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1.
Morphometry and composition of aragonite and vaterite otoliths of deformed laboratory reared juvenile herring from two populations 总被引:2,自引:0,他引:2
Vaterite otoliths were sampled from two reared populations (Celtic and Clyde Seas) of juvenile herring Clupea harengus. The crystallography, elemental composition and morphometry were analysed and compared with those of normal aragonite otoliths. The incidence of vaterite otoliths in the juveniles sampled (n = 601) ranged from 7·8% in the Clyde population to 13·9% in the Celtic Sea population, and was 5·5% in the small sample (n = 36) of wild adults examined. In all but one case fish had only one vaterite otolith; the corresponding otolith of the pair was completely aragonite. Although the majority of the juveniles sampled showed craniofacial deformities, there was no link between the skull or jaw malformation and the incidence of vaterite otoliths. All vaterite otoliths had an aragonite inner area, and vaterite deposition began sometime after the age of 90 days. The vaterite otoliths were larger and lighter than their corresponding aragonite partners, and were less dense as a consequence of the vaterite crystal structure. The vaterite areas of the otoliths were depleted in Sr, Na and K. Concentrations of Mn were higher in the vaterite areas. The transition between the aragonite inner areas and the vaterite areas was sharply delineated. Within a small spatial scale (20 μm3) in the vaterite areas, however, there was co‐precipitation of both vaterite and aragonite. The composition of the aragonite cores in the vaterite otoliths was the same as in the cores of the normal aragonite otoliths indicating that the composition of the aragonite cores did not seed the shift to vaterite. Vaterite is less dense than aragonite, yet the concentrations of Ca analysed with wavelength‐dispersive spectrometry (WDS) were the same between the two polymorphs, indicating that Ca concentrations measured with WDS are not a good indicator of hypermineralized zones with high mineral density. The asymmetry in density and size of the otoliths may cause disruptions of hearing and pressure sensitivity for individual fish with one vaterite otolith, however, the presence of vaterite otoliths did not seem to affect the growth of these laboratory reared juvenile herring. 相似文献
2.
G. -J. A. Vidugiris A. V. Gudavičius V. J. Razumas J. J. Kulys 《European biophysics journal : EBJ》1989,17(1):19-23
Surface enhanced Raman scattering (SERS) of some enzymes (alkaline phosphatase, horseradish peroxidase and lactoperoxidase) and some amino acids (tryptophan, tyrosine and phenylalanine) on silver electrodes has been studied. The spectral band intensities of certain amino acids and amino acid residues were determined by their orientation on the surface and depended on the electrode potential (E).Abbreviations SERS
surface enhanced Raman scattering
- Trp
tryptophan
- Tyr
tyrosine
- Phe
phenylalanine
- E
electrode potential
- ORC
oxidation-reduction cycle 相似文献
3.
Perturbations induced by a toxic lectin (ricin) on lipid organisation of model membranes prepared with DPPC and DPPC-cerebrosides mixtures have been analysed by Raman and infrared spectroscopy, two powerful and non-invasive methods. Our approach involves the observation of changes in the vibrational spectra of liquid multilayers in the PO
2
-
, C=0 and CH2 spectral regions for two lipid: ricin molar ratios (225:1, 75:1).The interfacial and polar regions of the multilayers, analysed by FTIR, appear to be perturbed by the protein. With both kinds of membranes, ricin mainly perturbs the C=0 ester groups of the sn-2 acylchain of DPPC. In the PO
2
-
stretching region, the frequency shifts are correlated with changes in polar group hydration.In the hydrophobic core of the multilayer membrane studied by Raman spectroscopy, the interaction of ricin is associated with changes in lipid packing. These perturbations depend upon the lipid composition of the membrane. With DPPC membranes, an affect is detected at temperatures lower than T
m
.It corresponds to a decrease of the lipid ordering. With DPPC-cer membranes, the protein increases the acylchain packing order regardless of the temperature of the experiments (10°C<T<75°C). No perturbation of T
m
is observed after addition of ricin to either DPPC or DPPC-cer membranes.The different perturbations detected by Raman and FTIR suggest that ricin mainly interacts with the interfacial domains of the membranes. 相似文献
4.
In situ high-temperature, high-pressure Raman experiments on 3 mM (pH 5) aqueous solutions of hen egg-white (HEW) lysozyme show a decrease in the relative height of the 505 cm–1 band associated with S-S stretching vibrations at 72°C (1 bar). The peak height changes are accompanied by significant band broadening, and the integrated band intensity does not change within experimental error. The effect of increased pressure at 72°C was to hinder broadening of the 505 cm–1 band. HEW lysozyme (2.4 mM,pH 5) was also heated at 76°C, 80°C, and 95°C for different periods of time, and aliquots were quenched to room temperature for Raman and enzymatic activity measurements. After 9 hr at 76°C, the protein exhibits enzyme activity less than 50% of the initial value, and approximately 50% reduction in activity is achieved after 3 hr at 80°C or 1 hr at 95°C. The Raman results suggest that different irreversibly denatured conformations are attained during prolonged exposures at these different temperatures. It is apparent from these studies that the S-S stretch intensity is decreased irreversibly. 相似文献
5.
