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1.
1.  The activities of glycolytic enzymes and of related enzymes of anaerobic carbohydrate metabolism were determined inTubifex. The complete line of glycolytic enzymes was detected (Table 1). Only very little lactate dehydrogenase activity could be detected, while high activities of enzymes essential for the production of alanine and succinate are present.
2.  Under anaerobic conditions, lactate, alanine, succinate and volatile fatty acids are formed from14C-labeled glucose (Tables 2 and 3).
3.  Glycogen degradation was measured under anaerobic conditions (Fig. 1).
4.  During anaerobiosis a significant increase of alanine, succinate, propionate and acetate was found. However, the concentration of lactate increased only slightly. After an initial increase within the first 24 h of anaerobiosis, the concentration of alanine remained constant. Succinate, on the other hand, accumulated continuously during 48 h of anaerobiosis, reaching concentrations of 150 mol/g dry weight (Table 4, Fig. 2).
5.  The major end products of fermentation were identified as propionate and acetate. Both are excreted in substantial amounts (Table 5).
6.  The amount of anaerobic end products equals the amount of glycogen metabolized (Table 6).
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2.
1.  The activity of tympanal high- and low-frequency receptors in the migratory locustLocusta migratoria was recorded with glass capillary microelectrodes, and Lucifer Yellow was then injected through the microelectrode to reveal the cells' metathoracic projections.
2.  A photodetector device was used to monitor the abdominal respiratory movements, which caused clearly visible deflections of the tympanal membrane.
3.  The auditory receptors respond not only to sound stimuli but also to the respiratory movements; these phasic (Figs. 1–3) or tonic (Fig. 4) responses are especially pronounced during the inspiration and expiration movements, and less so during the constriction phases.
4.  The magnitude of the response to sound depends on the phase of the stimulus with respect to the respiratory movements. At certain phases sound elicits no response at all (Fig. 5).
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3.
In response female pheromone the male gypsy moth flies a zigzagging path upwind to locate the source of odor. He determines wind direction visually. To learn more about the mechanism underlying this behavior, we studied descending interneurons with dye-filled micro-electrodes. We studied the interneuronal responses to combinations of pheromone and visual stimuli.
1.  We recorded 5 neurons whose directionally selective visual responses to wide field pattern movement were amplified by pheromone (Figs. 2–6).
2.  The activity of the above neurons was more closely correlated with the position of the moving pattern than with its velocity (Fig. 4).
3.  One neuron showed no clearly directional visual response and no response to pheromone. Yet in the presence of pheromone it showed directionally selective visual responses (Fig. 6).
4.  We recorded 4 neurons whose directionally selective visual responses were not modulated by pheromone (Fig. 7), ruling out the possibility that the effect of the pheromone was simply to raise the activity of all visual neurons.
5.  Our results suggest that female pheromone amplifies some neural pathways mediating male optomotor responses, especially the directionally selective responses to the transverse movement of the image, both below and above the animal.
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4.
1.  The actions of GABA on three classes of visual interneurons in crayfish, Procambarus clarkii, medulla externa are examined. The effect of GABA on the visual response is compared to GABA's action on agonist-elicited responses purported to mediate the visual response.
2.  GABA produces a shunting type of inhibition in medullary amacrine cells which is associated with a small depolarization (Figs. 2, 3), a large increase in input conductance (Gn) and a reversal potential close to rest (Fig. 4). GABA is a potent antagonist to the depolarizing action of acetylcholine (ACh) (Fig. 5).
3.  GABA depolarizes dimming fibers (Fig. 2), and the response is mediated by an increase in Gn (Fig. 6). GABA antagonizes the light-elicited IPSP and the hyperpolarizing action of ACh (Fig. 7).
4.  Sustaining fibers (SF) do not appear to have GABA receptors but GABA inhibits the excitatory visual input pathway to the SFs (Fig. 8). Conversely, the GABA antagonist, bicuculline, potentiates the SF light response (Fig. 9).
5.  GABA has at least three different modes of antagonist action in the medulla: i) Increased conductance and depolarization in dimming fibers and medullary amacrine neurons; ii) Decreased chloride conductance in tangential cells; and iii) An inhibitory action on the visual pathway which drives SFs.
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5.
