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21.
A convenient large scale purification of the alpha-1 trypsin inhibitor from human plasma was achieved by conventional salting out and column chromatography methods. The pure inhibitor complexes 0.68 μgs of bovine trypsin per ug inhibitor, and 0.60 μgs human trypsin per μg inhibitor. The inhibitor is homogeneous by equilibrium chromatography, disc electrophoresis, and ultracentrifugation. Conditions for its storage with minimal loss of activity are described. The advantages of the present preparation are higher potency, long-term stability, and large scale. 相似文献
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A novel microtubule-associated protein-2 expressed in oligodendrocytes in multiple sclerosis lesions
Elucidation of the mechanisms involved in the regeneration of oligodendrocytes and remyelination is a central issue in multiple sclerosis (MS) research. We recently identified a novel alternatively spliced, developmentally regulated oligodendrocyte-specific protein designated microtubule-associated protein-2+13 [microtubule-associated protein-2 expressing exon 13 (MAP-2+13)]. MAP-2+13 is expressed in human fetal oligodendrocytes during process extension and myelination but is minimally expressed in normal mature CNS. To test the hypothesis that MAP-2+13 is reexpressed in regenerating oligodendrocytes in MS lesions, we examined the brains of MS patients for the expression of this protein. By immunocytochemistry using a series of monoclonal antibodies specific for MAP-2+13, we determined that MAP-2+13 expression was up-regulated in all 31 lesions from 10 different MS brains. MAP-2+13 was expressed in regenerating oligodendrocytes associated with demyelinated lesions, with the highest counts found in regions of extensive remyelination. By electron microscopy, MAP-2+13 was localized to oligodendrocytes engaged in remyelination, evident by their process extension and association with thinly myelinated (remyelinated) and demyelinated axons. These results suggest a hitherto unsuspected role for this microtubule-associated protein in oligodendrocyte function during development and myelin repair. 相似文献
26.
Lewis RA Kress TL Cote CA Gautreau D Rokop ME Mowry KL 《Mechanisms of development》2004,121(1):101-109
Although it is widely regarded that the targeting of RNA molecules to subcellular destinations depends upon the recognition of cis-elements found within their 3' untranslated regions (UTR), relatively little is known about the specific features of these cis-sequences that underlie their function. Interaction between specific repeated motifs within the 3' UTR and RNA-binding proteins has been proposed as a critical step in the localization of Vg1 RNA to the vegetal pole of Xenopus oocytes. To understand the relative contributions of repeated localization element (LE) sequences, we used comparative functional analysis of Vg1 LEs from two frog species, Xenopus laevis and Xenopus borealis. We show that clusters of repeated VM1 and E2 motifs are required for efficient localization. However, groups of either site alone are not sufficient for localization. In addition, we present evidence that the X. borealis Vg1 LE is recognized by the same set of RNA-binding proteins as the X. laevis Vg1 LE and is capable of productive interactions with the X. laevis transport machinery as it is sufficient to direct vegetal localization in X. laevis oocytes. These results suggest that clustered sets of cis-acting sites within the LE direct vegetal transport through specific interactions with the localization machinery. 相似文献
27.
The pantropical Zingiberaceae is the largest family in the order Zingiberales with 53 genera and over 1200 species. Classifications of the family first proposed in 1889 and refined by others since that time recognize four tribes (Globbeae, Hedychieae, Alpinieae, and Zingibereae) based on morphological features, such as number of locules and placentation in the ovary, development of staminodia, modifications of the fertile anther, and rhizome-shoot-leaf orientation. New phylogenetic analyses based on DNA sequences of the nuclear internal transcribed spacer (ITS) and plastid matK regions suggest that at least some of these morphological traits are homoplasious and three of the tribes are paraphyletic. The African genus Siphonochilus and Bornean genus Tamijia are basal clades. The former Alpinieae and Hedychieae for the most part are monophyletic taxa with the Globbeae and Zingibereae included within the latter. The results of these phylogenetic investigations are used to propose a new classification of the Zingiberaceae that recognizes four subfamilies and four tribes: Siphonochiloideae (Siphonochileae), Tamijioideae (Tamijieae), Alpinioideae (Alpinieae, Riedelieae), and Zingiberoideae (Zingibereae, Globbeae). Morphological features congruent with this classification and the taxonomic status of various monotypic genera are discussed. 相似文献
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Kress W Collmann H Büsse M Halliger-Keller B Mueller CR 《Cytogenetics and cell genetics》2000,91(1-4):134-137
A cohort of 36 unrelated German patients with craniosynostosis syndromes of the Crouzon and Pfeiffer type were analyzed for FGFR mutations. Mutations in FGFR2 were identified in 25 Crouzon and 5 Pfeiffer syndrome patients, whereas no sequence alterations were found in the remaining patients, even after screening of the relevant parts of FGFR1, FGFR3, and TWIST. Mutations in FGFR2 clustered at two critical cysteine residues, 278 and 342, which were involved in 18 of 30 cases (60%). These two mutational hot spots, therefore, are prime targets for an efficient mutation-screening strategy. The spectrum of mutations overlapped the two syndromes and thus reflected the phenotypic similarities observed in both patient groups. In 21 families, the origin of the mutation could be traced by analyzing parents and relatives. Eleven mutations arose de novo, indicating a high mutation rate for FGFR2. In the 10 familial cases, the clinical presentation varied considerably within the pedigree, but both syndromes "bred true," i.e., a Pfeiffer syndrome phenotype was never observed in a Crouzon syndrome family and vice versa. 相似文献
29.
Non-syndromic trigonocephaly is a heterogeneous entity; in most cases the origin is unknown. Rare cases with autosomal dominant and recessive inheritance exist. Here the mutational screening of ten patients in the FGFR1, 2, and 3 genes and the TWIST gene causative of autosomal dominant craniosynostosis syndromes was reported. In one girl an unusual FGFR1 mutation was found. 相似文献
30.
Testing DNA barcodes in closely related species of Curcuma (Zingiberaceae) from Myanmar and China 下载免费PDF全文
The genus Curcuma L. is commonly used as spices, medicines, dyes and ornamentals. Owing to its economic significance and lack of clear‐cut morphological differences between species, this genus is an ideal case for developing DNA barcodes. In this study, four chloroplast DNA regions (matK, rbcL, trnH‐psbA and trnL‐F) and one nuclear region (ITS2) were generated for 44 Curcuma species and five species from closely related genera, represented by 96 samples. PCR amplification success rate, intra‐ and inter‐specific genetic distance variation and the correct identification percentage were taken into account to assess candidate barcode regions. PCR and sequence success rate were high in matK (89.7%), rbcL (100%), trnH‐psbA (100%), trnL‐F (95.7%) and ITS2 (82.6%) regions. The results further showed that four candidate chloroplast barcoding regions (matK, rbcL, trnH‐psbA and trnL‐F) yield no barcode gaps, indicating that the genus Curcuma represents a challenging group for DNA barcoding. The ITS2 region presented large interspecific variation and provided the highest correct identification rates (46.7%) based on BLASTClust method among the five regions. However, the ITS2 only provided 7.9% based on NJ tree method. An increase in discriminatory power needs the development of more variable markers. 相似文献