水平排列硅光二极管色传感器及其特性

简要介绍水平排列硅光二极管色传感器的制作工艺，该器件波长在５００ｎｍ到６５０ｎｍ范围内有一个单调的近于线性的光谱响应。入射光波长为６００ｎｍ时，入射光强度化五个数量级，测出的波长基本不变，器件波长分辨率、最低入射光强、长时间测量的波长漂移以及波长温漂系数等特性的测量结果表明：该类色传感器已达高性能实用要求。     

Little or no solar wind enters Venus' atmosphere at solar minimum

Venus has no significant internal magnetic field, which allows the solar wind to interact directly with its atmosphere. A field is induced in this interaction, which partially shields the atmosphere, but we have no knowledge of how effective that shield is at solar minimum. (Our current knowledge of the solar wind interaction with Venus is derived from measurements at solar maximum.) The bow shock is close to the planet, meaning that it is possible that some solar wind could be absorbed by the atmosphere and contribute to the evolution of the atmosphere. Here we report magnetic field measurements from the Venus Express spacecraft in the plasma environment surrounding Venus. The bow shock under low solar activity conditions seems to be in the position that would be expected from a complete deflection by a magnetized ionosphere. Therefore little solar wind enters the Venus ionosphere even at solar minimum.     

Cloning defined regions of the human genome by microdissection of banded chromosomes and enzymatic amplification

The molecular analysis of many genetic diseases requires the isolation of probes for defined human chromosome regions. Existing techniques such as the screening of chromosome-specific libraries, subtractive DNA cloning and chromosome jumping are either tedious or not generally applicable. Microdissection and microcloning has successfully been applied to various chromosome regions in Drosophila and mouse, but conventional microtechniques are too coarse and inefficient for analysis of the human genome. Because microdissection has previously been used on unbanded chromosomes only, cell lines in which the chromosome of interest could be identified without banding had to be used. At least one hundred chromosomes were needed for dissection and lambda vectors used to achieve maximum cloning efficiency. Recombinant phage clones are, however, more difficult to characterize than plasmid clones. Here we describe the dissection of the Langer-Giedion syndrome region on chromosome 8 from GTG-banded metaphase chromosomes (G-banding with trypsin-Giemsa) and the universal enzymatic amplification of the dissected DNA. Eighty per cent of clones from this library (total yield 20,000) identify single-copy DNA sequences. Fifty per cent of clones detect deletions in two patients with Langer-Giedion syndrome. Although the other clones have not yet been mapped, this result demonstrates that thousands of region-specific probes can be isolated within ten days.     

Inhibition of exocytosis by intracellularly applied antibodies against a chromaffin granule-binding protein

Exocytotic secretion requires the interaction and fusion of secretory vesicles with the plasma membrane. This process could be mediated by specific recognition molecules acting as intracellular, membrane-bound receptors and ligands. One possible component of such a recognition site on the plasma membrane is a protein of relative molecular mass (Mr) 51,000 (51K) that has been isolated from bovine adrenal chromaffin cells. This protein binds strongly to chromaffin granules, the secretory vesicles of these cells. To determine the function of this membrane-anchored chromaffin granule-binding protein in exocytosis, we tested the effect of intracellularly injected antibodies on secretion. Here we show, by two independent techniques in two different cell types, that antibodies against this protein inhibit exocytosis. In rat pheochromocytoma cell cultures, monospecific antibodies, applied by erythrocyte ghost fusion, impair the release of 3H-noradrenaline. The same antibodies, introduced into individual chromaffin cells through a patch pipette, block exocytosis, as revealed by the measurement of membrane capacitance. These results demonstrate the functional involvement in exocytosis of a plasma membrane protein with high affinity for secretory vesicles.     