1.  Interactions of cockroaches with 4 different predator species were recorded by videography. Some predators, especially spiders, struck from relatively short distances and usually contacted a cockroach prior to initiation of escape (Table 1, Fig. 3). This touch frequently occurred on an antenna. Cockroaches turned away from the side on which an antenna was touched.
2.  We then measured the success of escape from predators for cockroaches with either cerci or antennae ablated. Only antennal removal caused a significant decrease in the success of escape from spiders (Fig. 5).
3.  With controlled stimuli, cockroaches responded reliably to abrupt touch of antennae, legs or body (Fig. 6). Responses resembled wind-elicited escape: they consisted of a short latency turn (away from the stimulus) followed by running (Figs. 7, 8). However, lesions show that touchevoked escape does not depend on the giant interneuron system (Table 2).
4.  Following section of one cervical connective, cockroaches continued to respond to touching either antenna, but often turned inappropriately toward, rather than away from, stimuli applied to the antenna contralateral to the severed connective (Table 3, Fig. 10).
5.  For certain types of predators touch may be a primary cue by which cockroaches detect predatory attack. Descending somatosensory pathways for escape are distinct from the GI system.
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6.
Conclusions  
(1)  The aminoesters inhibit glucose-stimulated proton extrusion by yeast cells.
(2)  The inhibitory activity depends on aliphatic carbon chain length.
(3)  The inhibition of proton extrusion is concentration-dependent.
(4)  The aminoesters stimulate quinacrine accumulation in vacuoles of yeast cells so they should possess affinities for lysosomes.
This work was supported byKBN grant no. 7 A203 013 07.  相似文献   

7.
The wind-orientation of carrion beetles (Necrophorus humator F.) was studied by use of a locomotion-compensator.
1.  Beetles walking on a horizontal surface for periods of several minutes in a dark environment without an air current and other orientational stimuli seldom keep straight paths. They walk along individually different circular paths (Fig. 1). The mean walking speed is 5.6±1.0 cm/s. The mean of the angular velocity reaches maximally 25 °/s for individual beetles (mean angular velocity of the analysed population of 152 beetles: 1.9±9.3 °/s). The distribution of the mean walking directions of the population shows that the beetles display no preference for one direction (Fig. 3 A). The instantaneous value of the individual angular velocity is independent of the instantaneous walking direction.
2.  During exposure to an air current the individual beetles keep straight and stable courses with any orientation relative to the direction of air flow (Fig. 4). The mean walking directions of 76 individuals point in all directions but there is a weak preference of windward tracks (Fig. 3B).
3.  Wind orientated walking starts at a threshold wind velocity of about 5 cm/s (Fig. 6). The walking tracks straighten with increasing air current velocity. This leads to a narrowing of the distribution of the instantaneous walking directions around the preferred walking direction (Fig. 7C). This narrowing is due to an increase in the slope of the characteristic curve (angular velocity as a function of walking direction) of the wind-orientation system.
4.  Twenty percent of the beetles show a spontaneous change of their anemotactic course during walks of 5 min duration. Neither the time of the change, its position on the track or the direction of the new course are predictable. There is, however, a slight preference for 90±20° changes in the walking direction (Fig. 8).
5.  The antennae (Fig. 9) act as the only sense organs responsible for the wind orientation. The capability for wind orientated walks is lost after ablation of both flagella (Fig. 10).
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8.
The coupling mechanism between the bilaterally paired optic lobe circadian pacemakers in the cricket Gryllus bimaculatus was investigated by recording locomotor activity, under constant light or constant red light, after the optic nerve was unilaterally severed.
1.  The majority (about 70%) of the animals showed a locomotor rhythm with 2 rhythmic components; one freerunning with a period of 25.33 ± 0.41 (SD) h and the other with 24.36 ± 0.37 (SD) h under constant light (Fig. 3A).
2.  Removal of the intact side optic lobe abolished the longer period component (Fig. 4A), while the operation on the operated side caused a reverse effect (Fig. 4B), indicating that the longer and the shorter period components are driven by the pacemaker on the intact and the operated side, respectively.
3.  The activity driven by a pacemaker was inhibited during the subjective day of the contralateral pacemaker (circadian time 0–10, Fig. 5).
4.  The freerunning periods of the two components were not constant but varied as a function of the mutual phase angle relationship (Figs. 3A, 7, 8).
These results suggest that the 2 optic lobe pacemakers weakly couple to one another and that the cricket maintains a stable temporal structure in its behavior through the phase-dependent mututal inhibition of activity and the phase-dependent freerunning period modulation.  相似文献   

9.
