首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
The following procedure for staining Negri bodies in sections is based on methods previously described by MacNeal, by Haynes, and by Richter:

Fixation:
  1. 1. Zenker's solution 4 hours at 37°C or Dominici's 3 hours.

  2. 2. 70% alcohol, 12 to 18 hours at room temperature.

  3. 3. 80% alcohol, about 5 to 6 hours.

  4. 4. 90% alcohol, about 4 to 6 hours.

  5. 5. Absolute alcohol about 16 hours.

  6. 6. Ether and absolute alcohol aa, about 8 hours.

  7. 7. 16 to 24 hours in the following mixture: celloidin 1 g., methyl salycilate 25 cc., abs. alcohol 25 cc., ether 25 cc.

  8. 8. Chloroform and paraffin, 2 to 3 hours.

  9. 10. Paraffin, 1 to 1 1/2 hours.

  10. 11. Embed.

staining:
  1. 1. Cut sections 4 to 5 μ.

  2. 2. Bring section to water and cover with Lugol's iodine for 10 minutes.

  3. 3. Decolorize with a 2% sodium thiosulfate (hypo).

  4. 4. Wash thoroly with water.

  5. 5. Cover with a mixture of equal parts of 0.5% phloxine and 1% eosin Y (National Aniline brand) and leave for 15 minutes.

  6. 6. Wash with water and stain 2 to 5 minutes in 0.1% azure B (National Aniline).

  7. 7. Wash with 96% alcohol and decolorize in a mixture of 2 parts absolute alcohol with 1 part clove oil, ordinarily for not more than 1/2 to 1 minute.

  8. 8. Dehydrate rapidly, clear, and mount in Yucatan Elemi.

  相似文献   

2.
3.
Abstract

The Influence of Short Periods of Lighting with Different Wavelengths on the Orcadian Changes of the Enzymatic Digestive Activities in Palaemon serratus (Crustacea, Natantia)

The effect of light on the circadian rhythms of digestive activities in the Shrimp Palaemon serratus have been studied.

  1. Continuous darkness leads in a few days to a disappearance of the variations of the circadian rhythms of digestive enzymes while these rhythms go on in continuous light.

  2. Short (1 or 2 hrs) and low intensity flashes of white light are effective in bringing on the reappearance of rhythmic variations in darkness.

  3. We have been able to establish an isoquantic spectrum of action of the light. Two values of wavelength appears to account for a maximum sensibility of the shrimp: one in ultraviolet light and an other one, more important, in the green (λ=544 nm).

  4. In green light it is possible to obtain the same effect of light by decreasing the time of stimulation to 5 or 10 mn and in increasing the total quantity of energy. Significant responses are obtained with total energy greater than 10000 pE. cm‐2.

  相似文献   

4.
Abstract

ACTION OF LIGHT ON SEEDLING GROWTH IN A YELLOW-GREEN MUTANT OF TRITICUM DURUM DESF. — Dry grains of Triticum durum cv. « Cappelli » and its radiation-induced yellow-green mutant were sown in sand in four environment, different for light conditions (daylight, artificial light, ultraviolet rays, darkness), having all the same temperature (23°C.). Seven days after sowing, the following data were registered: a) growth (in cm.) of the shoot and of the longest root; b) fresh weight (in gr.) of shoots and roots; c) water content of shoots and roots.

The following main results were obtained:
  1. the yellow-green mutant always shows less growth and less weight increase than normal « Cappelli », with the exception of the seedlings grown at daylight, which have shorter shoots and longer roots than the normal « Cappelli » but the same weight:

  2. artificial light, besides depressing the growth of the roots of the yellow-green mutant, which becomes green under these conditions, induces a remarkable decrease in the water content of the roots of the two wheats.

  相似文献   

5.
Abstract

The effect of sugars on growth of isolated cotyledons from germinating castor bean seeds. — The presence of sugars in the medium induces a number of biochemical and physiological changes in the cotyledons isolated from germinating castor bean seeds. In the present research, the extent and the mechanism of the effect of sugars on growth of the isolated cotyledons was investigated.

