外源ALA对NaCl胁迫下酸枣幼苗叶绿素合成的影响

【目的】研究外源ALA对NaCl胁迫下酸枣幼苗叶绿素合成的影响。【方法】以酸枣水培幼苗为材料,研究外源ALA对NaCl胁迫下酸枣幼苗叶片内源ALA含量、胆色素原含量、原卟啉Ⅸ含量、Mg-原卟啉Ⅸ含量、原叶绿酸酯含量以及叶绿素总含量的影响。【结果】与150 mmol/L NaCl处理相比,外施100 mg/L ALA显著提高了酸枣幼苗的内源ALA含量、胆色素原含量、原卟啉Ⅸ含量、Mg-原卟啉Ⅸ含量、原叶绿酸酯含量、叶绿素a、b含量以及叶绿素总含量,较NaCl处理分别提高44.8%、20.8%、21.2%、26.4%、36.5%、36.0%、38.4%和41.2%;且叶绿素合成受阻位点在ALA向PBG转化过程。【结论】外源ALA可以促进NaCl胁迫下酸枣幼苗叶绿素的合成,促进幼苗生长。     

Zinc protoporphyrin in the erythrocytes of patients with lead intoxication and iron deficiency anemia

The fluorescent porphyrin in the erythrocytes of patients with lead intoxication or with iron deficiency anemia is zinc protoporphyrin that is bound to globin moieties, probably at heme binding sites.     

Central nervous system dysfunction due to lead exposure

Central nervous system dysfunction was investigated in workers at a secondary lead smelter by means of performance tests. Correlations between test scores and zinc protoporphyrin levels, a biological indicator of lead toxicity, are statistically significant. This correlation should prove to be useful in current efforts to evaluate effects of lead exposure.     

Significance of mitochondria for porphyrin and heme biosynthesis

It is concluded that mitochondria are involved in three steps of porphyrin and heme biosynthesis-first, in the formation of delta-aminolevulinic acid from glycine and active succinate; second, in the synthesis of protoporphyrin; third, in the incorporation of iron into the porphyrin ring-that is, in heme formation.     

Avian eggs: thermoregulatory value of very high near-infrared reflectance

Studies of the spectral reflectance of the eggs of 25 species of birds from nine families disclosed uniformly high reflectance (often above 90 percent) in the near infrared. This property is associated with the presence of the eggshell pigments protoporphyrin and the bilins. These pigments allow coloration for cryptic or other purposes with minimum solar heating, a combination not possible with the melanin pigments typical of vertebrates.     

Genetic regulation of chlorophyll synthesis analyzed with mutants in barley

Barley seedlings homozygous both for the xantha-1(35) and tigrina-d(12) mutation accumulate magnesium protopophyrins and other precursors of chlorophyllide constitutively in darkness. The homozygous double mutant xantha-f(10), tigrina-O(34) produces protoporphyrin constitutively. These results provide evidence for the control of chlorophyllide synthesis in higher plants through the products of regulatory genes in the nucleus.     

Antibody-catalyzed porphyrin metallation

An antibody elicited to a distorted N-methyl porphyrin catalyzed metal ion chelation by the planar porphyrin. At fixed Zn2+ and Cu2+ concentrations, the antibody-catalyzed reaction showed saturation kinetics with respect to the substrate mesoporphyrin IX (2) and was inhibited by the hapten, N-methylmesoporphyrin IX (1). The turnover number of 80 hour-1 for antibody-catalyzed metallation of 2 with Zn2+ compares with an estimated value of 800 hour-1 for ferrochelatase. The antibody also catalyzed the insertion of Co2+ and Mn2+ into 2, but it did not catalyze the metallation of protoporphyrin IX (3) or deuteroporphyrin IX (4). The antibody has high affinity for several metalloporphyrins, suggesting an approach to developing antibody-heme catalysts for redox or electron transfer reactions.     

基于脱氧核酶-等温级联放大耦合的传感体系高灵敏检测水样中铅离子

我们结合等温直链替代反应（SDA）和指数扩增（EXPAR）设计了一种非标记、高灵敏的Pb2+荧光生物传感体系。在 Pb2+存在情况下,底物链被活化的GR-5 DNAzyme快速切割释放引物1。引物1与模板1杂交,并被DNA聚合酶（BSM）延伸形成带限制性内切酶（Nt.BbvCI）的识别序列的双链核苷酸。BSM从Nt.BbvCI切割产生的切口再次延伸形成双链核苷酸,并释放信号G4-DNA片段。G4-DNA片段同时又可以作为模板2的引物,启动指数放大过程,从而释放更多的信号G4-DNA片段。最后,扩增产物G4-DNA与原卟啉锌(ZnPPIX)相互结合从而产生强烈的荧光信号。我们详细优化了多种因素对检测体系的影响,在最优实验条件下,此方法对Pb2+的线性检测范围为 0.1~50 nM,检出限为0.03 nM（S/N=3）,回归方程为 y=288.7x+744.7(y为荧光强度,x为Pb2+浓度)。干扰实验表明,该传感器对Pb2+具有良好的特异性和选择性。该传感体系成功应用于环境水体中 Pb2+含量检测,加标回收率为 94.0%～103.0%。本方法操作简单、选择性好、灵敏度高、有较强的抗干扰性能,可用于环境水样中Pb2+的高灵敏检测。     