Evidence is presented here from experiments on the visual system of the fly that questions participation of the large monopolar cells (LMCs) in the optomotor response.
1.  The response of a directionally-selective motion-detecting neuron (H1) in the lobula plate to small sudden jumps of a grating is directionally-selective (Fig. 1), indicating that at least one of the inputs to each of the elementary movement detectors (EMD) that feed into H1 must deliver a tonic signal. The responses of LMCs to the same stimulus are, however, entirely phasic (Fig. 2).
2.  In dual electrode experiments on Eristalis, injection of current into an LMC does not change the spiking rate of H1. Induction of spiking activity, or injection of current into an LMC, which alters the cell's response to a flash of light from a point source, does not affect the response of H1 to the same flash (Figs. 3, 4).
3.  The temporal properties of LMCs differ markedly from those of the optomotor response and of directionally-selective movement — detecting neurons in the lobula plate (Figs. 6, 9).
4.  There is poor correlation between LMC degeneration and the strength of the optomotor response in a mutant of Drosophila (Fig. 8).
5.  The optomotor response of Drosophila is strongly polarization sensitive, but Drosophila LMCs show no polarization sensitivity (Fig. 11).
While our results do not exclude the participation of the LMCs in the optomotor response, they do indicate that at least one other lamina channel that is tonic and/ or polarization sensitive must be involved.  相似文献   

10.
In the grasshopperChorthippus biguttulus the stridulatory movements of males with surgically manipulated ventral nerve cords were investigated.
1.  The stridulation pattern of animals with a hemisected mesothoracic ganglion was indistinguishable from that of intact animals.
2.  After hemisection of the metathoracic ganglion several animals were still able to stridulate in the species-specific pattern (Figs. 3, 5). Different structural elements of the song, however, were affected to different degrees by this operation. Although the stereotyped up-and-down movements were normal, the rhythm of pauses, which in intact animals are inserted after every third to fourth up- and-down cycle, was disturbed. As a result, the variation of syllable lengths was much higher (Fig. 4).
3.  A prominent feature after hemisection of the metathoracic ganglion was an almost complete loss of coordination between left and right hind legs (Figs. 5–7). Only in the coarse structure of the song (e.g. the beginning and termination of song sequences) was a correlation of the leg movements still discernible. This was especially obvious in songs of the rivalry type and in precopulatory kicking movements (Fig. 8).
4.  If in addition to hemisection of the metathoracic ganglion one of the neck connectives was transected the animals stridulated only with the hind leg ipsilateral to the intact connective (Fig. 11).
5.  Even after hemisection of both the meso- and metathoracic ganglia, animals were able to produce the species-specific stridulation pattern (Fig. 9).
6.  In animals with hemisected metathoracic ganglia and both connectives between pro- and mesothoracic ganglia transected, components of the species-specific pattern could be induced by current injection into the mesothoracic ganglion (Fig. 10).
7.  These results suggest that the stridulation rhythm-producing neuronal network is composed of hemisegmental subunits. A hemiganglionic structure of rhythm generators might reflect the ancestral organization of locomotion-controlling networks.
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11.
1.  We studied the response of plurisegmental interneurons in the suboesophageal ganglionic mass of female spiders (Cupiennius salei) to male vibratory courtship signals.
2.  The opisthosomal vibrations (low frequency component) and the pedipalpal percussions (high frequency component) are processed in parallel by interneuron type I and type II, respectively (Figs. 3, 7).
3.  Type III, IV and V interneurons represent the macrostructure of the male courtship signals (Figs. 8, 9, 10), i.e. the beginning and the end of a series (type III, V) or the end of the series only (type IV). The macrostructure is known to influence the response probability of the female. The spontaneous bursting activity of a type VI neuron undergoes slow and long lasting changes upon stimulation with natural courtship signals (Fig. 11).
4.  Many interneurons responded to natural signals but not to behaviourally effective computer models. This is presumably due to the lack of spectral complexity of the model compared to natural signals. Differences in the natural conspecific and heterospecific signals, however, are represented by the neuronal response (Fig. 3).
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12.
1.  Certain species of tiger moths emit clicks when stimulated by bat-like sounds. These clicks are generated by modified thoracic episterna (tymbals) (Fig. 1) and constitute a rhythmic behaviour activated by simple sensory input.
