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1.
E. Lendaro R. Ippoliti A. Brancaccio A. Bellelli B. Vallone G. Ivaldi G.V. Sciarratta C. Castello S. Tomova M. Brunori G. Amiconi 《生物化学与生物物理学报:疾病的分子基础》1992,1180(1):15-20
Hemoglobin Dallas, an α-chain variant with a substitution of lysine for asparagine at position 97(G4), was found to have increased oxygen affinity () and reduced Bohr effect (about 50%). Addition of allosteric effectors (such as 2,3-diphosphoglycerate, inositol hexakisphosphate and bezafibrate) led to a decrease in oxygen affinity and increase in cooperative energy. Kinetic studies at pH 7.0 and 20°C revealed that (i), the overall rate of oxygen dissociation is 1.4-fold slower than that for HbA and (ii), the carbon monoxide dissociation rate is unaffected. The abnormal properties of this hemoglobin variant can be atttributed to a more ‘relaxed’ T-state. 相似文献
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Mohsen A. F. El-Hazmi Hassan M. Bahakim Arjumand S. Warsy Abdulkarim Al-Momen Abdullah Al-Wazzan Ibrahim Al-Fawwaz Sameer Huraib Mohammad Harakati 《Molecular and cellular biochemistry》1993,124(1):17-22
Sickle cell anaemia (SCA) exhibits significant variations in clinical presentation in different populations for which several genetic factors including SCA-associated -and -thalassaemias, G-6-PD deficiency and elevated Hb F level have been implicated as possible ameliorating factors. Saudi Arabia is unique in that mild and severe forms of the disease occur at a high frequency. We investigated the G/A ratio and Hb F level and correlated these values with the severity of SCA. The results showed that Hb F level varies significantly in both groups of patients with no evident correlation with the mild clinical manifestations. However, G/A ratio correlated significantly with the disease severity where a high ratio was observed in patients with the mild and a low ratio in patients with the severe disease. The results are evaluated and discussed in the light of correlation studies and regression analysis. 相似文献
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We have used [2-13C]d-glucose and carbon-13 nuclear magnetic resonance (NMR) spectroscopy to investigate metabolic fluxes through the major pathways of glucose metabolism in intact human erythrocytes and to determine the interactions among these pathways under conditions that perturb metabolism. Using the method described, we have been able to measure fluxes through the pentose phosphate pathway, phosphofructokinase, the 2,3-diphosphoglycerate bypass, and phosphoglycerate kinase, as well as glucose uptake, concurrently and in a single experiment. We have measured these fluxes in normal human erythrocytes under the following conditions: (1) fully oxygenated; (2) treated with methylene blue; and (3) deoxygenated. This method makes it possible to monitor various metabolic effects of stresses in normal and pathological states. Not only has 13C-NMR spectroscopy proved to be a useful method for measuring in vivo flux through the pentose phosphate pathway, but it has also provided additional information about the cycling of metabolites through the non-oxidative portion of the pentose phosphate pathway. Our evidence from experiments with [1-13C]-, [2-13C]-, and [3-13C]d-glucoses indicates that there is an observable reverse flux of fructose 6-phosphate through the reactions catalyzed by transketolase and transaldolase, even in the presence of a net flux through the pentose phosphate pathway. 相似文献
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六种鼠苹果酸脱氢酶,血浆蛋白质和血红蛋白的变异分析 总被引:3,自引:0,他引:3
本文分析了家鼠属(Rattus)4种鼠和姬鼠属(Apodemus)2种鼠的苹果酸脱氢酶、血浆中β1区和β2区蛋白质、血浆清蛋白、前清蛋白以及红细胞中血红蛋白的变异。结果表明,MDH在进化上是比较保守的,其中MDHm和MDHs2带在各鼠间位于同一泳动线上,仅MDHs1带的泳动速度出现属间和种间的微小差异;血浆中β1区和β2区的蛋白质带、清蛋白带以及前清蛋白带各鼠间出现明显的变异,表现为黑线姬鼠和社鼠在β1区出现2种多态型区带,褐家鼠在β2区也有2种多态型带;各鼠间的血红蛋白变异比较明显,主要表现在区带数和主成分的泳动度显著不同,而且社鼠的Hb出现3种多态型,黄毛鼠出现2种多态型,其余各鼠的Hb皆为单态性。上述16项生化特性按相似和相异进行配对比较,初步表明黄毛鼠与褐家鼠亲缘上比较相近,白腹巨鼠要比其他3种鼠亲缘上更接近于黑线姬鼠,而社鼠与白腹巨鼠之间进化分歧相对地较大。 相似文献
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Mutant hemoglobin stability depends upon location and nature of single point mutation 总被引:1,自引:0,他引:1
The temperature dependence of the rates of heme release from the beta subunits of methemoglobin A and 5 beta mutant methemoglobins has been determined. The rates were largest for two hemoglobins with mutations distal to heme, previously known to be unstable. The other 3 mutants also released heme faster than A. These hemoglobins, with single point mutations at the alpha 1/beta 2 interface, were previously thought to be stable. The low reported yields of the 5 mutant proteins covaries with the relative rates of heme release from the met species. 相似文献
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Evaluation of genetic risks of alkylating agents. III. Alkylation of haemoglobin after metabolic conversion of ethene to ethene oxide in vivo 总被引:3,自引:0,他引:3
L Ehrenberg S Osterman-Golkar D Segerbck K Svensson C J Calleman 《Mutation research》1977,45(2):175-184
Male CBA mice, exposed to air contaminated with [14C] labelled ethene, were able to metabolize this olefine to ethene oxide. The amount of epoxide formed was quantitatively determined from the degree of alkylation of cysteine and histidine in haemoglobin. These hydroxyethylated amino acids were determined by ion-exchange chromatography of the labelled products. In a separate experiment the formation of S-(2-hydroxyethyl) cysteine was verified by gas chromatography--mass spectrometry. In addition this cysteine derivative was determined in urine by thin-layer chromatography. For unknown reasons, uninduced mice varied strongly in the extent to which they converted ethene to epoxide. 相似文献
10.
Jayalakshmi Kumpati 《Biochemical and biophysical research communications》1982,105(2):482-487
To investigate the role of phenylalanine and tryptophane as potential antisickling agents in intact human SS-red blood cells a liposomal transport system was employed to transfer phenyl-alanine or tryptophane into intact SS-red blood cells. Aromatic amino acids and short peptides containing phenylalanine have been demonstrated to increase the minimum gelling concentration and solubility of deoxy-hemoglobin S in aqueous solution. However, these compounds do not cross the red blood cell membrane under usual incubation conditions. Incorporation of phenylalanine or tryptophane into intact SS-red blood cells liposomal transport system markedly inhibited the sickling of deoxy-hemoglobin S. These findings raise the possibility that a nontoxic liposomal transport system which facilitates incorporation of antisickling agents into intact SS-RBC may have significant therapeutic implications in the treatment of sickle cell disease. 相似文献