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物理教师 1986年第1期 19-20页

作者：王广礼四川宁南县一中

如下图所示的实验装置可以用来验证向心力公式f=mv~2/R。使摆长为R、质量为m的摆球偏离平衡位置升高h后,让其自由摆动。当摆球到达平衡位置O点的瞬间,它受到竖直向上的拉力T和竖直向下的重力mg的作用,设摆球摆到O点时的速率为v,根据牛... 详细信息

如下图所示的实验装置可以用来验证向心力公式f=mv~2/R。使摆长为R、质量为m的摆球偏离平衡位置升高h后,让其自由摆动。当摆球到达平衡位置O点的瞬间,它受到竖直向上的拉力T和竖直向下的重力mg的作用,设摆球摆到O点时的速率为v,根据牛顿第二定律有

关键词： f=m v~2/R 平衡位置向心力公式 f

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几个力学定律的内在f=-f′ f=ma联系及其使用条件

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物理教学 1986年第7期 3-4页

作者：胡运惠胡建平

在力学中,几个常用的定律和定理是:牛顿第二定律、动量原理、动量守恒定律、动能定理、功能原理和机械能守恒定律等。它们反映了物体运动所遵循的基本规律,是解决力学问题的钥匙和原则。其中最重要的或者最基本的是牛顿定律,其余各条定... 详细信息

在力学中,几个常用的定律和定理是:牛顿第二定律、动量原理、动量守恒定律、动能定理、功能原理和机械能守恒定律等。它们反映了物体运动所遵循的基本规律,是解决力学问题的钥匙和原则。其中最重要的或者最基本的是牛顿定律,其余各条定律和定理都是在它的基础上利用运动学的公式,根据一定的条件而推导出来的。其内在关系可用下例阐明。今有一斜面(如图1所示),其底边和斜面的夹角为θ。某一质量为m的物体,在恒力f

关键词：动能定理功能原理动量守恒定律动量原理力学定律重力势能合外力 f

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VARIANCE ANALYSIS BY USE Of A LOW-COST DESK TOP CALCULATOR

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COMPUTERS IN BIOLOGY AND MEDICINE 1986年第4期16卷 311-317页

作者： REVALDERIA, JG VILLAfRUELA, JJ SABATER, J LAMAS, S ORTUNO, J Department of Nephrology Centro Ramon y Cajal Carretera de Colmenar Km. 9100 28034 Madrid Spain

A simple program for an HP-97 desk top calculator, which can be adapted to an HP-67, is presented. This program detects the presence of an added component of variance in any series classified with a unique criterion. Each series can be formed by any number of data. The program supplies additional information about this component. A brief theoretical description and a practical example are also included.

关键词： Variance analysis Unique criterion Added components f -test Student t -test Method HP-97 program

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STABILITY Of STRUCTURES Of THE EPSILON SUBUNIT AND TERMINATOR Of THERMOPHILIC ATPASE

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BIOCHIMICA ET BIOPHYSICA ACTA 1986年第3期867卷 97-106页

作者： SAISHU, T NOJIMA, H KAGAWA, Y JICHI MED SCH DEPT BIOCHEM Minami Kawachi TOCHIGI 32904 JAPAN JICHI MED SCH DEPT PHARMACOL Minami Kawachi TOCHIGI 32904 JAPAN JICHI MED SCH DEPT ANESTHET Minami Kawachi TOCHIGI 32904 JAPAN

f1-type ATPase is the central enzyme for ATP synthesis in most organisms. Because of the extreme reconstitutability of thermophilic ATPase (Tf1) and diversity of the minor subunits of f1 type ATPase, an operon coding for Tf1 was isolated from DNA of thermophilic bacterium PS3, and its terminal region containing the .epsilon. subunit (***.) and terminator was sequenced. The primary structure of the .epsilon. subunit (Mr = 14333) was deduced from the nucleotide sequence (396 base-pairs) and amino-acid sequence of its amino terminus. The conclusions drawn from the results are as follows. (1) Homologies: Tf1 e shows only 6% homology with the .epsilon. subunits of eight species reported, but 50% homology with Escherichia coli .epsilon. and 41% with chloroplast. The residues having a tendency to form reverse turns (Gly, Pro and Tyr) and His are relatively well conserved. Unlike some ***. types ***. has no ATPase inhibitor activity and is not homologous with ATPase inhibitor. ***. is essential to connect f1 to f0, like the b subunit, and is weakly homologous with the b subunit of fof1. (2) The cause of 3 .beta.:1 .epsilon. subunit stoichiometry: The ribosome binding sequence of ***. is TAGGN7, which is incomplete compared with that of ***.. The codon usage for ***. is similar to that for ***.. (3) The cause of stability of ***. and its gene: There are 18 ionic groups at the putative reverse turns and the N- and C-termini of ***., but only 10 ionic groups in the corresponding sites of E. coli .epsilon. subunit. These ionic groups enhance the external polarity of ***. and may intensify subunit-subunit interaction. There is a terminator at the 3'' end of the ***. gene, which is stabilized by a long (13 base-pairs) stem.