2.  Tymbal periods are indirectly related to stimulus intensity and periods (Fig. 3). Moths initiate sounds with the tymbal opposite to the stimulated ear and once a sequence commences it continues in an undisrupted fashion.
3.  The tymbal is innervated by a pleural branch (IIIN2a) of the metathoracic leg nerve, a similar anatomy to that in the unmodified episterna of silent moths (Fig. 5). Backfills of the IIIN2a in Cycnia tenera reveal sensory fibres and a cluster of 5–9 motor neurons with densely overlying dendritic fields (Fig. 6).
4.  Extracellular recordings of the IIIN2a reveal a large impulse preceding each tymbal sound (Fig. 7). I suggest that this impulse results from the synchronous firing of 2–3 motor neurons and is the motor output of the tymbal central pattern generator (CPG). The spikes alternate (Figs. 9, 10) and are bilaterally co-related (Fig. 11) but with an phase asymmetry of 2–3 ms (Fig. 12).
5.  Normal motor output continues in the absence of tymbal sounds (Fig. 13) and when all nerve-tymbal connections are severed (Fig. 14, Table 1) therefore this CPG operates independent of sensory feedback. A model is proposed for the tymbal circuitry based upon the present data and the auditory organization of related noctuid moths (Fig. 15). I propose that the tymbal response in modern arctiids evolved from either flight or walking CPGs and that preadaptive circuitry ancestral to tymbal movements still exists in modern silent Lepidoptera.
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13.
1.  The cochlea of the horseshoe bat,Rhinolophus ferrumequinum, was frequency mapped by exposing for 30 min to one or two continuous pure tones of intensities between 70 and 110 dB SPL. The evaluation was made by differentiating between normal and swollen nuclei of the outer hair cells (OHC) of the organ of Corti and by measuring the diameter of the nuclei of the OHC.
2.  In control animals the radial diameter of the OHC nuclei varies systematically from a mean of 2.85 m at the base to 3.2 um at the apex (Fig. 1).
3.  All frequencies used for exposure were normalized to the resting frequency (FR), which is the frequency of the pure tone component of the orientation sound in a non-flying bat. The individual FR lay between 82.6 and 83.3 kHz.
4.  For analysing the small frequencies between 83.0 to 86.0 kHz in which relevant echoes occur, 3.15 mm length of the basilar membrane is used, about the same length as for the octaves from FR/4 to FR/2 (2.85 mm) and from FR/2 to FR (3.2 mm) (Fig. Ca, b).
5.  The discontinuity of the mechanical data at 4.5 mm of the length of the basilar membrane (part I of this paper) coincides with FR and the less pronounced discontinuity at 7.8 mm coincides with FR/2.
6.  Location and mechanism of the auditory filter are discussed.
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14.
1.  The self-adapting effects of chemical backgrounds on the response of primary chemoreceptor cells to superimposed stimuli were studied using lobster (Homarus americanus) NH4 receptor cells.
2.  These receptors responded for several seconds to the onset of the backgrounds, and then returned to their initial level of spontaneous activity (usually zero). The strongest response always occurred only during the steepest concentration change; the response then decayed back to zero or to the earlier spontaneous firing level, while the background concentration was still rising, and remained silent during the entire time that the background was maintained constant (20–30 min) (Fig. 2).
3.  Exposure to constant self-adapting backgrounds eliminated the responses of NH4 receptor cells to stimuli of concentration lower than the background, and reduced the responses to all higher stimulus concentrations tested by a nearly equal amount. This resulted in a parallel shift of the stimulus-response function to the right along the abscissa (Figs. 3 and 4).
4.  Since the response threshold was completely re-set by adaptation to backgrounds, NH4 receptors seem to function mostly as detectors of relative rather than absolute stimulus intensity across their entire dynamic range: the response to a given stimulus-to-background ratio remained the same over 3 log step increases of background concentration (Fig. 6).
5.  As in other sensory modalities, a parallel shift of response functions appears to be an important property of chemoreceptor cells, allowing for this sensory system to function over a wider stimulus intensity range than the instantaneous dynamic range of individual receptor cells.
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15.
The wind-orientated walk of carrion beetles Necrophorus humator F. was analysed under closed-loop conditions with a walking compensator and under openloop conditions with a paired tread wheel (Fig. 1).