Effects of Molybdenum on the Intermediates of Chlorophyll Biosynthesis in Winter Wheat Cultivars Under Low Temperature

The objective was to probe the site where the biosynthesis of chlorophyll was blocked under Mo deficiency at low temperature, which led to the decrease of chlorophyll in winter wheat cultivars. The intermediates of chlorophyll biosynthesis were analyzed in winter wheat cultivars in soil culture, miniblock culture, and solution culture to study the effects of Mo on chlorophyll biosynthesis without Mo addition （CK, soil available Mo 0.112 mg kg^-1） and Mo addition （＋ Mo, 0.13 mg kg^-1 Mo was added）. Laevulinic acid （LA）, the competitive analog of δ-aminolaevulinic acid （ALA） was also introduced in the experiment. The ratio of Chl a/Chl b was constant between CK and ＋ Mo treatment, whereas it increased at low temperature, which indicated that Mo deficiency did not inhibit the transformation of Chl a to Chl b at low temperature. Under Mo deficiency, the contents of protochlorophyll （Pchl）, Mg-protoporphyrin Ⅸ （Mg-Proto Ⅸ）, protoporphyrin Ⅸ （proto IX）, and uroporphyrinogen Ⅲ （Uro Ⅲ） decreased [Uro Ⅲ decreased significantly （P 〈0.01）], whereas ALA and glutamate increased significantly （P 〈 0.01） compared with that of Mo addition, which suggested that the transformation from ALA to Uro Ⅲ might be inhibited. The content of ALA reversed after addition of LA, it was significantly higher （P 〈 0.01） in Mo addition than in CK. The results indicated that the transformation from ALA to Uro Ⅲ was blocked under Mo deficiency, which resulted in the inhibition of the biosynthesis of chlorophyll and led to the decrease of chlorophyll in winter wheat cultivars.     

低温条件下钼对冬小麦叶绿素合成前体的影响

 【目的】探讨低温缺钼条件下冬小麦叶绿素合成受阻位点。【方法】采用土培试验、微区试验、营养液培养试验,设不施钼(CK, 土壤有效钼0.112 mg·kg-1)和施钼（+Mo, 施钼水平为0.13 mg·kg-1）处理，及δ-氨基酮戊酸(ALA)转化抑制剂乙酰丙酸（LA）处理，研究了缺钼对冬小麦品种叶绿素几种重要合成前体的影响。【结果】低温时叶绿素a与叶绿素b的比值（Chla/Chlb）上升，而不施钼时比值不变，表明低温抑制Chla 向Chlb的转化，而缺钼不影响它们的转化。叶绿素合成前体原叶绿素酸(酯)(Pchl)、镁原卟啉Ⅸ(Mg-ProtoⅨ)、原卟啉Ⅸ(protoⅨ)、尿卟啉原Ⅲ(UroⅢ)不施钼时显著下降，其中UroⅢ急剧下降，ALA、谷氨酸（Glu）显著累积，表明从Glu或ALA向UroⅢ的转化可能受阻；加入ALA转化抑制剂LA后，ALA含量逆转为不施钼小于施钼，表明缺钼条件下ALA向UroⅢ的转化受阻。【结论】缺钼影响ALA向UroⅢ的转化，导致叶绿素合成受阻，含量下降。     

Esterase 6 and reproduction in Drosophila melanogaster

A nonspecific carboxylesterase (esterase 6) of Drosophila melanogaster shows greater activity in adult males than in females and is highly concentrated in the anterior ejaculatory duct of the reproductive tract of the male. Esterase 6 is depleted in males by copulation and is transferred to females early during copulation as a component of the seminal fluid. That esterase 6 may be involved in a system controlling the timing of remating is suggested by differences in the activity of this enzyme in a strain of Drosophila selected for a decrease in time to remating and by differences in the timing of remating in females initially inseminated by males lacking or having active esterase 6.     