关键词： ATPase Nucleotide sequence Amino-acid sequence Subunit composition (Thermophilic bacterium P53) fof 1 proton translocating ATPase or ATP synthase Tfof 1 thermophilic fof 1 f 1 catalytic portion of fof 1 fo proton channel portion of fof 1 Tf 1 thermophilic f 1 Tf 1 β the β subunit of Tf 1 , Tf 1 ε, the ε subunit of Tf 1 Ef 1 f 1 of E. coli

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RENORMALIZATION Of SPECTRAL WIDTHS BY SCREENING INTERACTIONS

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JOURNAL Of PHYSICS AND CHEMISTRY Of SOLIDS 1986年第5期47卷 473-476页

作者： RISEBOROUGH, PS Department of Physics Polytechnic Institute of New York 333 Jay Street Brooklyn NY 11201 U.S.A.

In some of the rare earth compounds the width of the 4 f electron spectral density is dominated by processes which involve the transfer of electrons between the f shell and the conduction band. We examine the effects that screening of the 4 f shell's charge density by the conduction electrons have on these hybridization widths. The screening interaction is treated by low-order perturbation theory. We conclude that the screening of the excess charge on the 4 f ion may result in a reduction of this hybridization width, in a manner analagous to the enhancement of the effective mass of the small polaron.

关键词： rare earths 4 f spectral density hybridization widths screening interaction

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fORMYLMETHIONYL TRANSfER RNA-BINDING TO 30-S RIBOSOMES PROGRAMMED WITH HOMOPOLYNUCLEOTIDES AND THE EffECT Of TRANSLATIONAL INITIATION fACTOR-III

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BIOCHIMICA ET BIOPHYSICA ACTA 1986年第2-3期866卷 144-153页

作者： BERKHOUT, B VANDERLAKEN, CJ VANKNIPPENBERG, PH STATE UNIV LEIDEN DEPT BIOCHEM WASSENAARSEWEG 64 2333 AL LEIDEN NETHERLANDS

Binding of the polynucleotides poly(U), poly(X) and poly(dT) to 30 S ribosomes of Escherichia coli triggers If2-dependent binding of initiator-tRNA (fMet-tRNA) to these particles. Poly(A)and poly(C) are inactive. A minimum chain-length of approximately 100 residues in poly(U) is required for full activity in fMet-tRNA binding although much shorter polymers bind tightly to 30 S particles and do stimulate the binding of acPhe-tRNA. The stimulation of fMet-tRNA binding to 30 S ribosomes is strongly reduced under conditions where the polynucleotides adopt secondary structure. Complexes containing fMet-tRNA and the non-cognate codon UUU or XXX are destabilized by If3, whereas the formation of such a complex containing an AUG codon is slightly enhanced by the factor. Consistent with previous observations, it was found that all model initiation complexes containing acPhe-tRNA are strongly destabilized by If3, even when the cognate codon (UUU) is present. Our results suggest that If3 counteracts ''unnatural'' initiation events in vitro and suggest a regulatory role for this factor in vivo.

关键词： Protein synthesis Initiation factor If3 Initiation codon Translation Polynucleotide acPhe-tRNA N -acetylphenylalanyl-transfer RNA Phe fMet-tRNA N -formylmethionyl-transfer RNA Met f (initiator-tRNA) If initiation factor poly(A) poly(adenylic acid) poly(A, U, G) random copolymer of adenylic, uridylic and guanylic acid (ratio 1:1:1) poly(C) poly(cytidylic acid) poly(dT) poly(deoxythymidylic acid) poly(U) poly(uridylic acid) poly(X) poly(xanthidylic acid) (U) n polymer of n residues uridylic acid U − n poly(U) with an average chain length of n nucleotides

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EffECTS Of THE MODIfICATION Of TRANSfER BUffER COMPOSITION AND THE RENATURATION Of PROTEINS IN GELS ON THE RECOGNITION Of PROTEINS ON WESTERN BLOTS BY MONOCLONAL-ANTIBODIES

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ANALYTICAL BIOCHEMISTRY 1986年第1期157卷 144-153页

