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31.
Melatonin stimulates the expansion of etiolated lupin cotyledons 总被引:1,自引:0,他引:1
Melatonin (N-acetyl-5-methoxytryptamine) is an indoleamine which is structurally related to tryptophan, serotonin and indole-3-acetic
acid (IAA), among other important substances. Many studies have clearly demonstrated its presence in different plant organs,
including roots, stems, leaves, flowers, fruits and seeds. Since it discovery in plants in 1995, authors have postulated many
physiological roles for melatonin, although research into this molecule in plants is still in its infancy. The data presented
in this study demonstrate that melatonin stimulates the expansion of etiolated cotyledons of lupin (Lupinus albus L.) to a similar extent to that observed for IAA but less than in the case of kinetin. Endogenous melatonin in imbibed cotyledons
has been quantified using a liquid chromatography method with fluorescence detection and capacity of cotyledons to absorb
melatonin has been determined. The observed effect of melatonin on lupin cotyledon expansion can be added to the other effects
demonstrated by our group such as its role as growth promoter and rooting promotor in adventitious and lateral roots. 相似文献
32.
Kappa-chain constant-region gene sequences in genus Rattus: coding regions are diverging more rapidly than noncoding regions 总被引:2,自引:0,他引:2
We have determined the nucleotide sequence of a 1,200-base pair (bp)
genomic fragment that includes the kappa-chain constant-region gene (C
kappa) from two species of native Australian rodents, Rattus leucopus
cooktownensis and Rattus colletti. Comparison of these sequences with each
other and with other rodent C kappa genes shows three surprising features.
First, the coding regions are diverging at a rate severalfold higher than
that of the nearby noncoding regions. Second, replacement changes within
the coding region are accumulating at a rate at least as great as that of
silent changes. Third, most of the amino acid replacements are localized in
one region of the C kappa domain--namely, the carboxy-terminal "bends" in
the alpha-carbon backbone. These three features have previously been
described from comparisons of the two allelic forms of C kappa genes in R.
norvegicus. These data imply the existence of considerable evolutionary
constraints on the noncoding regions (based on as yet undetermined
functions) or powerful positive selection to diversify a portion of the
constant-region domain (whose physiological significance is not known).
These surprising features of C kappa evolution appear to be characteristic
only of closely related C kappa genes, since comparison of rodent with
human sequences shows the expected greater conservation of coding regions,
as well as a predominance of silent nucleotide substitutions within the
coding regions.
相似文献
33.
M B Arnao J L Casas J A del Río M Acosta F García-Cánovas 《Analytical biochemistry》1990,185(2):335-338
A sensitive colorimetric method for naringin estimation using 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) as peroxidase substrate is described. The method is based on the coupling reaction of an ABTS radical cation with an oxidation product of naringin formed by peroxidase. This coupling reaction leads to the formation of a purple-colored compound with a maximum absorption at 560 nm. A molar absorption coefficient at this wavelength was calculated to be 13,286 +/- 200 M-1 cm-1. The lowest amount of naringin that can be detected is 1 nmol. The application of this method to the quantification of naringin in grapefruit tissues is presented. 相似文献
34.
MB Malipatil 《Australian Journal of Entomology》2005,44(2):122-131
Abstract Two new species of Nysius Dallas, N. orarius sp. n. and N. tasmaniensis sp. n. are described from New South Wales and Tasmania (Australia), respectively. A new monotypic genus, Reticulatonysius , with type-species R. queenslandensis sp. n. is described from Queensland, and its systematic relationship with other orsilline genera is discussed. 相似文献
35.
Johanna W. Baars Johanna C. M. Fonk Riekeld J. Scheper B. Mary E. von Blomberg-van der Flier Herman Bril M.D. Paul v. d. Valk Herbert M. Pinedo John Wagstaff MD MB ChB MRCP 《Biotherapy》1992,4(4):289-297
Tumour infiltrating lymphocytes (TIL) were isolated and expanded from biopsy samples of 4 patients with metastatic melanoma. The patients were treated with autologous expanded TIL and continuous or bolus infusion of Interleukin 2 (IL-2) at a dose of 18 × 106 International Units/m2/day for 5 days starting 36–48 hours after administration of cyclophosphamide at a dose of 1 g/m2. The number of TIL infused ranged from 1010 to 5,56 × 1010 cells. Two patients had stable disease (SD) lasting for 2 1/2 and 4 months respectively and they died 24 and 13 months after therapy. One patient died during therapy due to a pseudomonas septicaemia and another patient developed progressive disease (PD). He died 3 months after the start of therapy. The side effects were substantial but most of them were reversible upon cessation of the treatment.The majority of the expanded TIL of all patients were of the CD8+ phenotype. Cutaneous metastases from two patients, removed after treatment with IL-2 and TIL, showed moderate lymphocytic infiltration also mainly of CD8+ T cells.The treatment with IL-2 and TIL is feasible, but further investigations should continue in an attempt to improve the efficacy of the therapy, to reduce toxicity and to diminish the costs and labour of the culture methods. 相似文献
36.
