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191.
The early stages of bacterial settlement on 70:30 copper nickel alloy was followed by scanning electron microsocopy. Two strains of marine bacteria (Pseudomonas sp and Vibrio alginolyticus) isolated from polluted harbour sea water were used. The corrosion behaviour of the alloy was studied through corrosion potential measurements made in sterile and contaminated sea water. According to our results microbial colonisation of the metal surface occurs within the first 24 h for the two bacteria used. Well defined microbial colonies with localised corrosion underneath were seen by SEM after short periods of exposure. Corrosion attack seems to be closely related to passive film modification by the bacterial settlement.  相似文献   
192.
A remarkable population of Carex extensa (Cyperaceae) was found south of Lake Fert? (Neusiedler See) in Hungary in 2012. This species typically occurs in coastal salt marshes in Europe and was hitherto unknown from the Pannonian Basin. The locality is situated in a territory which has been embanked in 1911. Keeping also in mind that the vegetation developed here from reed beds to saline habitats, we conclude that C. extensa reached the salt marshes of the area through long distance dispersal by water birds from the European coast in the last century. Nevertheless, several other maritime littoral species grow in the region, and the possibility that there is a hidden population of C. extensa at another site(s) nearby cannot be excluded. Lake Fert? is often described as the “westernmost steppe lake” and supports one of the richest European inland littoral floras. Although it appears likely that C. extensa has only recently colonised the site, we consider this discovery to be of significant biogeographical importance.  相似文献   
193.
Although the role of arachidonic acid (AA) in the regulation of steroidogenesis is well documented, the mechanism for AA release is not clear. Therefore, the aim of this study was to characterize the role of an acyl-CoA thioesterase (ARTISt) and an acyl-CoA synthetase as members of an alternative pathway in the regulation of the intracellular levels of AA in steroidogenesis. Purified recombinant ARTISt releases AA from arachidonoyl-CoA (AA-CoA) with a Km of 2 micro m. Antibodies raised against recombinant acyl-CoA thioesterase recognize the endogenous protein in both adrenal tissue and Y1 adrenal tumor cells by immunohistochemistry and immunocytochemistry and Western blot. Stimulation of Y1 cells with ACTH significantly stimulated endogenous mitochondrial thioesterases activity (1.8-fold). Nordihydroguaiaretic acid (NDGA), an inhibitor of AA release known to affect steroidogenesis, affects the in vitro activity of recombinant ARTISt and also the endogenous mitochondrial acyl-CoA thioesterases. ACTH-stimulated steroid synthesis in Y1 cells was significantly inhibited by a synergistic effect of NDGA and triacsin C an inhibitor of the AA-CoA synthetase. The apparent IC50 for NDGA was reduced from 50 micro m to 25, 7.5 and 4.5 micro m in the presence of 0.1, 0.5 and 2 micro m triacsin C, respectively. Our results strongly support the existence of a new pathway of AA release that operates in the regulation of steroid synthesis in adrenal cells.  相似文献   
194.
Phytochemicals and naturally derived compounds, such as plant extracts and bee products, are regarded as complementary and alternative medicines for the treatment of skin wounds, due to their antibacterial, anti-inflammatory, and antioxidant properties. In recent years, it has been shown that dressings impregnated with honey (particularly Manuka honey) are effective for the topical treatment of wounds and burns, and some of them are currently used in clinics. This has stimulated the development of more advanced dressings based on polymeric nanofibres that can release honey and other bee products (like propolis) to promote wound healing. In this review, the current literature on the electrospinning of honey and propolis is analyzed and the effectiveness of the resulting dressings to inhibit bacterial growth and stimulate cellular proliferation and tissue repair is discussed.  相似文献   
195.
Seeds of four lettuce (Lactuca sativa L.) varieties (Romaine, Augusta, Vista and Verte) differing in their salt sensitivity were sown at 0 (Control), 50, 100 and 150 mM NaCl. The final germination percentage decreased with the increasing salinity and was annulated at the highest salt concentration in Vista and Verte, the most sensitive varieties. However, in the less sensitive ones, Romaine and Augusta, it was slightly modified at 50 and 100 mM NaCl and then decreased by 50% compared with the control, at 150 mM. The effects of NaCl 100 mM on seedling growth, phytase activities, phytate and inorganic phosphorus contents were studied in Romaine and Vista showing different behaviours towards salinity. Radicle and hypocotyl length and fresh and dry weights were reduced by salt treatment in both varieties. In addition, radicle phytase activity exhibited an increase in Romaine (less sensitive) and a decrease in Vista (more sensitive). In hypocotyl, this activity showed no difference with the control in the two varieties. However, in cotyledons, and during early hours after germination, salinity decreased phytase activity in both varieties whereas in the later hours (72–96 h) this activity reached the value of the control in Romaine. The enhancement of phytase activity was concomitant with an increase in orthophosphate content and a decrease in phytate reserve. These results suggest that salt presence in the medium delays Pi remobilization from phytate stock, but stimulates assimilation of phosphorus more than its accumulation in the organs of the two lettuce varieties.  相似文献   
196.
