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131.
132.
Daniel Hagège Claire Kevers Philippe Salabert Thomas Gaspar 《In vitro cellular & developmental biology. Plant》1992,28(3):143-147
Summary The levels of the water-soluble reductants ascorbic acid and glutathione and the activities of the enzymatic antioxidants
superoxide dismutase, catalase, ascorbate peroxidase, monodehydroascorbate and dehydroascorbate reductases and glutathione
reductase were determined in a fully habituated nonorganogenic sugarbeet callus line (considered a neoplasm) compared with
a normal hormone-dependent callus of the same plant. Ascorbic acid was not recovered from either of the two calluses, irrespective
of the technique used. Glutathione was titrated at a slightly higher level in the normal callus. Catalase activity was almost
nonexistent in the habituated callus. The other enzymes (superoxide dismutase, glutathione reductase, monodehydroascorbate
reductase, dehydroascorbate reductase, and ascorbate peroxidase) were found to have higher activities in the habituated callus.
The results are interpreted as a higher protection of the neoplastic habituated cells against oxygen-free radicals and hydroperoxide-dependent
oxidations. Such strong scavenging properties of the habituated cell line could explain previous results already reported,
namely the stimulation of cell division at the expense of cell differentiation. 相似文献
133.
Claire Kevers Nicole Boyer Jean-Claude Courduroux Thomas Gaspar 《Plant Cell, Tissue and Organ Culture》1992,28(2):175-181
Ethylene accumulation in four different rose in vitro culture containers was evaluated. Multiplication rate was the highest, and axes most elongated, in the two containers where ethylene accumulation was limited. Pulse treatments of ethylene at various concentrations enhanced proliferation depending on concentration (5 ppm generally was the most favourable) and time of application, while reducing elongation of the shoots. An ethylene trap in the flask atmospheres of the cultures reduced rose shoot proliferation rate but increased elongation of the axes. Inhibitors of ethylene biosynthesis, aminoethoxyvinylglycine (AVG) and cobalt chloride (CoCl2), increased multiplication rate by providing a higher number of axes of a suitable size for subculture. The ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) had a beneficial effect on multiplication rate, although reducing longitudinal growth of the axes.Abbreviations ACC
1-aminocyclopropane-1-carboxylic acid
- AVG
aminoethoxyvinylglycine
- BA
benzyladenine
- GA3
gibberellic acid
- IBA
indolyl-3-butyric acid 相似文献
134.
Correlation between CAG Repeat Length and Clinical Features in Machado-Joseph Disease 总被引:19,自引:3,他引:16
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Patrícia Maciel Claudia Gaspar Anita L. DeStefano Isabel Silveira Paula Coutinho Joo Radvany David M. Dawson Lewis Sudarsky Joo Guimares Jose E. L. Loureiro Marjan M. Nezarati Lee I. Corwin Iscia Lopes-Cendes Karen Rooke Roger Rosenberg Patrick MacLeod Lindsay A. Farrer Jorge Sequeiros Guy A. Rouleau 《American journal of human genetics》1995,57(1):54-61
Machado-Joseph disease (MJD) is associated with the expansion of a CAG trinucleotide repeat in a novel gene on 14q32.1. We confirmed the presence of this expansion in 156 MJD patients from 33 families of different geographic origins: 15 Portuguese Azorean, 2 Brazilian, and 16 North American of Portuguese Azorean descent. Normal chromosomes contain between 12 and 37 CAG repeats in the MJD gene, whereas MJD gene carriers have alleles within the expanded range of 62–84 CAG units. The distribution of expanded alleles and the gap between normal and expanded allele sizes is either inconsistent with a premutation hypothesis or most (if not all) of the alleles we studied descend from a common ancestor. There is a strong correlation between the expanded repeat size and the age at onset of the disease as well as the clinical presentation. There is mild instability of the CAG tract length with transmission of the expanded alleles; both increase and decrease in size between parents and progeny occur, with larger variations in male than in female transmissions. Together, these effects can partly explain the variability of age at onset and of phenotypic features in MJD; however, other modifying factors must exist. 相似文献
135.