The results achieved may be summarized as follows:

  • Sucrose markedly stimulates the growth (as increase of fresh weight) of the isolated cotyledons; its action is already apparent when using a 10-2M concentration and reaches a maximum (stimulation by about 400%) for the concentration between 5.10-2M and 1,5.10-3M. The increase of sucrose induced growth is due in almost equal proportions to water uptake and to increase of dry weight.

  • The difference (Δ P.O.) between the osmotic pressure (P.O.) of the cell sap and that of the external medium is markedly higher for the cotyledons treated with sucrose (7–8 atm.) than the Δ P.O. of cotyledons incubated in water.

  • Analyses of cell contents in sugars show that sucrose is taken up by the cotyledon cells against a concentration gradient. The increase of the difference of osmotic pressure between cotyledon and the external medium is satisfactorily accounted for by this active accumulation of sugars.

  • When mannitol is added to the incubating medium in addition to sucrose, the active uptake of sugar is not disturbed; but the effect of sucrose on growth decreases, and it completly disappears when mannitol concentration in the medium is such, to make the value of Δ P.O. for the cotyledons in sucrose plus mannitol equal to the Δ P.O. for the cotyledons incubated in water.

  • Besides increasing the P.O. in the cotyledons, sucrose markedly accelerates the decrease of free aminoacid in the isolated cotyledons.

  • Auxin (β—indolacetic acid) does not stimulate, or stimulates weakly, growth of the cotyledon incubated in water; some stimulation can be observed only when sucrose is present. Gibberellic acid stimulates growth (though to a much lower extent than sucrose) in the cotyledons in water, while its action does no longer appear when sugar is present.

The decrease of free aminoacid together with other observations, indicates an effect of sucrose on protein metabolism; however, growth stimulation by sucrose seems to depend essentially on its active accumulation - against a concentration gradient - and thuson the increase of osmotic pressure. It is thus suggested that in these tissues osmotic pressure is the most important factor in limiting growth by cell extension.  相似文献   

6.
  1. The catalase activity of Candida tropicalis pK 233 was induced by hydrocarbons but not by glucose, galactose, ethanol, acetate or lauryl alcohol.

  2. The induction of the catalase activity depending upon hydrocarbons was sensitive to cycloheximide but not to chloramphenicol.

  3. Glucose repressed strongly the induction of the catalase activity by hydrocarbons but galactose did not affect seriously.

  4. When C. tropicalis was incubated with hydrocarbons, the appearance of microbodies was observed electronmicroscopicaliy.

  相似文献   

7.
In Fortführung seiner Untersuchungen über neotropische Acanthocinini veröffentlicht der Verfasser hiermit Beschreibungen von folgenden neuen Gattungen:
  • Nyssodrysilla nov. gen. mit N. irrorata (Melzer) aus Brasilien als Generotype, N. viliata (Melzer), comb, nov., aus Brasilien und N. lineata nov. spec, aus Peru.

  • Nyssodrysola nov. gen. mit N. stictica nov. spec. aus Peru als Generotype.

  • Sciadosurus nov. gen. mit S. albobrunneus nov. spec. aus Peru als Generotype.

  • Acarinozineus nov. gen. mit A. striatus nov. spec. aus Peru als Generotype und A. spinicornis nov. spec, aus Mexiko.

  • Alcathousites nov. gen. mit A. chaclacayoi nov. spec. aus Peru als Generotype.

  • Xylergatina nov. gen. mit X. pulcher (Lane) aus Peru als Generotype.

  • Xylergatoides nov. gen. mit X. asper (Bates) aus Brasilien und Argentinien als Generotype.

Ferner werden revidiert die Gattungen:
  • Xylergates Bates, Generotype X. lacteus (Bates), mit Beschreibung der beiden neuen Arten X. elaineae aus Peru und X. dorotheae aus Britisch‐Guayana.

  • Chaetanes Bates, Generotype C. setiger (Bates), mit Beschreibung der drei neuen Arten C. costulatus aus Peru, C. nigrobasalis aus Brasilien und C. apicalis aus Französisch‐Guayana.

