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1.
Emma Bricchi Marco Fornaciari Claudia Giannoni Francesca Greco Daniela Fascini Giuseppe Frenguelli Gianfranco Mincigrucci Bruno Romano 《Aerobiologia》1992,8(3):401-406
Summary Gramineae pollination from a pollen monitoring station located in the eastern suburb of Perugia and meteorological correlations are reported. The data refers to the year 1989. Grass pollen peak pollination was from May to July; in this period the influence of relative humidity and of temperature on pollen concentration was very high. Phenological observations, to identify the time of maximum stamen extension in the most common genera in the area, are also reported. During the period of investigation the counts of pollen grains over four-hour periods showed a regular diurnal rhythm with peaks of concentration in the four-hour period 16.00–20.00. Aerosporological data and meteorological data related to four-hour periods were correlated following different criteria. 相似文献
2.
3.
Yiwen Sun Zexuan Zhu Siping Chen Jega Balakrishnan Derek Abbott Anil T. Ahuja Emma Pickwell-MacPherson 《PloS one》2012,7(11)
The GP2 peptide is derived from the Human Epidermal growth factor Receptor 2 (HER2/nue), a marker protein for breast cancer present in saliva. In this paper we study the temperature dependent behavior of hydrated GP2 at terahertz frequencies and find that the peptide undergoes a dynamic transition between 200 and 220 K. By fitting suitable molecular models to the frequency response we determine the molecular processes involved above and below the transition temperature (T
D). In particular, we show that below T
D the dynamic transition is dominated by a simple harmonic vibration with a slow and temperature dependent relaxation time constant and that above T
D, the dynamic behavior is governed by two oscillators, one of which has a fast and temperature independent relaxation time constant and the other of which is a heavily damped oscillator with a slow and temperature dependent time constant. Furthermore a red shifting of the characteristic frequency of the damped oscillator was observed, confirming the presence of a non-harmonic vibration potential. Our measurements and modeling of GP2 highlight the unique capabilities of THz spectroscopy for protein characterization. 相似文献
4.
Isolation and characterization of an abundant and novel 22-kDa protein (SM22) from chicken gizzard smooth muscle 总被引:4,自引:0,他引:4
J P Lees-Miller D H Heeley L B Smillie C M Kay 《The Journal of biological chemistry》1987,262(7):2988-2993
Chicken gizzard smooth muscle contains a highly abundant protein (SM22) with an apparent Mr on sodium dodecyl sulfate-polyacrylamide electrophoretic gels of 23,000. The ratio of actin:SM22:tropomyosin in this tissue is estimated to be 6.5(+/- 0.8):2.0(+/- 0.2):1.0. At least three isoelectric isoforms are present in ratios of alpha:beta:gamma of 14:5:1 with alpha the most basic and gamma the most acidic. A method for the purification of SM22 and partial separation of its isoforms is described. Amino acid analyses of purified alpha and beta demonstrate the presence of 1 and 2 half-cystines, respectively, and a lower content of basic amino acids in beta. A value of 22,000 for the Mr of alpha estimated by sedimentation equilibrium indicated its presence as a monomer at physiological ionic strengths. Estimates of the translational frictional coefficient (f/fmin) of alpha calculated from its Stokes radius (25.5 A) and Mr were consistent with its existence as a moderately asymmetric globular protein. Calculations based on its far-ultraviolet CD spectrum provided values of 37% alpha-helix, 31% beta-sheet, 5% beta-turn, and 27% random coil. SM22 was shown not to share functional properties with several proteins of similar Mr and isoelectric point such as myokinase, brain 23-kDa protein, and troponin I. We conclude that it is a novel protein not previously isolated or characterized from any tissue. 相似文献
5.
G.D.W. Curtis R.G. Mitchell Andrea F. King Emma J. Griffin 《Letters in applied microbiology》1989,8(3):95-98
A new medium has been developed for the isolation of Listeria monocytogenes from clinical specimens with a mixed flora. Almost complete inhibition of unwanted organisms was achieved and recognition of colonies of Listeria spp. was usually possible after 24 h using the aesculin-ferric ammonium citrate indicator system. Compared to McBride agar the new medium was more inhibitory to representative contaminating species in pure culture and more successful in isolating small numbers of L. monocytogenes from artificially seeded clinical specimens. 相似文献
6.
Giuseppe Frenguelli Emma Bricchi Bruno Romano Gianfranco Mincigrucci Francesco Ferranti Evasio Antognozzi 《Aerobiologia》1992,8(3):415-418
Summary 7 years of airborne pollen monitoring in Perugia (central Italy) were used to determine the temperature requirements to break dormancy and to resume growth and bloom ofCorylus avellana L.,Corylus needs 1000 chill-units to complete its dormancy and this value, in the Perugian area, is met by the end of December or the first days of January. MoreoverCorylus trees require 220 growth degree hours before they are able to flower. If air temperature is high, this value can be achieved in only 10 days, but if the temperature remains too low, the heat accumulation can require up to 35 days. With these parameters it is possible to build a model to predict the date of the beginning ofCorylus avellana pollen season. 相似文献
7.
8.
Continuous pollen monitoring of an urban network consisting of three stations has been undertaken for a period of 2 years
in Perugia, central Italy. The aim has been to establish whether the Perugia pollen trap, active since 1983, is still representative
of the area following recent urbanisation. Quantitative differences were found between the stations, reflecting different
vegetational areas, but only slight differences were detected in relation to the timing of the principal period of pollination.
Therefore, although individual pollen traps are necessary to characterize fully the different areas, one trap is sufficient
to determine the key allergenic thresholds in the studied area. 相似文献
9.
Continuous pollen monitoring of an urban network consisting of three stations has been undertaken for a period of 2 years in Perugia, central Italy. The aim has been to establish whether the Perugia pollen trap, active since 1983, is still representative of the area following recent urbanisation. Quantitative differences were found between the stations, reflecting different vegetational areas, but only slight differences were detected in relation to the timing of the principal period of pollination. Therefore, although individual pollen traps are necessary to characterize fully the different areas, one trap is sufficient to determine the key allergenic thresholds in the studied area. 相似文献
10.
In comparison to wild type Arabidopsis thaliana, the auxin resistant mutants axr1 and axr2 exhibit reduced inhibition of root elongation in response to auxins. Several auxin-regulated physiological processes are also altered in the mutant plants. When wild-type, axr1 and axr2 seedlings were grown in darkness on media containing indoleacetic acid (IAA), promotion of root growth was observed at low concentrations of IAA (10?11 to 10?7M) in 5-day-old axr2 seedlings, but not in axr1 or wild-type seedlings. In axr1 there was little or no measurable root growth response over the same concentration range. In wild type, root growth was inhibited at concentrations greater than 10?10M and no detectable root growth response was observed at lower concentrations. In addition, production of lateral roots in response to IAA increased in axr2 seedlings and decreased in axr1 seedlings relative to wild type. Promotion of root elongation and initiation of lateral roots in axr2 seedlings in response to auxin indicate that axr2 seedlings are able to perceive and respond to IAA. 相似文献