全文获取类型
收费全文 | 92篇 |
免费 | 7篇 |
出版年
2021年 | 1篇 |
2017年 | 4篇 |
2016年 | 2篇 |
2015年 | 5篇 |
2014年 | 7篇 |
2013年 | 2篇 |
2012年 | 4篇 |
2011年 | 3篇 |
2010年 | 9篇 |
2009年 | 7篇 |
2008年 | 5篇 |
2007年 | 2篇 |
2006年 | 5篇 |
2005年 | 3篇 |
2004年 | 3篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 1篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1977年 | 2篇 |
1962年 | 1篇 |
1955年 | 1篇 |
1952年 | 1篇 |
1948年 | 1篇 |
1947年 | 1篇 |
排序方式: 共有99条查询结果,搜索用时 312 毫秒
31.
Ferry Cornelissen Adriana MC Mus Patrick S Asmawidjaja Jan Piet van Hamburg Joel Tocker Erik Lubberts 《Arthritis research & therapy》2009,11(6):R194
Introduction
Interleukin (IL)-23 is essential for the development of various experimental autoimmune models. However, the role of IL-23 in non-autoimmune experimental arthritis remains unclear. Here, we examined the role of IL-23 in the non-autoimmune antigen-induced arthritis (AIA) model. In addition, the regulatory potential of IL-23 in IL-17A and retinoic acid-related orphan receptor gamma t (RORγt) expression in CD4+ and TCRγδ+ T cells was evaluated systemically as well as at the site of inflammation. 相似文献32.
A genome survey of Moniliophthora perniciosa gives new insights into Witches' Broom Disease of cacao
Jorge MC Mondego Marcelo F Carazzolle Gustavo GL Costa Eduardo F Formighieri Lucas P Parizzi Johana Rincones Carolina Cotomacci Dirce M Carraro Anderson F Cunha Helaine Carrer Ramon O Vidal Raíssa C Estrela Odalys García Daniela PT Thomazella Bruno V de Oliveira Acássia BL Pires Carolina S Maria Rio Marcos Renato R Araújo Marcos H de Moraes Luis AB Castro Karina P Gramacho Marilda S Gonçalves José P Moura Neto Aristóteles Góes Neto Luciana V Barbosa Mark J Guiltinan Bryan A Bailey Lyndel W Meinhardt Julio CM Cascardo Gonçalo AG Pereira 《BMC genomics》2008,9(1):1-25
33.
GSH appears to be essential for proper development of the root nodules during the symbiotic association of legume-rhizobia in which the entry of rhizobia involves the formation of infection threads. In the particular case of peanut-rhizobia symbiosis, the entry of rhizobia occurs by the mechanism of infection called 'crack entry', i.e. entry at the point of emergence of lateral roots. We have previously shown the role of GSH content of Bradyrhizobium sp. SEMIA 6144 during the symbiotic association with peanut using a GSH-deficient mutant obtained by disruption of the gshA gene, encoding gamma-glutamylcysteine synthetase (gamma-GCS), which was able to induce nodules in peanut roots without alterations in the symbiotic phenotype. To investigate the role of the peanut GSH content in the symbiosis, the compound L-buthionine-sulfoximine (BSO), a specific inhibitor of gamma-GCS in plants, was used. There were no differences in the plant growth and the typical anatomic structure of the peanut roots when the plants grew in the Fahraeus medium either in presence or in absence of 0.1 mM BSO. However, the GSH content was reduced by 51% after treatment with BSO. The BSO-treated plants inoculated with wild-type or mutant strains of Bradyrhizobium sp. showed a significant reduction in the number and dry weight of nodules, suggesting that GSH content could play an important role in the nodulation process of root peanut with Bradyrhizobium sp. 相似文献
34.
35.
We compared histochemical and immunohistochemical staining as well as fluorochrome labeling in murine bone specimens that were fixed with 10% neutral buffered formalin to those fixed with HistoChoice®. We showed that sections from undecalcified tibiae fixed for 4 h in HistoChoice® resulted in enhanced toluidine blue and Von Kossa histochemical staining compared to formalin fixation. HistoChoice® produced comparable or improved staining for alkaline phosphatase. Acid phosphatase localization was better in formalin fixed specimens, but osteoclasts were visuralized more easily in HistoChoice® fixed specimens. As expected, immunohistochemical labeling was antibody dependent; some antibodies labeled better in HistoChoice® fixed specimens while others were better in formalin fixed specimens. Toluidine blue, Von Kossa, and alkaline phosphatase staining of sections fixed for 12 h produced sections that were similar to 4 h fixed sections. Fixation for 12 h preserved acid phosphatase activity better. Increasing fixation to 12 h affected immunolocalization differentially. Bone sialoprotein labeling in HistoChoice® fixed specimens was comparable to formalin fixed samples. On the other hand, after 12 h formalin fixation, osteocalcin labeling was comparable to HistoChoice®. For most histochemical applications, fixing murine bone specimens for 4 h with HistoChoice® yielded superior staining compared to formalin fixation. If immunohistochemical localization is desired, however, individual antibodies must be tested to determine which fixation process retains antigenicity better. In addition, there was no detectable difference in the intensity of fluorochrome labeling using either fixative. Finally, fixation duration did not alter the intensity of labeling. 相似文献
36.