MEN 11300, MEN 11301, and MEN 11303 are three recombinant human hybrid proteins that, as has recently been described, induce in vitro erythroid differentiation. This article provides data on their pharmacokinetic and immunogenic behavior after repeated iv administration to cynomolgus monkeys at 0.8 or 1.6 μg/kg doses. Pharmacokinetic data, obtained after the first administration, showed that the half-life (t 1/2) and clearance (CL) values are dose dependent, with no significant differences among the three hybrid proteins. After the tenth administration, MEN 11300 and MEN 11301, both at high and low dose, and MEN 11303 at high dose were undetectable in plasma, whereas MEN 11303 at the lower dose showed no alteration in its pharmacokinetic profile. Immunologic analyses of plasma provided an explanation for this different pharmacokinetic behavior. In fact, plasma samples from animals treated repeatedly with MEN 11300 and MEN 11301 showed specific antibody formation in response to both the high- and the low-dose regimens. These antibodies exerted in vitro a strong neutralizing activity of the hybrid proteins, with a predominant specificity for the erythropoietin (EPO) portion. By contrast, MEN 11303 at the lower dose did not induce a detectable antibody response whereas the antibodies observed on the high-dose regimen did not exert neutralizing activity against the hybrid proteins nor against granulocyte-macrophage colony-stimulating factor (GM-CSF) or EPO. Hematologic parameters were not affected by the treatments, thus indicating that the anti-EPO neutralizing antibody response does not cross react with the endogenous monkey cytokine. The overall immunogenicity data suggest that among the three fusion proteins, MEN 11303 could have a lower immunogenic potential.  相似文献   
197.
Hypertrophic cardiomyopathy (HCM) is one of the most common inherited cardiomyopathy. The identification of patients with HCM is sometimes still a challenge. Moreover, the pathophysiology of the disease is complex because of left ventricular hyper-contractile state, diastolic dysfunction, ischemia and obstruction which can be coexistent in the same patient. In this review, we discuss the current and emerging echocardiographic methodology that can help physicians in the correct diagnostic and pathophysiological assessment of patients with HCM.  相似文献   
198.
M. C. Mele  E. Meucci 《Amino acids》1996,11(1):99-104
Summary The oxidative status of plasma proteins after incubation with elevated homocysteine levels has been examined in the presence and absence of transition metal ions. 200µM homocysteine alone does not provoke any loss of plasma thiols groups, but their oxidation significantly enhances as copper concentration increases. No plasma proteins carbonyl groups enhancement has been concurrently found.The physiological relevance of the study is discussed in relationship with the metal-catalyzed oxidation system increment connected with age and nutritional deficiences.  相似文献   
199.
Dr. E. Meucci  M. C. Mele 《Amino acids》1997,12(3-4):373-377
Summary Amino acids antioxidant capacity has been investigated and compared with the chain-breaking antioxidant activity of known compounds as ascorbic acid and Trolox. Basic and acidic amino acids and most of neutral ones showed no antioxidant capacity. On the contrary, tryptophan, tyrosine, cysteine and homocysteine showed antioxidant ability at concentrations which are within the usually reported physiological ranges.These findings are discussed in connection with the antioxidant capacity ascribed to plasma proteins, as human serum albumin.  相似文献   
200.
Inland saline habitats of the Pannonian Lowland exhibit a specific variety of grasslands determined by a soil salinity gradient. Changes in the hydrological regime and absence of management have resulted in heavy degradation of the vegetation. The impact of topsoil removal on salt steppes was tested by a 3-year small-scale manipulated experiment in SW Slovakia (Kamenínske Slanisko Nature Reserve). Topsoil was removed in three contrasting types of vegetation with different soil salinities, i.e. in different stages of habitat degradation. Data were analysed by multi-way ANOVA and by multivariate methods. Species richness decreased and the proportion of halophytes increased significantly in the two types with the highest soil salinity; however, the total number of halophytes was not influenced by soil removal. The treatment caused inhibition of secondary succession on the plots with the highest salinity. The effect of the soil removal was only short-term in the vegetation with moderate salinity and on heavily degraded and desalinized types it even stimulated further recruitment of ruderal species. Topsoil removal has only limited potential for the restoration of Pannonian salt steppes. It should be applied only in slightly degraded vegetation, where salt accumulation is still present and target species propagules are available.  相似文献   
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