Vitrification of shoots of Prunus avium L. L. was induced and expressed in a four week in vitro multiplication cycle simply by replacing agar by gelrite. The first vitrification symptoms were visible from the 7th day on. Enzymatic antioxidants were compared weekly in crude extract of normal (on agar) and vitrifying (on gelrite) shoots. The activity of superoxide dismutase was higher in vitrifying shoots. The other enzymes (gaîacol-peroxidase, catalase, ascorbate peroxidase, mono- and dehydro-ascorbate reductases, glutathione reductase) had lower activities. Increased superoxide dismutase activity might mean hydrogen peroxide accumulation and decreased activities of the other enzymes, deficiency in its detoxification. The question therefore is raised whether the hyperhydric morphological abnormalities result from the accumulation of toxic oxygen forms. Vitrification is often considered as a morphological response to several stresses. Contrary to most plants which adapt themselves to stresses by increasing all the above defence enzymes, in vitro shoots under vitrifying conditions appear unable to react in a similar manner.Abbreviations Apx
ascorbate peroxidase
- Gpx
gaîacol peroxidase
- CAT
catalase
- H2O2
hydrogen peroxide
- SOD
superoxide dismutase
- MDHAR
monodehydroascorbate reductase
- DHAR
dehydroascorbate reductase
- GR
glutathione reductase
- MS
Murashige and Skoog (1962)
- IBA
indolebutyric acid
- BAP
benzyladenine
- GA3
gibberellic acid 相似文献
136.
Plant hormones and plant growth regulators in plant tissue culture 总被引:13,自引:0,他引:13
Thomas Gaspar Claire Kevers Claude Penel Hubert Greppin David M. Reid Trevor A. Thorpe 《In vitro cellular & developmental biology. Plant》1996,32(4):272-289
Summary This is a short review of the classical and new, natural and synthetic plant hormones and growth regulators (phytohormones)
and highlights some of their uses in plant tissue culture. Plant hormones rarely act alone, and for most processes— at least
those that are observed at the organ level—many of these regulators have interacted in order to produce the final effect.
The following substances are discussed: (a) Classical plant hormones (auxins, cytokinins, gibberellins, abscisic acid, ethylene
and growth regulatory substances with similar biological effects. New, naturally occurring substances in these categories
are still being discovered. At the same time, novel structurally related compounds are constantly being synthesized. There
are also many new but chemically unrelated compounds with similar hormone-like activity being produced. A better knowledge
of the uptake, transport, metabolism, and mode of action of phytohormones and the appearance of chemicals that inhibit synthesis,
transport, and action of the native plant hormones has increased our knowledge of the role of these hormones in growth and
development. (b) More recently discovered natural growth substances that have phytohormonal-like regulatory roles (polyamines,
oligosaccharins, salicylates, jasmonates, sterols, brassinosteroids, dehydrodiconiferyl alcohol glucosides, turgorins, systemin,
unrelated natural stimulators and inhibitors), as well as myoinositol. Many of these growth active substances have not yet
been examined in relation to growth and organized developmentin vitro. 相似文献
137.
Eva Talavera-Garcia Javier Delgado-Lista Antonio Garcia-Rios Nieves Delgado-Casado Purificacion Gomez-Luna Angela Gomez-Gardu?o Francisco Gomez-Delgado Juan F. Alcala-Diaz Elena Yubero-Serrano Carmen Marin Ana I. Perez-Caballero Francisco J. Fuentes-Jimenez Antonio Camargo Fernando Rodriguez-Cantalejo Francisco J. Tinahones Jose M. Ordovas Francisco Perez- Jimenez Pablo Perez-Martinez Jose Lopez-Miranda 《PloS one》2016,11(6)
138.
