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991.
992.
Y. Ros 《Human genetics》1968,6(2):110-117
Résumé 33 caryotypes masculins et 17 caryotypes féminins ont été étudiés quant à la distribution de chromosomes des groupes A, B et G dans les mitoses au stade métaphase de la division cellulaire.
Ce travail a été subventionné par le Fonds de la recherche médicale 相似文献
Distribution of human chromosomes [1 and 3 (groupe A), 4 and 5 (group B) and 21 and 22 (group G) + the Y chromosome] in metaphase figures of leucocyte division
Summary The object of this paper is to study the distribution of chromosomes in the metaphase figures of human leucocytes cultures. We studied, in the group A, the chromosomes 1 and 3, easily recognisable; in the group B: the chromosomes 4 and 5 and in the group G: the chromosomes 21, 22 and the sex chromosome Y.The method we used consits in calculating the real distance of the centomer of a chromosome to the center of the figure.We compared one distribution to the other and we submitted our results to some statistical tests.It appears clearly that chromosomes are not randomly distributed in metaphase figures of human leucocytes.
Ce travail a été subventionné par le Fonds de la recherche médicale 相似文献
993.
A fourth observation of haemoglobin Stanleyville II has been made. The affected person was a 17-year-old female from the north-eastern area of the Congo Republic, which is entirely inhabited by Nilotes. The amino-acid substitution was found to be a replacement of the asparagine residue by one of lysine in the 78th position of the 141 of the α-chain. 相似文献
994.
Double immunoglobulin production in cloned somatic cell hybrids between two human lymphoid cell lines. 总被引:1,自引:0,他引:1
Several clones of independently established somatic cell hybrids between two human lymphoid cell lines, Raji and Namalwa, were examined for surface immunoglobulin expression. Double-antibody radioimmunoassays were established for kappa and lambda light chains. Immunoglobulins were detergent-extrated by Triton X-100 and quantified by radioimmunoassay. The Raji parent expressed small amounts of kappa chains on its surface, and the Namalwa parent a 10 fold greater amount of lambda chains. We show that the majority of the hybrid clones co-express both parental phenotypes. 相似文献
995.
Diversity dynamics among bivalves during the Triassic and Early Jurassic provides the opportunity to analyse the recovery patterns after two mass extinctions: Permian/Triassic and Triassic/Jurassic (T/J). The results presented here are based on a newly compiled worldwide genus-level database and are contrasted to the main morphological characters of the different taxonomical (orders and their constituent families and genera) and ecological groups. Many of such morphological characters are innovations appearing during the time span considered. Diversity and evolutionary rates were assessed and compared between these groups. During the Early Triassic there was a slow recovery, dominated by epifaunal taxa, the order Pectinida being the most diverse. The major post-Permian radiation took place during the Anisian, with several morphological and ecological innovations appearing and/or diversifying. The Late Triassic was a time of great diversification and ecological specialisation. Although the T/J was a true mass extinction for bivalves, it was not indiscriminate as its impact was stronger on specialised orders and not all ecological categories were equally affected. Recovery during earliest Jurassic was fast, confirming the high-evolutionary resilience of bivalve molluscs, except for groups with thick shells and tropical distribution, probably because of a biocalcification crisis. 相似文献
996.
Exopolymers have been associated with the initial adhesion of bacteria, which is the primary step for biofilm formation. Moreover, the polymeric matrix of biofilms has a considerable influence on some of the most important physical and physiological properties of biofilms. The role of extracellular polymers in biofilm formation was studied using three mutants of Sphingomonas paucimobilis with increasing capabilities for exopolymer production. The physical, biochemical and physiological properties of three different layers of each biofilm were determined. The layers were detached by submitting the biofilm to increasing shear stress. The results revealed that the presence of exopolymers in the growth medium was essential for biofilm formation. The mutant producing the highest amount of exopolymer formed very thick biofilms, while the biofilms formed by the medium exopolymer producer were on average 8 times thinner. The lowest exopolymer producer did not form biofilm. In both types of biofilms, exopolymer density increased with depth, although this tendency was more significant in thinner biofilms. Cell distribution was also more heterogeneous in thinner biofilms, exhibiting a greater accumulation of cells in the inner layers. The thicker biofilms had very low activity in the inner layer. This was related to a high accumulation of proteins and DNA in this layer due to cell lysis and hydrolytic activity. Activity in the thin biofilm was constant throughout its depth, suggesting that there was no nutrient limitation. The production of exopolymers by each cell was constant throughout the depth of the biofilms, although it was greater in the case of the higher producer. 相似文献
997.