Selective analysis of antitumor drug interaction with living cancer cells as probed by surface-enhanced Raman spectroscopy 总被引:1,自引:0,他引:1
A new technique for the selective measurement of small amounts of antitumor drugs in the nucleus and cytoplasm of a living cancer cell, based on surface-enhanced Raman spectroscopy (SERS), is proposed. The ability to detect SERS signals from very dilute (up to 10–10
M) solutions of doxorubicin or adriamycin (DOX), and 4O-tetrahydropyranyl-adriamycin (THP-ADM), as well as from their complexes with targets in vitro and in vivo, has been demonstrated. SERS spectra were obtained from a population as well as from single living erythroleukaemic K562 cells treated with DOX. The results of the measurements on the population of cells containing DOX in nuclei or in the cytoplasm are well correlated with the microscopic SERS measurements on the single cells treated with DOX, obtained by selectively recording signals from the living cell nucleus or from the cytoplasm. Possibilities for the application of this new technique in different aspects of cancer research are discussed.Abbreviations DNA
deoxyribonucleic acid
- DOX
doxorubicin
- SERS
surface-enhanced Raman spectroscopy
- THP-ADM
4O-tetrahydropyranyl adriamycin
- PBS
phosphate buffered saline
Offprint requests to: M. Manfait 相似文献
6.
S.Y.K. Wen D. Hess J.W. Kauffman J.M. Collins L.J. Lis 《Chemistry and physics of lipids》1983,32(2):165-173
Raman spectroscopy and X-ray diffraction are used to study the effect of heat and Ca2+ on dimyristoylphosphatidylethanolamine dispersions. Unlike phosphatidylcholine dispersions, dimyristoylphosphatidylethanolamine bilayers (at pH 8) require heating above Tm in order for hydration to occur and apparently bind Ca2+ at very low levels. These results are related to models for membrane fusion. 相似文献
7.
Resonance Raman experiments were performed on different green bacteria. With blue excitation, i.e. under Soret resonance or preresonance conditions, resonance Raman contributions were essentially arising from the chlorosome pigments. By comparing these spectra and those of isolated chlorosomes, it is possible to evaluate how the latter retain their native structure during the isolation procedures. The structure of bacteriochlorophyll oligomers in chlorosomes was interspecifically compared, in bacteriochlorophyllc- and bacteriochlorophylle- synthesising bacteria. It appears that interactions assumed by the 9-keto carbonyl group are identical inChlorobium limicola, Chlorobium tepidum, andChlorobium phaeobacteroides. In the latter strain, the 3-formyl carbonyl group of bacteriochlorophylle is kept free from intermolecular interactions. By contrast, resonance Raman spectra unambiguously indicate that the structure of bacteriochlorophyll oligomers is slightly different in chlorosomes fromChloroflexus auranticus, either isolated or in the whole bacteria. 相似文献
8.
U. Bässler U. Nothof 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1994,175(1):23-33
In the artificially closed femur-tibia control system of stick insects oscillations were induced in 3 different ways: Increasing the phase-shift by introducing an electronic delay, afference sign reversal and coupling the tibia to an inert mass. In all 3 cases the oscillations stopped after some time. The gain of the open-loop system was significantly smaller after the oscillations. Afference sign reversal by surgically crossing of the receptor apodeme of the femoral chordotonal organ for 25–85 days does not lead to altered characteristics of the control loop. When sinusoidal passive movements are forced upon the intact femur-tibia joint the forces resisting these movements do not decrease with time. In contrast to direct stimulation of the femoral chordotonal organ, these passive movements also influence the contralateral leg. The experiments show that the gain-control system of the femur-tibia control loop of stick insects consists of at least two components: A sensitization system (with inputs from many kinds of stimuli indicating some kind of disturbance) increases the gain of all reflex loops. A specific habituation-like system decreases the gain with repetitive stimulation only of one control system.Abbreviations fCO
femoral chordotonal organ
- SETi
slow extensor tibiae motor neuron 相似文献
9.
用共振拉曼和紫外-可见吸收光谱研究了水溶金属卟啉4-N-乙酸乙酯基-吡啶基铜卟啉和镍卟啉[简称Cu(NEAE)和Ni(NEAE)]及4-N-乙腈基-吡啶基铜卟啉[简称Cu(NACN)]与小牛胸腺DNA的相互作用。分析表明Cu(NEAE)、Ni(NEAE)和Cu(NACN)分别以外部键联、部分插入和沟槽方式与DNA作用;卟啉插入DNA时吡啶基团向卟啉环平面转动但不可能转成与之共面;而以非插入方式作用时吡啶基团会向垂直于或者平行于卟啉环平面转动。吡啶取代基的大小和空间位阻是影响相互作用方式的关键因素之一。 相似文献
10.
别藻蓝蛋白藻蓝胆素发色团分子构象研究 总被引:1,自引:0,他引:1
主要研究了蓝绿藻污棕席藻(Phormidium luridum)别藻蓝蛋白在不同 pH值条件下的吸收光谱和共振拉曼光谱.发现低聚化的结果导致了三聚体别藻蓝蛋白 650nm 特征吸收峰的消失和一些共振拉曼带强度和位置的移动.结果表明在低 pH 值作用下的低聚化的别藻蓝蛋白中藻蓝胆素发色团分子的构象和自由胆素分子类似,比三聚体的别藻蓝蛋白的发色团分子更趋于卷曲,折叠的构象态.而三聚体的别藻蓝蛋白,主要的拉曼带 1645cm-1是其发色团分子构象处于更线性延展的标志,其光谱行为和吸收光谱 Avis/Auv所表征的发色团分子构象的结果相一致. 相似文献