1.  On the walking compensator an animal runs stable courses with a preferred direction relative to an air current (velocity =; 100 cm/s, Fig. 2B-D). A change in the air-current direction causes a corresponding adjustment of the mean walking direction (Fig. 3). Such course adjustment works best for changes in the air-current direction by an absolute value of 90° (Table 2).
2.  Under closed-loop conditions the animal shows deviations of less than ± 45° around its preferred direction relative to the wind (Fig. 2B-D). The characteristic curve which describes the animal's angular velocity as a function of the animal's walking direction relative to the air-current stimulus is therefore revealed only in this angular range (Fig. 3, top).
3.  Under open-loop conditions, however, complete characteristic curves can be obtained because the animal's walking reaction in response to any given angle of air-current stimulus is measurable on the paired tread wheel (Fig. 4). The characteristic curves are approximately sinusoidal functions. They can either show a shift parallel to the ordinale by a superimposed direction-independent constant angular velocity alone or, at the same time, they can independently exhibit an angular shift along the abscissa (Fig. 5).
4.  The walking tracks straighten with increasing air-current velocity (Fig. 6A, insets), i.e. the animal more rapidly compensates deviations from a preferred course. This corresponds to higher amplitudes of the characterisic curve and steeper slopes at the negative zero-crossing point under open- as well as under closed-loop conditions (Fig. 6).
5.  Walking in an air-current field can be explained by a model of the course control system using a feedback loop (Fig. 7). This model operates according to a sinusoidal characteristic function on which is superimposed a Gaussian white noise process of angular velocity which is independent of walking direction. The model produces realistic walking tracks in an air-current field (Fig. 8).
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16.
Locusts (Locusta migratoria) were flown in a flight simulator which converts yaw torque into angular motion of the visual environment (Fig. 1). The modalities and the time-course of steering behavior under these closed-loop conditions have been investigated.
1.  Locusts flying under visual closed-loop conditions stabilize their visual environment by performing correctional steering manoeuvres. Besides torque production, due to differential wing movements and ruddering, correctional steering also involves head movements (Fig. 6).
2.  During open-loop steering, ruddering and yaw torque begin some 60 ms after the onset of the visually simulated deviation from course. Head movements occur some 90 ms after stimulus onset, i.e. some 30 ms later than yaw torque (Figs. 3, 5) and therefore do not initiate thoracic steering outputs.
3.  Open- and closed-loop correctional steering do not differ in their behavioral components or temporal organization (Figs. 2, 6, Table 1).
4.  In the absence of major disturbances, correctional steering under closed-loop conditions is performed with minimal ruddering (only a few degrees in amplitude), that probably produces little or no aerodynamic drag (Fig. 6).
5.  Locusts prevented from moving their heads still stabilize their visual environment in the closed-loop situation. However, the precision of steering is affected by this constraint (Figs. 8, 9, 10, 12). Head immobilization also alters the temporal coordination of correctional steering (Figs. 7, 11).
6.  These results show that head movements, in addition to their generally accepted role in vision improvement, also contribute to the precision and temporal coordination of correctional flight manoeuvres. The mechanism is partly via proprioceptive feedback.
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17.
1.  We tested the long-standing hypothesis that female frogs are attracted to the sound of a chorus of conspecific males from a distance. We studied the barking treefrog (Hyla gratiosa) because the location of choruses is unpredictable; thus, chorus sound indicates the presence of conspecific males as well as the location of a suitable breeding site.
2.  We measured the sound pressure level (SPL in dB re 20 Pa) in the 500 Hz octave band at various distances from choruses. The primary spectral peak in the advertisement call of this species is 400–500 Hz.
3.  The pattern of chorus sound attenuation in the 500 Hz band at two different sites was very similar and generally followed the pattern expected from geometrical spreading from a point source (Fig. 3). At one of the sites the SPL measured near ground level was always higher than that at a point 1 m above the ground (Fig. 3).
4.  Spectral analyses of the chorus sound at different distances showed that the low-frequency spectral peak in the range of 400–500 Hz was a prominent component, especially at 80–160 m (Figs. 1, 4). Amplitude peaks that corresponded to individual calls ofH. gratiosa and other species were also evident in oscillograms of recordings made at 160 m (Fig. 1).