JP Herv s J. Martí -Clú a A. Mu oz-Garcí a MC Santa-Cruz 《Biotechnic & histochemistry》2002,77(1):27-35
We have optimised an indirect immunoperoxidase technique demonstrating bromodeoxyuridine (BrdU) incorporation into dividing cells for cerebellar tissue sections of four-day-old rats injected with this marker. This permits confident identification of granule-cell precursors engaged in DNA synthesis in the external granular layer of the developing cerebellum. Preservation of BrdU immunoreactivity is attained using methanol/acetic acid fixation and different pretreatments before immunostaining, while unlabeled nuclei can be recognized clearly after Feulgen or hematoxylin counterstaining. We established conditions to ensure satisfactory BrdU uptake without affecting cell-cycle progression during the postlabeling time period. The dose of BrdU employed provides saturation S-phase labeling from at least 1 h after BrdU delivery. Various kinetic parameters and phase durations have been determined in experiments involving a single injection or cumulative labeling sequences, and the cycle time was calculated based on two models of generative behavior: steady-state and exponential growth. The working hypothesis of steadystate kinetics can be adopted successfully if the existence of neuroblasts with different proliferation rates is taken into account. 相似文献
37.
38.
The respiratory sensation and some routine cardiorespiratory parameters were studied on native Highlanders from the Argentine
Andes and on Lowlanders from Europe, already tested during previous high altitude expeditions. The tests were performed at
various altitude levels from 2688m e.i., the village altitude for Highlanders, to 5600m during an expedition to Mt. Aconcagua
(6990m). At rest, the perception of 4 external inspiratory resistive loads (ranged between 2.5 and 13 cm.H2O.L-1.s) can allow
us to fix by discrimination the sensitivity index P(A) independently of response bias (B) according to Sensory Decision Theory
(SDT). The Andean highlanders did not experience the respiratory sensation at the same limits as the European lowlanders well
adaptated to high altitude. At higher altitudes than their village altitude, their respiratory sensation presented a lower
threshold of perception and a weaker discrimination which might be partly explained by the evolution of some parameters of
their cardio-respiratory function when altitude increased. Indeed, in response to high altitude hypoxia (5600m), they increased
their respiratory frequency and not their minuteventilation or mouth pressure. This chosen ventilatory pattern was opposite
to the one chosen by the Lowlanders and did not allow for sufficient adaptation to a more important altitude hypoxia than
that of their village altitude. In conclusion, the Andean highlanders wellbeing adapted to their village altitude, exhibited
a difficult acclimatization to higher altitudes which might be due to the characteristics of their respiratory sensation.
These results might explain their weak physical performances during ascent to the Mt. Aconcagua summit in spite of special
training. 相似文献
39.
Variant forms of a group I intron in nuclear small-subunit rRNA genes of the marine red alga Porphyra spiralis var. amplifolia 总被引:3,自引:0,他引:3
A group IC1 intron occurs in nuclear small-subunit (18S) ribosomal RNA (SSU
rRNA) genes of the marine red alga Porphyra spiralis var. amplifolia. This
intron occurs at the same position as the self- splicing group IC1 introns
in nuclear SSU rDNAs of the fungus Pneumocystis carinii and in the green
alga Chlorella ellipsoidea and shares sequence identity with the
Pneumocystis carinii intron in domains L1, P1, P2, and L2, outside the
conserved core. Three size variants, differing in amount of sequence in L1,
exist and are differentially distributed in geographically distinct
populations. Preliminary data suggest that the largest variant can
self-splice in vitro. Short open reading frames are present but do not
correspond to known genes. Repeated nucleotide motifs, reminiscent of
duplicated target sites of transposons or Alu elements, are associated with
the intron and with one of the variant forms of L1. Insertions are present
in nuclear SSU rDNAs of several other Porphyra species and of the red alga
Bangia atropurpurea; insertionless rDNA variants also occur in several
Porphyra species. Our observations are most readily explained by intron
mobility, although it remains unclear how transfer could have been mediated
between genomes of organisms as ecologically diverse as marine red algae,
freshwater green algae, and a mammalian-pathogenic fungus.
相似文献
40.
Dormancy in Peach (Prunus persica L.) Flower Buds : I. Floral Morphogenesis and Endogenous Gibberellins at the End of the Dormancy Period
下载免费PDF全文
![点击此处可从《Plant physiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Luna V Lorenzo E Reinoso H Tordable MC Abdala G Pharis RP Bottini R 《Plant physiology》1990,93(1):20-25
Flower buds of peach (Prunus persica L.) trees, cv Novedad de Cordoba (Argentina), were collected near the end of the dormant period and immediately before anthesis. After removal of scale leaves, morphological observations of representative buds, made on transverse and longitudinal microtome sections, showed that all verticils making up the flower are present in an undifferentiated form during the dormant period (June). Flower buds collected at the end of dormant period (August) showed additional growth and differentiation, at which time formation of two ovules was beginning in the unicarpelar gynoecium. Dehiscence of anthers had not yet occurred 10 days before full bloom, and the ovules were still developing. Free endogenous gibberellin (GA)-like substances were quantified by bioassay (Tan-ginbozu dwarf rice microdrop) after SiO2 partition column chromatography, reversed phase C18-high performance liquid chromatography, and finally Nucleosil [N(CH3)2]high performance liquid chromatography. Bioactive fractions were then subjected to capillary gas chromatography-mass spectrometry-selected ion monitoring (GC-MS-SIM). Gibberellins A1, A3, and A8 were tentatively identified in peach flower buds using GC-SIM and Kovat's retention indices, and relative amounts approximated by GC-SIM (2:8:6 for GA1, GA3, and GA8, respectively). The highest concentration (330 nanograms per gram dry weight) of free GA1/GA3 was found in dormant buds (June) and diminished thereafter. The concentration free of GA1/GA3 did not increase immediately prior to bud break. However, high GA1/GA3 concentrations occurred during stages where rate of growth and cellular differentiation of (mainly fertile) verticils can be influenced. 相似文献