Zoubir El‐Hachemi Oriol Arteaga Adolf Canillas Joaquim Crusats Alessandro Sorrenti Sabino Veintemillas‐Verdaguer Josep M. Ribo 《Chirality》2013,25(7):393-399
Experimental results show that benzil (1,2‐diphenyl‐1,2‐ethanedione), an achiral compound that crystallizes as a racemic conglomerate, yields by solidification polycrystalline scalemic mixtures of high enantiomeric excesses. These results are related to those previously reported in this type of compounds on deracemizations of racemic mixtures of crystal enantiomorphs obtained by wet grinding. However, the present results strongly suggest that these experiments cannot be explained without taking into account chiral recognition interactions at the level of precritical clusters. The conditions that would define a general thermodynamic scenario for such deracemizations are discussed. Chirality 25:393–399, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
998.
Manuel A. Vargas‐Ortiz Rodolfo Quintana‐Castro Rosa M. Oliart‐Ros Javier De la Cruz‐Medina José A. Ramírez de León Hugo S. Garcia 《Archives of insect biochemistry and physiology》2013,82(4):196-212
The Mexican fruit fly (Anastrepha ludens) is responsible for losses of up to 25% of crops such as mango and citrus fruits in Central America and México. The larval life cycle of A. ludens comprises three stages with a duration ranging from 3 to 8 days. Because of the damage caused by A. ludens, several methods of control have been studied and implemented. High hydrostatic pressures (HHP) are currently applied to foods and it is now proposed to be employed to inactivate eggs and larvae of A. ludens. Originally HHP was designed to inactivate microorganisms, since it exerts marked effects on cell morphology, and can affect enzymatic reactions and genetic mechanisms of microbial cells, with no major changes altering the sensory or nutritional quality of the foodstuff. In this study, A. ludens in two larval stages (5‐ and 8‐day‐old) were subjected to HHP treatments. The biochemical response of the larvae of A. ludens was dependent on their stage of development. The third larval stage (L3) developed a better protection mechanism based on the synthesis of stress proteins or heat‐shock proteins (HSPs) and the enzyme trehalose‐6‐phosphate synthase, which are linked and possibly act together to achieve greater survivability to stress caused by hydrostatic pressure. 相似文献
999.
Milton Camplesi Júnior Adriano de Moraes Arantes Hildene Meneses Silva Carolina Rodrigues Costa Maria do Rosário Rodrigues Silva 《Mycopathologia》2013,176(5-6):417-421
Changes in the spectrum of clinically important fungal infection have been observed in recent years. Acremonium species has been responsible for eumycotic mycetomas but has also been increasingly implicated in systemic fungal diseases. A case of Acremonium kiliense fungemia with proven involvement of the lungs in an allogeneic hematopoietic stem cell patient is reported. A high-resolution computed tomography scan of the lungs showed nodules in both lungs. Multiple cultures of blood demonstrated narrow septate hyphae, cylindrical conidia, and solitary tapering phialides and microconidia that remained grouped in slimy heads. The isolate was identified as A. kiliense based on its morphological characteristics and DNA sequence analysis. Susceptibility testing of the clinical isolate was performed to four antifungal agents. Amphotericin B, fluconazole and itraconazole were found to be inactive in vitro against the isolate; however, it was found to be sensitive to voriconazole. This last drug was indicated, and a high-resolution computed tomography scan of the lungs was normal after 10 days. One year later, the patient was free of symptoms and her blood culture was negative for fungi. Thus, voriconazole was effective in treatment for life-threatening A. kiliense infections. In this work, we performed an overview of worldwide clinical infections caused by A. kiliense. 相似文献
1000.
Luis Izquierdo Alexandre Ferreira Marques Montserrat Gállego Sílvia Sanz Sílvia Tebar Cristina Riera Lloren? Quintó Edelweiss Aldasoro Igor C Almeida Joaquim Gascon 《Memórias do Instituto Oswaldo Cruz》2013,108(7):928-931
The disappearance of lytic, protective antibodies (Abs) from the serum of patients with Chagas disease is accepted as a reliable indicator of parasitological cure. The efficiency of a chemiluminescent enzyme-linked immunosorbent assay based on a purified, trypomastigote-derived glycosylphosphatidylinositol-anchored mucin antigen for the serologic detection of lytic Abs against Trypanosoma cruzi was evaluated in a nonendemic setting using a panel of 92 positive and 58 negative human sera. The technique proved to be highly sensitive {100%; 95% confidence interval (CI) = 96-100} and specific (98.3%; 95% CI = 90.7-99.7), with a kappa score of 0.99. Therefore, this assay can be used to detect active T. cruzi infection and to monitor trypanosomicidal treatment. 相似文献