职务发明创造的专利申请权及专利权辨析

现行《专利法》对职务发明的规定有不合理之处，如第六条第一款“主要是利用本单位的物质技术条件所完成的发明创造为职务发明创造”与本条第三款“利用本单位的物质技术条件所完成的发明创造，单位与发明人或设计人订有合同，对申请专利的权利和专利权的归属作出约定的，从其约定”，在法律适用方面容易产生歧义；叉如将“主要是利用本单位的物质技术条件所完成的发明创造”界定为职务发明，本身就不具合理性。因此笔者建议在第三次修订专利法之时，重新界定职务发明创造的专利申请权及专利权，平衡单位与发明人或设计人之间的利益。     

The process of formation of ocean crust

Ocean crust is the outermost layer of earth under the oceans. It is separated from the underlying mantle by a seismic transition zone called the Moho. A widely held view is that the Moho represents a petrologic change from basaltic-type rocks to a mantle composed mostly of olivine and pyroxene. According to this view, crust is formed by a steady segregation of basaltic melt, derived from partial melting of the mantle, into a crustal magma chamber wherein cooling and crystallization bring about steady-state accretion to the continuously spreading plates. There is sufficient disagreement between the predictions of this hypothesis and marine geophysical data to cause one to doubt the validity of this formation process. At least two other processes are more compatible with the geophysical data. In one, the crust is formed from the episodic injection of basaltic dikes from a mantle reservoir and the Moho is a primary petrologic boundary. In the other, the crust is treated as a mechanical boundary layer in which thermal contraction results in cracking; by comparison, in the mantle thermal contraction is accommodated by flow. The upper part of the crust is formed from episodic extrusion and intrusion of basaltic melt. The lower crust is formed by rapid hydrothermal alteration of mantle that may be continuously or episodically injected by viscous flow at temperatures below the melting temperature.     

Characterization of an extremely large, ligand-induced conformational change in plasminogen

Native human plasminogen has a radius of gyration of 39 angstroms. Upon occupation of a weak lysine binding site, the radius of gyration increases to 56 angstroms, an extremely large ligand-induced conformational change. There are no intermediate conformational states between the closed and open form. The conformational chang is not accompanied by a change in secondary structure, hence the closed conformation is formed by interaction between domains that is abolished upon conversion to the open form. This reversible change in conformation, in which the shape of the protein changes from that best described by a prolate ellipsoid to a flexible structure best described by a Debye random coil, is physiologically relevant because a weak lysine binding site regulates the activation of plasminogen.     

灰拟花尺蛾生物学特性的初步研究

灰拟花尺蛾是尺蛾类危害多种阔叶树木的食叶害虫,尤其是对天然林桦树林危害最为严重。此虫在青海湟源县1a发生一代,以卵在树皮裂缝中越冬,以蛹在土茧内越夏,幼虫出现于5月中旬,成虫出现于10月初。建议加强该虫的防治和检疫。     

First experiences with a negotiation decision support system contributing to milk price elaboration in Corsica

Milk pricing in Corsica is particularly affected by the secular traditions in sheep farming. The situation is now being exacerbated by the new constraints imposed by the international market conditions as well as by the large number of parties involved in the production and processing continuum. Establishing milk prices as far as quality is concerned presupposes: (a) a definition of standards, and (b) a convergence of different interests. Experiments were recently undertaken using a negotiation decision support system (NDSS) offered to farmers and industrial dairies by INRA researchers. This system seems to offer promising perspectives, both through the multiplication and storage of data and the serenity of the discussions that take place around a screen-relayed dialogue. It appears both desirable and possible for the experiment to be extended to cover other farm types. Nevertheless in its present form, this study should be seen as a first experiment in using the tool. The goal is neither to reach effective negotiation between the farmers and the dairies nor to establish, through this NDSS, a general forecasting model for all the responses to be expected during the development stages of this tool. The first aim is primarily educational, to induce and participate in the building of a ‘collective mind’ by better formalising the development phenomena.     

Clinical trial stirs legal battles

A lawsuit filed in federal court in Atlanta, Georgia, in February 1982 by two private ophthalmologists and seven prospective patients charges a group of academic physicians with attempting to monopolize radial keratotomy, a surgical procedure for correcting myopia, by labeling it experimental and urging restraint in its use. The parties have agreed to a settlement involving a payment of $250,000 by the defendants and a statement that the procedure is effective in qualified patients and should no longer be considered experimental. A second suit, brought by nine physicians in federal court in Chicago in June 1984, accuses the American Academy of Ophthamology of attempting to control the procedure. The broader issue at stake is how new surgical prdocedures should be evaluated before they are brought into widespread use. In the case of radial kerototomy, a large-scale clinical trial funded by the National Eye Institute is proceeding as planned despite the legal controversy.     

一种改进的双色SDS-PAGE凝胶和可视化上样电泳方法

SDS-PAGE电泳是蛋白质分析和研究中的重要高效手段．由于分离胶、浓缩胶与电泳缓冲液以及空气都是无色透明的物质,在胶的制作和点样过程中仅仅通过浓缩胶相与缓冲液水相或空气相对光的折射来准确判断点样孔的位置并进行点样操作,因而比较困难．该文介绍1种在浓缩胶中添加颜色染料,使浓缩胶显现颜色,以此可视化区分浓缩胶中点样孔（井）位置的方法,可以准确而高效完成点样操作,使传统的SDS-PAGE点样过程通过折光性来判断变为可视化准确判断,提高点样效率和电泳质量．