Manuel de Sousa Almeida Pedro de Araújo Gon?alves Patricia Branco Jo?o Mesquita Maria Salomé Carvalho Helder Dores Henrique Silva Sousa Augusta Gaspar Eduarda Horta Ana Aleixo Nuno Neuparth Miguel Mendes Maria Jo?o Andrade 《PloS one》2016,11(3)
Background
Catheter-based sympathetic renal denervation (RDN) is a recent therapeutic option for patients with resistant hypertension. However, the impact of RDN in left ventricular (LV) mass and function is not completely established. Our aim was to evaluate the effects of RDN on LV structure and function (systolic and diastolic) in patients with resistant hypertension (HTN).Methods and Results
From a single centre prospective registry including 65 consecutive patients with resistant HTN submitted to RDN between July-2011 and April-2015, 31 patients with baseline and 1-year follow-up echocardiogram were included in this analysis. Mean age was 65±7 years, 48% were males, 71% had type 2 diabetes. Most had hypertension lasting for more than 10 years (90%), and were being treated with a median number of 6 anti-hypertensive drugs, including 74% on spironolactone. At 1-year, there was a significant decrease both on office SBP (176±24 to 149±13mmHg, p<0.001) and DBP (90±14 to 79±11mmHg, p<0.001), and also in 24h ABPM SBP (150±20 to 132±14mmhg, p<0.001) and DBP (83±10 to 74±9mmHg, p<0.001). There was also a significant decrease in LV mass from 152±32 to 136±34g/m2 (p<0.001), an increase in LV end diastolic volume (93±18 to 111±27 mL, p = 0.004), an increase in LV ejection fraction (65±9 to 68±9%, p = 0.001) and mitral valve E deceleration time (225±49 to 247±51ms, p = 0.015) at 1-year follow up. There were no significant changes in left atrium volume index or in the distribution of patients among the different left ventricle geometric patterns and diastolic function subgroups.Conclusions
In this single centre registry of patients with resistant hypertension, renal denervation was associated with significant reduction in both office and ABPM blood pressure and a significant decrease in left ventricle mass evaluated by transthoracic echocardiogram at 1 year follow-up. 相似文献139.
Conjugates of goat anti-HBs IgG and horseradish peroxidase (HRP) prepared by two different methods, one using NaIO4 and the other SPDP, were compared. Anti-HBs antibodies obtained from goat, rabbit and guinea-pig were tested as capture serum. The ELISA showed a sensitivity similar to RIA and a level of antigen captation ranging from 4.37 to 8.75 nanograms/ml was obtained when rabbit or guinea-pig captures were used combined with both NaIO4 or SPDP conjugates. 相似文献
140.
G. Barbin J. M. Palacios M. Garbarg J. C. Schwartz P. Gaspar F. Javoy-Agid Y. Agid 《Journal of neurochemistry》1980,35(2):400-406
The properties of the histamine-forming enzyme in human brain samples were studied utilizing a radiochromatographic procedure. The influence of postmortem conditions was checked with rat brains, and the results indicated that the enzyme activity is not altered in situ for a delay not exceeding 4 h at ambient temperature. Moreover, tissue blocks or homogenates can be stored at low temperatures for up to 3 months with a good preservation of the enzyme activity. The data indicate that histamine synthesis in the human brain involves the ?specific” histidine decarboxylase (HD, EC 4.1.1.22) and not the aromatic l -amino acid decarboxylase; (1) the optimum pH is 7.4 at 10-6m-l -histidine; (2) the apparent Km is about 3.10-5m ; (3) it is inhibited by α-hydrazino histidine and brocresine but not affected by α-methyl DOPA. Moreover, a major portion of the enzyme is localized in a subcellular fraction containing nerve terminals and it shows an uneven regional distribution which parallels that observed in the brain of other mammalian species. Taken together these data strongly suggest that histamine could play a neurotransmitter role in the human brain. 相似文献