Menhas Saiqa Yang Xijia Hayat Kashif Aftab Tariq Bundschuh Jochen Arnao Marino Bañón Zhou Yuanfei Zhou Pei 《Journal of Plant Growth Regulation》2022,41(3):922-935
Journal of Plant Growth Regulation - Heavy metal pollution is of increasing global concern as it adversely impacts different spheres including pedosphere, hydrosphere, biosphere, and humansphere.... 相似文献
37.
Franc-Christophe Baurens Stéphanie Bocs Mathieu Rouard Takashi Matsumoto Robert NG Miller Marguerite Rodier-Goud Didier MBéguié-A-MBéguié Nabila Yahiaoui 《BMC plant biology》2010,10(1):149
Background
Comparative sequence analysis of complex loci such as resistance gene analog clusters allows estimating the degree of sequence conservation and mechanisms of divergence at the intraspecies level. In banana (Musa sp.), two diploid wild species Musa acuminata (A genome) and Musa balbisiana (B genome) contribute to the polyploid genome of many cultivars. The M. balbisiana species is associated with vigour and tolerance to pests and disease and little is known on the genome structure and haplotype diversity within this species. Here, we compare two genomic sequences of 253 and 223 kb corresponding to two haplotypes of the RGA08 resistance gene analog locus in M. balbisiana "Pisang Klutuk Wulung" (PKW). 相似文献38.
39.
Vibeke Secher Dam Donna MB Boedtkjer Christian Aalkjaer Vladimir Matchkov 《Channels (Austin, Tex.)》2014,8(4):361-369
The presence of Ca2+-activated Cl– currents (ICl(Ca)) in vascular smooth muscle cells (VSMCs) is well established. ICl(Ca) are supposedly important for arterial contraction by linking changes in [Ca2+]i and membrane depolarization. Bestrophins and some members of the TMEM16 protein family were recently associated with ICl(Ca). Two distinct ICl(Ca) are characterized in VSMCs; the cGMP-dependent ICl(Ca) dependent upon bestrophin expression and the ‘classical’ Ca2+-activated Cl– current, which is bestrophin-independent. Interestingly, TMEM16A is essential for both the cGMP-dependent and the classical ICl(Ca). Furthermore, TMEM16A has a role in arterial contraction while bestrophins do not. TMEM16A’s role in the contractile response cannot be explained however only by a simple suppression of the depolarization by Cl– channels. It is suggested that TMEM16A expression modulates voltage-gated Ca2+ influx in a voltage-independent manner and recent studies also demonstrate a complex role of TMEM16A in modulating other membrane proteins. 相似文献
40.
Samson Mani Katarzyna Szymańska Cyrille Cuenin David Zaridze Karen Balassiano Sheila CS Lima Elena Matos Alexander Daudt Sergio Koifman Victor Wunsch Filho Ana MB Menezes Maria Paula Curado Gilles Ferro Thomas Vaissière Bakary S Sylla Massimo Tommasino Luis Felipe Ribeiro Pinto Paolo Boffetta Pierre Hainaut Paul Brennan Zdenko Herceg 《Epigenetics》2012,7(3):270-277
Cancers of the upper aerodigestive tract (UADT) are common forms of malignancy associated with tobacco and alcohol exposures, although human papillomavirus and nutritional deficiency are also important risk factors. While somatically acquired DNA methylation changes have been associated with UADT cancers, what triggers these events and precise epigenetic targets are poorly understood. In this study, we applied quantitative profiling of DNA methylation states in a panel of cancer-associated genes to a case-control study of UADT cancers. Our analyses revealed a high frequency of aberrant hypermethylation of several genes, including MYOD1, CHRNA3 and MTHFR in UADT tumors, whereas CDKN2A was moderately hypermethylated. Among differentially methylated genes, we identified a new gene (the nicotinic acetycholine receptor gene) as target of aberrant hypermethylation in UADT cancers, suggesting that epigenetic deregulation of nicotinic acetycholine receptors in non-neuronal tissues may promote the development of UADT cancers. Importantly, we found that sex and age is strongly associated with the methylation states, whereas tobacco smoking and alcohol intake may also influence the methylation levels in specific genes. This study identifies aberrant DNA methylation patterns in UADT cancers and suggests a potential mechanism by which environmental factors may deregulate key cellular genes involved in tumor suppression and contribute to UADT cancers.Key words: DNA methylation, upper aerodigestive tract, cancer, risk factors, biomarkers 相似文献