作者： DUNN, SD Department of Biochemistry University of Western Ontario London Ont. N6A 5C1 Canada

Two modifications to Western blots which enhance immunochemical recognition have been developed. The first is transfer in carbonate buffer at pH 9.9, rather than the more commonly used Tris-glycine buffer at pH 8.3. This alteration improved the recognition of four of the five subunits of Escherichia coli f1-ATPase by monoclonal antibodies, the smaller subunits showing the greatest effects. Recognition of dinitrophenyl groups attached to the subunits by polyclonal antibodies was improved by the carbonate buffer only for the smallest ATPase subunit, .epsilon.. The second modification was incubation of the gel in mild buffers, designed to promote the renaturation of proteins, before the elelectrophoretic transfer step. The most effective buffer was 20% glycerol in 50 mM Tris-HCl, pH 7.4. Improvements in the signal obtained with monoclonal antibodies to all the subunits of ATPase were obtained by this procedure. As the subunits vary markedly in size, isoelectric point, and other properties, this method should be useful for most proteins. The fate of the 15,000-Da .epsilon. subunit, labeled with 125I, was followed through a blotting experiment. As long as no sodium dodecyl sulfate was added to the transfer buffer, .epsilon. was bound to nitrocellulose efficiently in either Tris-glycine or carbonate buffer. However, the .epsilon. was retained much more strongly during the subsequent incubation steps if the transfer was done in the carbonate buffer. The binding of .epsilon. to the nitrocellulose was even more stable when the gel had been treated with the buffered glycerol solution before transfer. These results indicate that the conditions under which .epsilon. subunit first encounters the nitrocellulose markedly affect the stability of binding during subsequent steps. The f1-ATPase was partially fragmented by treatment with proteases and then run on a gel and either transferred immediately in Tris-glycine buffer or else treated with the buffered glycerol solution and tran

关键词： monoclonal antibodies immunochemical methods Western blots blotting to nitrocellulose f 1 -ATPase

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LOCALIZATION AND IDENTIfICATION Of NEURONS WITH CHOLECYSTOKININ AND GASTRIN-LIKE IMMUNOREACTIVITY IN WHOLEMOUNTS Of APLYSIA-GANGLIA

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NEUROSCIENCE 1986年第4期18卷 957-974页

作者： ONO, JK Division of Neurosciences Beckman Research Institute of the City of Hope 1450 E. Duarte Rd. Duarte CA 91010 U.S.A.

Immunohistochemical procedures were applied to wholemounts of the central nervous system and posterior intestine of the mollusc, Aplysia californica, to facilitate localization of cells that were immunoreactive to several antisera recognizing various epitopes of the peptides cholecystokinin and gastrin. Only antisera that recognized the carboxyl terminal sequence common to cholecystokinin and gastrin reacted with the Aplysia tissues tested. Intracellular electrophysiological studies of identified postsynaptic targets of immunoreactive neurons in the cerebral ganglia indicated that mammalian forms of gastrin 1-17, several cholecystokinin fragments, and the related peptide, amphibian caerulein, did not mimick the synaptic responses mediated by the immunoreactive presynaptic neurons. Combinations of electrophysiological, immunohistochemical, and biochemical studies of several neurons in the buccal ganglia indicated that neurons B7 and B13 were immunoreactive to antisera against cholecystokinin and gastrin and that neuron B13 also contained a concentration of the neurotransmitter acetylcholine as high as in the identified cholinergic buccal neurons, B4 and B5. Several differences in the immunoreactivity of the various antisera were observed. Only one of the antisera was effective in staining neurons in the abdominal ganglia and another antiserum stained subsets of neurons that were immunoreactive to most of the other antisera recognizing the carboxyl terminus common to cholecystokinin and gastrin. The giant serotoninergic metacerebral neurons in Aplysia were not immunoreactive to the cholecystokinin/gastrin antisera even though it has been reported that the homologous neurons in a pulmonate mollusc contain cholecystokinin-like immunoreactivity. These studies demonstrated that there are many neurons with cholecystokinin/gastrin-like immunoreactivity in the Aplysia central and peripheral nervous system and suggested that the peptide may differ from vertebrate forms of cho

关键词： 5-HT 5-hydroxytryptamine or serotonin ACh acetylcholine aCCK anti-cholecystokinin aGTN anti-gastrin ARC accessory radular muscle BSA bovine serum albumin CCK cholecystokinin peptide fragments are numbered from the carboxyl terminus toward the amino terminus, e.g. CCK 1-8, CCK octapeptide CCK/G-li cholecystokinin/gastrinlike E f PSP fast excitatory postsynaptic potential E f I s PSP fast excitatory, slow inhibitory postsynaptic potential I f PSP fast inhibitory postsynaptic potential I f E s PSP fast inhibitory, slow excitatory postsynaptic potential IMN Immunonuclear PAP peroxidaseantiperoxidase PBS phosphate-buffered saline PSP postsynaptic potential

