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1.
Embryogenesis and plant regeneration from anther culture of bamboo (Sinocalamus latiflora (Munro) McClure) 总被引:1,自引:0,他引:1
Embryogenic callus was initiated from bamboo (Sinocalumus satiflora (Munro) McClure) anthers cultured on N6 medium supplemented with 1 mg/l 2,4-D, 1 mg/l BA, 2 g/l charcoal, 0.8% agar (Sigma) and 9% sucrose. Anthers with microspores at miduninucleate to early-binucleate stages showed better rate of response for callus induction. Prolonged culture of these embryogenic calli on the original medium or subculture to an auxin-free medium resulted in embryoid formation and their subsequent germination to form rooted plantlets. Chromosome counts from root-tip cells of anther-derived plant indicated that they were haploid (N=36).Abbreviations N6
Chu et al. (1975)
- MS
Murashige and Skoog (1962)
- 2,4-D
2,4-dichlorophenoxyacetic acid
- NAA
-naphthaleneacetic acid
- BA
6-benzylaminopurine 相似文献
2.
Abstract— Analysis of whole autopsy brain from a patient with fucosidosis (α-fucosidase deficiency) revealed minor storage of H-antigen glycolipid [Fuc (α, 1→2) Gal-GlcNAc-Gal-Glc-Ceramide] and a slightly abnormal ganglioside composition in the form of a two-fold elevation of GM1 and the presence of a fucose-containing glycolipid (a minor component) which co-migrated with GD1a. The major storage materials in fucosidosis brain were an oligosaccharide (Fuc-Gal-GlcNAc-Man[Fuc-Gal-GlcNAc-Man]-ManGlcNAc) and a disaccharide [Fuc(α, 1→6)-GlcNAc] in the approximate ratio of 5:1. Lesser amounts of a related oligosaccharide (Gal-GlcNAc-Man[Gal-GlcNAc-Man]-Man-GlcNAc) were isolated from the brain of patients with GM1-gangliosidosis (Types I and II) where the major storage material is known to be GM1-ganglioside (Gal (β, 1→3)GalNAc(β, 1→4) [NeuNAcf(α, 2→3) Gal(β, 1→4)Glc-Ceramide). Similarly, a related oligosaccharide (GlcNAc-Man [GlcNAc-Man]-Man-GlcNAc) was isolated from the brain of a patient with a total deficiency of N-acetyl-β-d -hexosaminidase (Sandhoff variant of GM2-gangliosidosis) where the major storage products are known to be GM2-ganglioside (GalNAc (β 1→4) [NeuNAc (α, 2→3)Gal(β, 1→4)Glc-Ceramine) and its asialo derivative. These studies indicate that glycoproteins containing at least 2 mol of l -fucose per oligosaccharide unit are normally catabolized in human brain. Further, it appears that such glycoproteins are initially catabolized by an endo-N-acetylglucosaminidase to release an oligosaccharide which is then degraded by the sequential action of exo-glycosidases. 相似文献
3.
Gaelle Rossignol Annabelle Merieau Josette Guerillon Wilfried Veron Olivier Lesouhaitier Marc GJ Feuilloley Nicole Orange 《BMC microbiology》2008,8(1):189
Background
Pseudomonas fluorescens is a ubiquitous Gram-negative bacterium frequently encountered in hospitals as a contaminant of injectable material and surfaces. This psychrotrophic bacterium, commonly described as unable to grow at temperatures above 32°C, is now considered non pathogenic. We studied a recently identified clinical strain of P. fluorescens biovar I, MFN1032, which is considered to cause human lung infection and can grow at 37°C in laboratory conditions. 相似文献4.
The expression pattern of zebrafish hoxa1a mRNA during embryonic development was studied. Herein, we show that hoxa1a mRNA is expressed in the ventral region of both the midbrain and anterior hindbrain during the developmental period from the pharyngula to the protruding-mouth stages via whole-mount in situ hybridization. Furthermore, double-labeling with anti-zHu antibody confirms that the zebrafish hoxa1a gene is expressed in neuronal cells. The observed temporal and spatial distributions of zebrafish hoxa1a mRNA differ greatly from the expression patterns of zebrafish hoxb1a and hoxb1b paralagous genes. In addition, in embryos injected with mouse ihh mRNA, hoxa1a-expressing cells increase in number with a dorsalized expression pattern in the midbrain. 相似文献
5.