  • Wo es erforderlich ist, sind Bestimmungstabellen gebracht und die Arten abgebildet.

  相似文献   

8.
Abstract

This study evaluated remediation of the herbicide sulfentrazone in soils with three different mineralogies (kaolinite, hematite, and gibbsite) and three remediation sulfentrazone treatments (Canavalia ensiformis L., Crotalaria juncea L., and natural attenuation). This study was conducted in a factorial scheme, in triplicate with randomized block design. Sulfentrazone was applied at 0 and 400?g ha?1. We analyzed sulfentrazone residue in the soils by high-performance liquid chromatography and confirmed the results with bioassays of Pennisetum glaucum. Herbicide movement was greater in the kaolinitic soil without plant species. The retention of herbicide in the kaolinitic soil occurred in larger quantities in the 0–12?cm layer, with higher levels found in the treatments with plants. In the hematitic soil with C. juncea, all applied herbicides were concentrated in the 0–12?cm layer. In the other hematitic soil treatments, sulfentrazone was not detected by chemical analysis at any soil depth, although in many treatments, it was detected in the bioassay. Phytoremediation was more efficient with C. ensiformis grown in gibbsitic soil, reducing the sulfentrazone load by approximately 27%. Natural attenuation was more efficient than phytoremediation in oxidic soils due to soil pH and texture soils favored microbial degradation of the compound.
  • Highlights
  • The influence of soil mineralogy of herbicide sulfentrazone retention was evaluated.

  • Canavalia ensiformis and Crotalaria juncea were evaluated as phytoremediation plants.

  • Kaolinite soils presented great movement of sulfentrazone in the soil.

  • Natural attenuation is more efficient in oxide soils than phytoremediation.

  相似文献   

9.
Abstract

Inactivation and riactivation of enzymes in endosperms of castor bean seeds. — On the basis of previous results, the possibility has been investigated of the reversible interconversion of active and inactive form of enzymes in castor bean seeds, during their development.

The results described here indicate that:

  1. the activity of some glycolytic enzymes increases greatly (81% and 400% increase of, respectively, Gl-6-P-dehydrogenase and aldolase) upon incubation of dry seeds for few hours at 4 °C.

  2. The decrease of enzyme activity upon dehydration of seeds and the increase during the subsequent imbibition can be shown reproducibly.

  3. This same observation is made for oxygen uptake.

These results are interpreted to indicate the reversible inactivation of enzymes caused by dehydration of seeds.  相似文献   

10.
11.
Riassunto

L'A. ha studiato l'embriogia della Vinea difformis Pourr. ed ha potuto stabilire che:

  1. l'archisporio è pluricellulare e possono svilupparis talvolta pi[ugrave] cellule madri;

  2. normalmente solo una cellula madre arriva a maturità;

  3. delle quattro megaspore solo una è fertile e precisamente la pi[ugrave] calazale;

  4. lo sviluppo del gametofito è del tipo Normale cioè Monomegasporiale con oangio emisporiale.

Ha inoltre risontrato una anomalia di sviluppo constituita da un gametofito binucleato abnorme per ritardo delle divisioni nucleari cispetto all'acerescimento che è quello di un gametofito ottonucleato.  相似文献   

12.
  1. l-Aspartate was found to replace l-asparagine in the protective action from acid inactivation of l-asparaginase (EC 3.5.1.1) produced by Escherichia coli A–1–3 and at the same time to inhibit the proteolytic inactivation by α-chymotrypsin.

  2. l-Asparaginase changed in its chromatographic properties in the presence of l-aspartate and became to be absorbed on the CM Sephadex column.

  3. The sedimentation patterns of l-asparaginase at pH 3.5 were identical either in the presence or absence of l-aspartate, showing partial dissociation. But the reversibility to the active state was observed only in the enzyme dissolved in the solution containing l-aspartate.

  4. l-Aspartate did not prevent the enzyme either from the dissociation into subunits or from decrease in the activity by urea.