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DENDRITIC CHANGES IN THE BASAL NUCLEUS Of MEYNERT AND IN THE DIAGONAL BAND NUCLEUS IN ALZHEIMERS-DISEASE - A QUANTITATIVE GOLGI INVESTIGATION

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NEUROSCIENCE 1986年第4期19卷 1265-1278页

作者： ARENDT, T ZVEGINTSEVA, HG LEONTOVICH, TA KARL MARX UNIV LEIPZIG PAUL FLECHSIG INST BRAIN RES DEPT NEUROCHEM KARL MARX STADTER STR 50 DDR-7039 LEIPZIG GER DEM REP ACAD MED SCI USSR INST BRAIN RES NEURONAL STRUCT LAB MOSCOW 109801 USSR

Golgi-impregnated reticular neurons and multipolar giant neurons, the two main classes of neurons in the basal nucleus of Meynert and in the diagonal band nucleus, were investigated morphometrically in five cases of Alzheimer''s disease, and compared to controls. Both degenerative as well as regenerative neuronal changes were observed in cases of Alzheimer''s disease. Degenerative changes such as irregular swellings and the fragmentation of dendrites are most pronounced on reticular neurons but can also be detected to a lesser extent on multipolar giant neurons. Regenerative changes are restricted to reticular neurons. They are characterized by the appearance of perisomatic filopodia, by an increase in the size of cell soma, by an increase in the degree of dendritic arborization and spatial extension of the dendritic tree. These regenerative changes are probably signs of a compensatory mechanism which might be induced by degeneration in this area.

关键词： AD Alzheimer's disease A c dendritic ramification of a neuron A d mean ramification of a single dendrite Ch 2 vertical limb of the diagonal band nucleus Ch 4am anterior-medial part of the NbM Ch 4al anterior-lateral part of the NbM Ch 4i intermediate part of the NbM in the substantia innominata Cl cross-sectional cell area DB diagonal band nucleus f tormfactor L d total length of dendrites per neuron L ds mean length of dendritic segments of each order NbM nucleus hasalis of Meynert N d density of dendrites R largest radius of dendritic area S n total number of dendritic segments per neuron S 1 to S 7 number of dendritic segments of each order V da volume of the dendritic area

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LACK Of ISOTYPE EXCLUSION AND EXPRESSION Of ABERRANT LAMBDA-LIGHT CHAIN ON SECRETED MOPC-315 MYELOMA PROTEINS

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MOLECULAR IMMUNOLOGY 1986年第1期23卷 79-85页

作者： JU, ST PINTO, D DORf, ME Department of Pathology Harvard Medical School 25 Shattuck Street Boston MA 02115 U.S.A.Received 25 June 1985 Accepted 19 July 1985 Available online 13 November 2002

The presence of aberrant .lambda.1 light (L) chain fragment (.lambda.1f) on the secreted myeloma protein of MOPC-315 has been demonstrated by serological and immunochemical methods. We developed a highly sensitive radiommunoassay that utilizes exquisitely specific xenogeneic anti-.lambda.1 antibodies to detect the minute amounts of .lambda.1f on .lambda.2-bearing MOPC-315 myeloma proteins. In addition, structural evidence that .lambda.f is present on MOPC-315 myeloma protein was demonstrated by subjecting 125I-labelled MOPC-315 myeloma protein to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under reducing conditions followed by autoradiography. The relative amounts of .lambda.1f and .lambda.2-chain on MOPC-315 myeloma were measured by two independent methods. The molar ratio of .lambda.1f to .lambda.2 was calculated to be 1:68 by radioimmunoassay and 1:80 by analytical SDS-PAGE. This represents the first demonstration that an aberrant L-chain fragment combines with a heavy chain and is secreted in association with antigen-binding myeloma proteins. The implications of these results on L-chain isotype exclusion are discussed.

关键词： BSA bovine serum albumin DNP dinitrophenyl H-chain heavy chain K kappa light chain L-chain light chain λ 1 f λ 1 -fragment of mol. wt 18,000 NP (4-hydroxy-3-nitrophenyl) acetyl PBS phosphate-buffered saline SDS-PAGE sodium dodecyl sulfate-polyacrylamide gel electrophoresis

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