Yin-Kai Chen Hsin-An Hou Jih-Luh Tang Jie-Yang Jhuang Yan-Jun Lai Ming-Cheng Lee Yuan-Yeh Kuo Wen-Chien Chou Chieh-Yu Liu Chung-Wu Lin Shih-Sung Chuang Chien-Yuan Chen Mei-Hsuan Tseng Chi-Fei Huang Ying-Chieh Chiang Fen-Yu Lee Ming-Chih Liu Chia-Wen Liu Ming Yao Shang-Yi Huang Bor-Sheng Ko Szu-Chun Hsu Shang-Ju Wu Woei Tsay Yao-Chang Chen Hwei-Fang Tien 《PloS one》2015,10(3)
Background
Robo4 is involved in hematopoietic stem/progenitor cell homeostasis and essential for tumor angiogenesis. Expression of Robo4 was recently found in solid tumors and leukemia stem cells. However, the clinical implications of Robo4 expression in patients with acute myeloid leukemia (AML) remain unclear.Methods
We investigated the clinical and prognostic relevance of mRNA expression of Robo4 in bone marrow (BM) mononuclear cells from 218 adult patients with de novo AML. We also performed immunohistochemical staining to assess the Robo4 protein expression in the BM biopsy specimens from 30 selected AML patients in the cohort.Results
Higher Robo4 expression was closely associated with lower white blood cell counts, expression of HLA-DR, CD13, CD34 and CD56 on leukemia cells, t(8;21) and ASXL1 mutation, but negatively correlated with t(15;17) and CEBPA mutation. Compared to patients with lower Robo4 expression, those with higher expression had significantly shorter disease-free survival (DFS) and overall survival (OS). This result was confirmed in an independent validation cohort. Furthermore, multivariate analyses showed that higher Robo4 expression was an independent poor prognostic factor for DFS and OS in total cohort and patients with intermediate-risk cytogenetics, irrespective of age, WBC count, karyotype, and mutation status of NPM1/FLT3-ITD, and CEBPA.Conclusions
BM Robo4 expression can serve as a new biomarker to predict clinical outcomes in AML patients and Robo4 may serve as a potential therapeutic target in patients with higher Robo4 expression. 相似文献6.
AB Chang NC Cox J Purcell JM Marchant PJ Lewindon GJ Cleghorn LC Ee GD Withers MK Patrick J Faoagali 《Respiratory research》2005,6(1):1-5
Background and methods
Human metapneumovirus (hMPV) is a recently discovered respiratory virus associated with bronchiolitis, pneumonia, croup and exacerbations of asthma. Since respiratory viruses are frequently detected in patients with acute exacerbations of COPD (AE-COPD) it was our aim to investigate the frequency of hMPV detection in a prospective cohort of hospitalized patients with AE-COPD compared to patients with stable COPD and to smokers without by means of quantitative real-time RT-PCR.Results
We analysed nasal lavage and induced sputum of 130 patients with AE-COPD, 65 patients with stable COPD and 34 smokers without COPD. HMPV was detected in 3/130 (2.3%) AE-COPD patients with a mean of 6.5 × 105 viral copies/ml in nasal lavage and 1.88 × 105 viral copies/ml in induced sputum. It was not found in patients with stable COPD or smokers without COPD.Conclusion
HMPV is only found in a very small number of patients with AE-COPD. However it should be considered as a further possible viral trigger of AE-COPD because asymptomatic carriage is unlikely. 相似文献7.
Glucocorticoids or the glucocorticoid analog dexamethasone (DEX) enhances the differentiation of preadipocytes in the presence of insulin and influences preadipocyte proliferation. The purpose of the present study was to determine if DEX can induce the recruitment of preadipocytes. Using monoclonal antibodies for complement-mediated cytotoxicity, preadipocytes were removed from porcine stromal vascular (S-V) cell cultures. Our experiments demonstrated for the first time that after removal of preadipocytes by cytotoxicity, preadipocytes or fat cells could be induced by DEX or DEX plus insulin but not by insulin alone. However, many more fat cells were induced (258 ± 15/unit area) when DEX was added with fetal bovine serum (FBS) followed with insulin treatment, compared to DEX with insulin (21.3 ± 5.1/ unit area) after removal of preadipocytes. Immunocyto-chemistry with AD-3, a preadipocyte marker, showed that DEX with FBS for 3 days after seeding (i.e., the proliferation phase) produced many more preadipocytes (AD-3 positive, 223 ± 45/unit area) than FBS alone (10.5 ± 1.4/unit area). Bromodeoxyuridine (BrdU) incorporation assays demonstrated that the efficiency of DEX with FBS (i.e., during proliferation) was mitosis dependent. Accordingly, we conclude that: porcine S-V cultures contain preadipocytes at different stages of differentiation and that DEX induced early preadipocyte differentiation depends on mitosis. 相似文献
8.
