense recurrent arousal that an individual regularly experiences. The most fruitful possibilities for future research would appear to be more detailed studies of those physiological changes that predispose individuals to certain types of attacks when they undergo intense arousal or stress; the reversal of these changes by psychological or pharmacological means; and more refined investigations of the physiological and psychological characteristics of the process of cyclic arousal from non-REM sleep.     

Protein displacement by DExH/D "RNA helicases" without duplex unwinding

Members of the DExH/D superfamily of nucleic acid-activated nucleotide triphosphatases are essential for virtually all aspects of RNA metabolism, including pre-messenger RNA splicing, RNA interference, translation, and nucleocytoplasmic trafficking. Physiological substrates for these enzymes are thought to be regions of double-stranded RNA, because several DExH/D proteins catalyze strand separation in vitro. These "RNA helicases" can also disrupt RNA-protein interactions, but it is unclear whether this activity is coupled to duplex unwinding. Here we demonstrate that two unrelated DExH/D proteins catalyze protein displacement independently of duplex unwinding. Therefore, the essential functions of DExH/D proteins are not confined to RNA duplexes but can be exerted on a wide range of ribonucleoprotein substrates.     

水稻2种栽培方式的经济效益分析

[目的]比较水稻机器旱直播（旱直播）和旱育秧机器插秧（机插秧）2种栽培方式的经济效益。[方法]在一般栽培条件下进行水稻测产,对采用旱直播和机插秧2种栽培方式农户水稻生产的栽培成本、经济效益进行考察,分析其优劣。[结果]机插秧水稻产量远超过旱直播水稻。旱直播水稻产量相当不稳定,最高单产是最低单产的176%;而机插秧水稻最高单产是最低单产的133%。机插秧成本低于旱直播成本,旱直播稻的化学除草比机插秧多1次,不仅增加了生产成本,而且加重了除草剂对环境的污染。机插秧水稻经济效益高于旱直播水稻。[结论]水稻旱直播栽培既不省工也不省成本,更不能增收。在具有机器插秧条件的地区,应该限制水稻旱直播,推广机插秧。     

无核雪柑与普通雪柑种胚发育过程蛋白质的差异

采用考马斯亮蓝G 250法测定胚胎蛋白质含量,并用双向电泳技术分析胚胎的特异蛋白质。结果表明:无核雪柑种胚早期的蛋白质含量相对较高,其胚胎不同发育阶段出现了P1~P6 6个特异蛋白质;另外发现了4个特异于普通雪柑胚胎发育的蛋白质P11~P14。认为P11~P14与无核雪柑的无核密切相关,分别是P11(67.0 kD,pI 5.1)、P12(65.5 kD,pI 5.4)、P13(97.0 kD,pI 5.8)及P14(64.3 kD,pI 5.9)。     

Purification and reconstitution of chloride channels from kidney and trachea

Chloride channels mediate absorption and secretion of fluid in epithelia, and the regulation of these channels is now known to be defective in cystic fibrosis. Indanyl-oxyacetic acid 94 (IAA-94) is a high-affinity ligand for the chloride channel, and an affinity resin based on that structure was developed. Solubilized proteins from kidney and trachea membranes were applied to the affinity matrix, and four proteins with apparent molecular masses of 97, 64, 40, and 27 kilodaltons were eluted from the column by excess IAA-94. A potential-dependent 36Cl- uptake was observed after reconstituting these proteins into liposomes. Three types of chloride channels with single-channel conductances of 26, 100, and 400 picosiemens were observed after fusion of these liposomes with planar lipid bilayers. Similar types of chloride channels have been observed in epithelia.     

Escherichia coli secretion of an active chimeric antibody fragment

A chimeric mouse-human Fab protein that binds specifically to the human carcinoma cell line C3347 has been expressed and secreted from Escherichia coli. This molecule, which contains functionally assembled kappa and Fd proteins, binds as effectively to sites on the surface of C3347 cells as Fab fragments prepared proteolytically from whole chimeric or mouse antibody. The production in Escherichia coli of foreign heterodimeric protein reagents, such as Fab, should prove useful in the management of human disease.     

从“营造生态”到“需求驱动”:学术图书馆如何满足人文学者的数字学术需求

[目的/意义]“营造生态”和“需求驱动”是学术图书馆满足人文学者的数字学术需求、构建数字人文服务体系的两个核心关键词。这两者要求我们从宏观的业态视角理解图书馆的数字人文服务策略,进而从学理层面探寻构建数字人文生态的可行路径。[方法/过程]文章基于课题组的前期积累和相关案例,探讨构建数字人文生态的必要性和可能性。[结果/结论]文章的主要结论包括：（1）强调要尊重客观规律和客观现实,将“数字人文生态”的构建视为数字人文工作首要目标;（2）提出要理清人文学者不同类型的数字学术需求,根据需求展开学术图书馆的类型学研究;（3）学术图书馆可以划分为引领型学术图书馆、支撑型学术图书馆和基础型学术图书馆,应当推动不同类型学术图书馆在数字学术生态中各司其职,对接人文学者不同的需求,在有差异化的服务和合作中构建数字人文生态。     

荣昌猪与新荣昌猪Ⅰ系遗传变异的RAPD标记分析

利用60个随机引物对荣昌猪与新荣昌猪Ⅰ系的基因组DNA进行RAPD分析,其中35个引物可扩增出清晰的RAPD带型,1个引物A1表现出明显的遗传多态性。结果表明：荣昌猪和新荣昌猪Ⅰ系群内平均相似系数分别为0．787,0．80;平均遗传距离为0．213,0．198,两品系间平均相似系数为0．795;平均遗传距离为0．206,两品系内及品系间都存在着DNA分子水平上的差异。     

农业技术推广服务体系的“多元”与“秩序”——基于农技服务商品属性分类的分析

将所有农业技术推广服务都视为具有完全相同属性的一个"黑匣子",不对其进行更为细致地分类,会降低相关研究结论的指导性。不同类型农技服务的商品属性不同,不同地域农技服务的特点也有一定差异,类型与推广主体的匹配度对推广效率有重要影响。当前农技推广的主体和受体都很多,看似很"乱",实则不然。文章认为农技服务体系正在逐步走向多元化的有序发展阶段,基于农技服务不同属性的分类,构建类型与主体相匹配的多元化农技推广服务体系,既符合当前我国农业发展需求,也具有较强的可操作性。     

"Blow" of the pilot whale

A captive pilot whale emptied as much as 88 percent of lung gas passively, without the aid of expiratory muscles. Level or decreasing pressures in the esophagus during expiration, and in the blowhole at the onset of expiration, revealed the driving force of expiration to be solely elastic recoil. Active muscular reexpansion of the lungs ensued immediately. Expiration and inspiration were completed in about I second.     

苹果品种/类型的毛细管区带电泳法鉴别

以金冠、新红星、富士、新陆奥、乔纳金、青森、山荆子等7个苹果品种/类型为试材,应用毛细管区带电泳的方法对其水溶性蛋白质进行分析,成功地对7个不同苹果品种/类型进行了区分,说明毛细管区带电泳法可以用于苹果品种的鉴别,且方法简便、快速、高效。