  5. High concentration of l-aspartate was shown to inhibit the l-asparagine hydrolysis reaction.

  6. l-Aspartate was suggested from ORD measurements to cause changes in the higher structure as well as the ionic properties or proteolytic inactivation.

  相似文献   

13.
Abstract

SOME INVESTIGATIONS ON THE BEHAVIOUR OF EXCISED EMBRYOS OF TRITICUM DURUM CV. « CAPPELLI », COMING FROM NORMAL GRAINS AND YELLOW BERRIES. — Excised embryos of Triticum durum cv. « Cappelli », coming from normal grains and yellow berries, soaking in distilled water for 24 hours, were brought up for 6 days in petri dishes, on a 1% solution of agar + glucose, at the constant temperature of 23°C, at the light of a common germicidal lamp. As controls, normal grains and yellow berries were utilized, placed in petri dishes each containing a piece of filter paper moistened with distilled water. After 6 days, the seedlings (measured the shoot and the longest root) were transferred to a greenhouse in sand, at daylight (average temperature: 16°-18°G.). After 14 days, the shoot and the longest root of each seedling coming from the sand cultures were measured.

The following results were obtained:
  1. control seedlings: after 7 (1 + 6) days, the normal seedlings grow more than those coming from yellow berries and the shoots grow as the roots (see MELETTI e ONNIS 1961 a, b e c); after 21 days, the situation of the control seedlings is again completely regular (normal shoots are longer);

  2. seedlings coming from excised embryos: differences of growth are not here, neither after 7 nor after 21 days, among seedlings coming from normal grains and yellow berries.

These data should allow to conclude that the embryos, coming from normal grains and yellow berries, grow in the same way. But the limits of the utilized technique (want of balance in the relations between shoot and root, low survival of the seedlings coming from the excised em bryos, which grow too little in respect of the controls) suggest to carry into other investigations on the same subject.  相似文献   

14.
  1. The incorporation of 14C-methanol, 14C-formaldehyde, 14C-formate and 14C-bicarbonate into a methanol-utilizing yeast, Candida N–16, was examined by paper-chromato-graphy and radioautography.

  2. At the earliest time period examined, the highest percentage of radioactivity fixed from 14C-methanol or 14C-formaIdehyde into methanol-grown cells was found in fructose phosphate. The percentage distribution of radioactivity in fructose phosphate decreased as time elapsed. The radioactivity fixed from these compounds into glucose-grown cells was negligible compared with that fixed into methanol-grown cells.

  3. The incorporation of 14C-formate into methanol-grown cells was extremely low. The highest percentage of radioactivity fixed for short time incubation was found in serine. The incorporation pattern of glucose-grown cells was similar to that of methanol-grown cells.

  4. At the earliest time period, over 70% of radioactivity fixed from 14C-bicarbonate into methanol- or glucose-grown cells was found in aspartate.

  5. These results suggest that in Candida N–16 methanol is specifically assimilated by a route with hexose phosphate as a primary stable intermediate.

  相似文献   

15.
Inmunoglobulin isolated from human sera, be it by the cryo-alcohol, rivanol, multi membrane electrodecantation or polyethylene glycol process, alvays contains denatured material. This may result from the influence either singly or in combination, of acme of the follwing factors:
  1. inefficiency of the purification procedure;

  2. surface denaturation;

  3. imperfect freeze-drying of the final product; and

  4. factors yet unknown vhich cause alteration in the immoglobulins or other protein components not ellminated by the purification procedures.

  相似文献   

16.
  1. The 1C conformation was estimated for α-d-galactopyranosiduronic acid moiety of pectic acid in the permethylated derivative dissolved in 1 n NaOD-D2O and in the peracetylated derivative dissolved in dimethyl sulfoxide-d6, and the C1 conformation was estimated for some derivatives of d-galactopyranuronic acid in chloroform-d by NMR spectroscopy.

  2. Random conformation of the whole macromolecule was estimated for pectic acid in water on the basis of no appearance of any induced Cotton effects in the 200 ~ 700 mμ region in the ORD spectra of pectic acid-anionic dye complexes.