5.  Gravid females oriented and moved toward a source of conspecific chorus sounds (originally recorded at 160 m from the pond) played back at 38–40 dB SPL in the 500 Hz octave band (Fig. 1, Table 1). Background noise levels were 43–47 dB SPL (C-weighted) and 24–25 dB SPL in the 500 Hz octave band.
6.  In a two-stimulus, choice experiment, females ofH. gratiosa always chose the source of a mixed chorus (H. gratiosa andH. cinerea) sound with conspecific males to a source of a pure chorus sound ofH. cinerea (Fig. 2, Table 2).
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18.
1.  While collecting nectar in hovering flight the European hawk moth Macroglossum stellatarum efficiently regulates its distance relative to flowers that are shaken by wind. This can be demonstrated in laboratory experiments by moving dummy flowers (blue cardboard disks) towards and away from the feeding animal (Fig. 1).
2.  Distance regulation is predominantly mediated by visual cues. Mechanoreceptors on the proboscis appear to contribute little to the response.
3.  Movements of dummy flowers can be simulated by expanding and contracting a pattern projected onto a screen. With this technique we investigated the dynamical properties of the servo mechanism underlying distance regulation. The system behaves as a bandpass filter with corner frequencies of 0.15 and 5 Hz (Figs.2,3).
4.  When a high-speed ramp-like movement of the flower is simulated, there is an asymmetry in the response. During simulated approach the reaction is phasic-tonic with a pronounced overshoot at the beginning, during simulated retraction it remains tonic (Fig.5B,C).
5.  During distance regulation the animals compensate for the speed of the edge of the projected pattern. Distance regulation improves substantially when the number of stimulated elementary movement detectors is increased through increasing the number of contour lines by projecting concentric rings instead of a homogeneous disk (Figs.7, 8).
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19.
1.  Filiform hairs of various lengths on the cerci of adult crickets vibrate in a sound field. These movements were measured with a photodetector for sound frequencies from 10 Hz to 200 Hz in the species Acheta domestica, Gryllus bimaculatus and Phaeophilacris spectrum.
2.  With low air-particle velocities, the hair shafts were deflected sinusoidally from their resting position, without bending or secondary oscillations (Figs. 2 A, 3 A). At higher velocities (from ca. 80 mm/s peak velocity, depending on the properties of the individual hairs), the shaft struck the cuticular rim of the socket in which the base of the hair is seated (Fig. 2B). This contact was made at an average angular displacement from the resting position of 5.16°±1.0°.
3.  The best frequencies of the hairs were found to be between 40 Hz and 100 Hz (Fig. 5A). The slope of the amplitude curve for constant peak air-particle velocity at frequencies below the best frequencies was between 0 and 6 dB/octave. Long hairs had smaller slope values than short hairs (Fig. 5C).
4.  At its best frequency the ratio of maximal tip displacement of a hair to the displacement of the air particles in the sound field was between 0.2 and 2. Only a small number of hairs (2 out of 36) showed tip displacements exceeding twice the air-particle displacement. The values of maximal angular displacement were not correlated to hair length (Fig. 5 B).
5.  The angular displacement of the hairs was phase shifted with respect to the air-particle velocity by 0° to +45° (phase lead) at sound frequencies around 10 Hz and by -45° to -120° (phase lag) at 200 Hz (Figs. 3C, 4B). At a particular frequency long hairs tended to have larger phase lags than shorter hairs (Fig. 5D).
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20.
3DFS is a 3D flexible searching system for lead discovery. Version 1.0 of 3DFS was published recently (Wang, T.; Zhou, J. J. Chem. Inf. Comput. Sci., 1998, 38, 71–77). Here version 1.2 represents a substantial improvement over version 1.0. There are six major changes in version 1.2 compared to version 1.0.
1.  A new rule of aromatic ring recognition.
2.  The inclusion of multiple-type atoms and chains in queries.
3.  The inclusion of more spatial constraints, especially the directions of lone pairs.
4.  The improvement of the query file format.
5.  The addition of genetic search for flexible search.
6.  An output option for generating MOLfiles of hits.
Besides the above, this paper supplies:
1.  More query examples.
2.  A comparison between genetic search and Powell optimization.
3.  More detailed comparison between 3DFS and Chem-X.
4.  A preliminary application of 3DFS to K+ channel opener studies.
Supplementary material to this paper is available in electronic form at http://dx.doi.org/10.1007/s0089490050231  相似文献   

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