加热U型管内压力降型脉动发生界限研究

从压力降型脉动发生的机理方面作了分析，用小扰动法计算了压力降型脉动发生的界限，同时用试验数据加以验证，还比较了３种不同布置的Ｕ型管的脉动界限。     

An intense stratospheric jet on Jupiter

The Earth's equatorial stratosphere shows oscillations in which the east-west winds reverse direction and the temperatures change cyclically with a period of about two years. This phenomenon, called the quasi-biennial oscillation, also affects the dynamics of the mid- and high-latitude stratosphere and weather in the lower atmosphere. Ground-based observations have suggested that similar temperature oscillations (with a 4-5-yr cycle) occur on Jupiter, but these data suffer from poor vertical resolution and Jupiter's stratospheric wind velocities have not yet been determined. Here we report maps of temperatures and winds with high spatial resolution, obtained from spacecraft measurements of infrared spectra of Jupiter's stratosphere. We find an intense, high-altitude equatorial jet with a speed of approximately 140 m s(-1), whose spatial structure resembles that of a quasi-quadrennial oscillation. Wave activity in the stratosphere also appears analogous to that occurring on Earth. A strong interaction between Jupiter and its plasma environment produces hot spots in its upper atmosphere and stratosphere near its poles, and the temperature maps define the penetration of the hot spots into the stratosphere.     

Bovine chromogranin A sequence and distribution of its messenger RNA in endocrine tissues

Chromogranin A is contained in storage vesicles of chromaffin cells of the adrenal medulla and released with catecholamines when the splanchnic nerve is stimulated. Chromogranin A is similar to secretory protein I (SP-I), a major secreted protein of the parathyroid. Chromogranin A/SP-I immunoreactivity is abundant in endocrine cells that secrete peptide hormones from storage vesicles. Chromogranins may act in neuroendocrine secretion by binding intravesicular calcium. Serum levels of chromogranin are raised in hypertension and endocrine neoplasia. We report here the isolation and sequencing of a cDNA encoding bovine chromogranin A, providing the first complete primary structure of a chromogranin protein. Chromogranin A is a highly acidic protein with an apparent relative molecular mass (Mr) of 75,000 on SDS-PAGE, but an actual Mr of 48,000. Adrenal medulla, brain, pituitary and parathyroid are all sites of synthesis of chromogranin A. The primary structure of chromogranin A, and the presence of chromogranin mRNA in the parathyroid, indicate that chromogranin A and SP-I are identical.     

Sequencing of Aspergillus nidulans and comparative analysis with A. fumigatus and A. oryzae

The aspergilli comprise a diverse group of filamentous fungi spanning over 200 million years of evolution. Here we report the genome sequence of the model organism Aspergillus nidulans, and a comparative study with Aspergillus fumigatus, a serious human pathogen, and Aspergillus oryzae, used in the production of sake, miso and soy sauce. Our analysis of genome structure provided a quantitative evaluation of forces driving long-term eukaryotic genome evolution. It also led to an experimentally validated model of mating-type locus evolution, suggesting the potential for sexual reproduction in A. fumigatus and A. oryzae. Our analysis of sequence conservation revealed over 5,000 non-coding regions actively conserved across all three species. Within these regions, we identified potential functional elements including a previously uncharacterized TPP riboswitch and motifs suggesting regulation in filamentous fungi by Puf family genes. We further obtained comparative and experimental evidence indicating widespread translational regulation by upstream open reading frames. These results enhance our understanding of these widely studied fungi as well as provide new insight into eukaryotic genome evolution and gene regulation.     

Synthesis of Casein Graft Acrylonitrile and Side Chain Distribution of Graft Copolymer

Graft copolymerization of casein with acrylonitrile wascarried out using potassium persulfate as an initiator.First,solubility of casein in several solvents was studiedin order to choose a solvent for graft reaction.Percentgrafting and grafting efficiency under various concentra-tions of initiator and monomer,and various times wereevaluated.A method to separate side chain from graftcopolymer was explored.Side chain length and its distri-bution were investigated.FTIR spectra for side chain,casein,and grafted copolymer were taken to establishthe occurrence of grafting.The thermal property ofgraft copolymer was measured and confirmed that the T_pof the copolymer was improved appreciably.