  3. The conformation was supported by the fact that the rate of periodate oxidation of pectic acid at 5° was slightly decreased in comparison with that of amylase in 7 m urea solution.

  相似文献   

17.
Gallic acid acts as a precursor molecule to synthesize various tannin molecules. These are plant polyphenols and were proved to be good anti-oxidant, anti-cancerous, anti-inflammatory, anti-microbial compounds. In order to fully exploit prominent biological activities of specific tannins and to develop tannin-based new medicines, it is necessary to obtain their pure preparations with an aim of high yield and specificity. In the present study, gallic acid is synthesized by the hydrolysis of tannic acid using a microbial based transformation process. The microorganism was isolated and identified. The ability of the isolated microorganism to covert tannic acid into gallic acid was determined by HPLC and enzyme production.
  • Highlights
  • The present investigation signifies the role of Enterobacter spp. in various processes:

  • ??To synthesize gallic acid (a precursor for food oxidant such as propyl gallate) and a bacteriostatic antibiotic (trimethoprim).

  • ??To protect the environment from tannery’s discharge through the process of biodegradation.

  • ??To reduce the toxicity of tannins in animal feed.

  相似文献   

18.
During the course of studies on the oxidative metabolism of d-sorbitol by acetic acid bacteria, it was found that d-sorbitol was almost quantitatively converted to 5-keto-d-fructose via l-sorbose by a certain strain of Gluconobacter suboxydans. In addition to 5-keto-d-fructose, three γ-pyrone compounds, kojic acid, 5-oxymaltol, and 3-oxykojic acid, 2-keto-l-gulonate, and several organic acids such as succinic, glycolic, and glyceric acids were confirmed in the culture filtrate of this bacterium.
  • The most suitable carbon source for 5-ketofructose fermentation by Gluconobacter suboxydans Strain 1 was confirmed to be d-sorbitol or l-sorbose using growing and resting cells. d-Fructose had little effect on the formation of this dicarbonylhexose.

  • The optimal pH for the formation from l-sorbose by intact cells was found to be at 4.2.

  • The activity of the pentose phosphate cycle in the resting cells was calculated as 13~17 μatoms/hr/mg of dry cells by the use of the manometric techniques.

  • There was no strain tested so far which could accumulate a large amount of 5- keto-d-fructose from d-sorbitol except this bacterium.

  • The experimental results shown in this paper makes the prediction that a certain dehydrogenating system of l-sorbose is functional in the organism, and the metabolic pathways of d-sorbitol via l-sorbose and 5-keto-d-fructose is proposed.

  相似文献   

19.
  1. Research into the visual shape discrimination abilities of compound‐eyed animals has almost exclusively been limited to insects, the crustaceans having been virtually ignored. The two groups have many dissimilarities, having primarily adapted in different habitats to different lifestyles. Differences may exist in visual systems and visually mediated behavior.

  2. Fiddler crabs (Uca pugilator), without training, differentially approached dissimilar silhouettes presented simultaneously, demonstrating visual discrimination between stationary, geometric shapes of equal‐area. The strength of response was ordered hierarchically: vertical rectangle, horizontal rectangle, triangle, square, circle.

  3. Basic geometric shapes were used to facilitate replication and comparison with research findings from other species.

  相似文献   

20.
Relationship between the chemical constituents of tobacco leaves and the gaseous constituents of cigarette smoke from which K value1) was computed was discussed and the following presuppositions were demonstrated to be correct.

  1. Fibrous substances in tobacco leaves are the main precursors of acetaldehyde, propionaldehyde, acrolein, acetone, methylethylketone, diacetyl, methanol, furan, an unknown compound, No. 6 and an unknown compound, No. 16 in cigarette smoke.

  2. Sugars in tobacco leaves are the main precursors of 2-methylfuran and 2,5-dimethyl- furan in cigarette smoke.

  3. Resinous substances in tobacco leaves are the main precursors of isoprene and an unknown compound, No. 2 in cigarette smoke.

  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号