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181.
182.
The ester-hydrolyzing or lipase actions of extracts of whole rats whose ages ranged from 3 days before birth to 3 years 15 days were tested on ten simple esters by the method described in previous papers. The results are presented in the form of curves, both as absolute actions and as relative actions on the different substrates. The "pictures" of the relative actions changed progressively with increasing age of the rat. For the embryo and the youngest rats, the curves approached those given by the Flexner-Jobling rat carcinoma and by a number of tumors of human origin, changing to a type characteristic of the adult rat, and appearing to revert again to some extent to the embryonic type for the oldest rats. The changes in the actions on individual esters and the relative changes in the actions on different esters are discussed in detail. The greatest increases in actions as the rats became older were found with methyl and ethyl butyrates; at the same time that the actions on some of the other esters were also found to change in characteristic ways. Similar experiments with the protease actions of the extracts of whole rats of different ages on three protein preparations did not give differences similar to those found for the lipase actions. The probable reasons for these observed differences in the two sets of enzyme actions are discussed.  相似文献   
183.
184.
Superoxide dismutases in photosynthetic organisms at different evolutionary levels were characterized using the criterion that the Cu,Zn-enzyme is sensitive to cyanide while the Mn- and Fe-enzymes are insensitive. The effect of the antibody against spinach Cu,Zn-superoxide dismutase was also tested as a means of distinguishing the several forms of the enzyme. Superoxide dismutase activity in extracts from photosynthetic bacteria, prokaryotic algae (blue-green algae), and eukaryotic algae (red, green, and brown algae, diatoms, Euglena, and Charophyta) were insensitive to cyanide and to the antibody, suggesting the presence of the Fe- and/or Mn-enzymes and the absence of the Cu,Zn-enzyme. In contrast, ferns, mosses, and seed plants including gymnosperms and angiosperms contained the Cu,Zn-superoxide dismutase in addition to the cyanidein-sensitive enzyme in soluble or bound form. Although an aerial green alga lacks the Cu,Zn-superoxide dismutase, aquatic angiosperms and ferns, like other land plants, contain this form of superoxide dismutase. Thus the distribution of the Cu,Zn-superoxide dismutase does not reflect the habitat but, rather, the phylogeny of the organism. The relation between the oxygen concentration in the atmosphere and the appearance of various forms of superoxide dismutase during the evolution of photosynthetic organisms is discussed.  相似文献   
185.
This paper describes a 12-year-old Japanese boy with coarctation of the aorta, renal hypoplasia, Turner/ Noonan surface anomalies, and a 46,XY karyotype. Although the patient might represent an exceptional case of Noonan syndrome, the combination of the somatic stigmata appears to be consistent with a mutation of the putative lymphogenic gene(s) for Turner somatic stigmata. Received: 24 June 1995 / Revised: 28 September 1995  相似文献   
186.
In chloroplasts O2 is photoproduced via the univalentreduction of O2 in PSI even under conditions that are favorablefor photosynthesis. The photogenerated O2 is disproportionatedto H2O2 and O2 in a reaction that is catalyzed by superoxidedismutase (SOD). The H2O2-scavenging ascorbate peroxidase isbound to the thylakoid membranes at or near the PSI reactioncenter [Miyake and Asada (1992) Plant Cell Physiol. 33: 541],and the primary product of oxidation in the peroxidase-catalyzedreaction, the monodehydroascorbate radical, is photoreducedto ascorbate in PSI in a reaction mediated by ferredoxin [Miyakeand Asada (1994) Plant Cell Physiol. 35: 539]. Therefore, SODshould be localized at or near the PSI complex. We report herethe microcompartmentalization of the chloroplastic CuZn-SODon the stromal-faces of thylakoid membranes where the PSI-complexis located. Spinach leaves were fixed and substituted by a rapidfreezing and substitution method that allows visualization ofintact chloroplasts. The embedded sections were immuno labeledwith the antibody against CuZn-SOD by the immunogold method.About 70% of the immunogold particles were found within 5 nmfrom the surface of the stromal-faces of thylakoid membranes.Of these particles, about 40% were found at the ends and marginsof the grana thylakoids and 60% were found on the stromal sideof the stromal thylakoids. From these results, the local concentrationof CuZn-SOD on the stroma-facing surfaces of the thylakoid membraneswas estimated to be about 1 mM. The effect of the microcompartmentalizationof CuZn-SOD on the scavenging of superoxide radicals is discussed. (Received November 25, 1994; Accepted February 23, 1995)  相似文献   
187.
Although sex chromosome aberrations are frequently associated with statural changes, the underlying factors have not been clarified. To define the factors leading to the statural changes, we took the following three steps: (1) determination of the mean adult height in non-mosaic Caucasian patients with sex chromosome aberrations reported in the literature (assessment of genetic height potential); (2) assessment of the validity of factors that could influence stature; and (3) correlation of the mean adult height with the effects of specific growth-related factors. The results indicate that the adult height in patients with sex chromosome aberrations may primarily be defined by the dosage effect of pseudoautosomal and Y-specific growth genes, together with the degree of growth disadvantage caused by alteration of the quantity of euchromatic or non-inactivated region.  相似文献   
188.
The hepatitis E virus (HEV) causes a common infectious disease that infects pigs, wild boars, deer, and humans. In most cases, humans are infected by eating raw meat. Some essential oils have been reported to exhibit antiviral activities. In this study, in order to investigate the anti-HEV properties of essential oils, the immunoreactivities of HEV antigen proteins against the relevant antibodies were analyzed after the HEV antigens underwent treatment with various essential oils. The essential oils extracted from the tea tree, which was previously reported to exhibit antiviral activity, lavender, and lemon had strongly reduced activity. We found that treatment with the essential oil prepared from Sakhalin spruce was associated with the strongest reduction in immunoreactivity of HEV antigen protein(s) among the tested substances. The main volatile constituents of Sakhalin spruce essential oil were found to be bornyl acetate (32.30 %), α-pinene (16.66 %), camphene (11.14 %), camphor (5.52 %), β-phellandrene (9.09 %), borneol (4.77 %), and limonene (4.57 %). The anti-HEV properties of the various components of the essential oils were examined: treatment with bornyl acetate, the main component of Sakhalin spruce oil, α-pinene, the main component of tea tree oil, and limonene, the main component of lemon oil, resulted in a strong reduction in HEV antigen immunoreactivity. These results indicate that each main component of the essential oils plays an important role in the reduction of the immunoreactivity of HEV antigen protein(s); they also suggest that Sakhalin spruce essential oil exhibits anti-HEV activity. In a formulation with the potential to eliminate the infectivity of HEV in foodborne infections, this essential oil can be applied as an inactivating agent for meat processing and cooking utensils, such as knives and chopping boards.  相似文献   
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