Liu GY Liao YF Hsu PC Chang WH Hsieh MC Lin CY Hour TC Kao MC Tsay GJ Hung HC 《Apoptosis : an international journal on programmed cell death》2006,11(10):1773-1788
Antizymes delicately regulate ornithine decarboxylase (ODC) enzyme activity and polyamine transportation. One member of the
family, antizyme-1, plays vital roles in molecular and cellular functions, including developmental regulation, cell cycle,
proliferation, cell death, differentiation and tumorigenesis. However, the question of how does it participate in the cell
apoptotic mechanism is still unsolved. To elucidate the contribution of human antizyme-1 in haematopoietic cell death, we
examine whether inducible overexpression of antizyme enhances apoptotic cell death. Antizyme reduced the viability in a dose-
and time-dependent manner of human leukemia HL-60 cells, acute T leukemia Jurkat cells and mouse macrophage RAW 264.7 cells.
The apoptosis-inducing activities were determined by nuclear condensation, DNA fragmentation, sub-G1 appearance, loss of mitochondrial membrane potential (Δψ
m
), release of mitochondrial cytochrome c into cytoplasm and proteolytic activation of caspase 9 and 3. Following conditional antizyme overexpression, all protein
levels of cyclin-dependent kinases (Cdks) and cyclins are not significantly reduced, except cyclin D, before their entrance
into apoptotic cell death. However, introduced cyclin D1 into Jurkat T tetracycline (Tet)-On cell system still couldn’t rescue
cells from apoptosis. Antizyme doesn’t influence the expression of tumor suppressor p53 and its downstream p21, but it interferes
in the expressions of Bcl-2 family. Inducible antizyme largely enters mitochondria resulting in cytochrome c release from mitochondria to cytosol following Bcl-xL decrease and Bax increase. According to these data, we suggest that
antizyme induces apoptosis mainly through mitochondria-mediated and cell cycle-independent pathway. Furthermore, antizyme
induces apoptosis not only by Bax accumulation reducing the function of the Bcl-2 family, destroying the Δψ
m
, and releasing cytochrome c to cytoplasm but also by the activation of apoptosomal caspase cascade. 相似文献
9.
Rottlerin is a widely selective protein kinase C delta (PKCdelta) inhibitor isolated from Mallotus philippinensis. It shown to be effective against several human tumor cell lines and in potentiating chemotherapy-induced cytotoxcicity. Using the trypan blue exclusion assay, we demonstrated that rottlerin reduced the viability in a dose- and time-dependent manner of human leukemia HL60 cells, human acute T cell leukemia Jurkat cells and mouse macrophage RAW 264.7 cells. Rottlerin caused apoptosis and the apaptotic processing was inhibited by a caspase inhibitor, z-VAD-fmk, in these haematopoietic cells. The apoptosis-inducing activities were determined by nuclear condensation, sub-G1 appearance, DNA fragmentation, loss of mitochondrial membrane potential (Deltapsim), release of mitochondrial cytochrome c into cytoplasm and proteolytic activation of caspase 9 and 3. Expression of PKCdelta and Bcl-2 protein inhibited Deltapsim change and repressed cell death. These studies suggest that the cytotoxic effects of rottlerin through inhibition of PKCdelta cause mitochondrial dysfunction, cytochrome c release from mitochondria into cytoplasm and the activation of caspases' cascade. 相似文献
10.
Structural variation in human apolipoprotein E3 and E4: secondary structure, tertiary structure, and size distribution 下载免费PDF全文
Chou CY Lin YL Huang YC Sheu SY Lin TH Tsay HJ Chang GG Shiao MS 《Biophysical journal》2005,88(1):455-466
Human apolipoprotein E (apoE) is a 299-amino-acid protein with a molecular weight of 34 kDa. The difference between the apoE3 and apoE4 isoforms is a single residue substitution involving a Cys-Arg replacement at residue 112. ApoE4 is positively associated with atherosclerosis and late-onset and sporadic Alzheimer's disease (AD). ApoE4 and its C-terminal truncated fragments have been found in the senile plaques and neurofibrillary tangles in the brain of AD patients. However, detail structural information regarding isoform and domain interaction remains poorly understood. We prepared full-length, N-, and C-terminal truncated apoE3 and apoE4 proteins and studied their structural variation. Sedimentation velocity and continuous size distribution analysis using analytical ultracentrifugation revealed apoE3(72-299) as consisting of a major species with a sedimentation coefficient of 5.9. ApoE4(72-299) showed a wider and more complicated species distribution. Both apoE3 and E4 N-terminal domain (1-191) existed with monomers as the major component together with some tetramer. The oligomerization and aggregation of apoE protein increased when the C-terminal domain (192-271) was incorporated. The structural influence of the C-terminal domain on apoE is to assist self-association with no significant isoform preference. Circular dichroism and fluorescence studies demonstrated that apoE4(72-299) possessed a more alpha-helical structure with more hydrophobic residue exposure. The structural variation of the N-terminal truncated apoE3 and apoE4 protein provides useful information that helps to explain the greater aggregation of the apoE4 isoform and thus has implication for the involvement of apoE4 in AD. 相似文献