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421.
Richard Biebl 《Protoplasma》1959,50(3):321-339
Ohne Zusammenfassung 相似文献
422.
Adrián García-Rodríguez Bernd Lenzner Clara Marino Chunlong Liu Julián A. Velasco Céline Bellard Jonathan M. Jeschke Hanno Seebens Franz Essl 《Global Change Biology》2023,29(17):4924-4938
Shifts between native and alien climatic niches pose a major challenge for predicting biological invasions. This is particularly true for insular species because geophysical barriers could constrain the realization of their fundamental niches, which may lead to underestimates of their invasion potential. To investigate this idea, we estimated the frequency of shifts between native and alien climatic niches and the magnitude of climatic mismatches using 80,148 alien occurrences of 46 endemic insular amphibian, reptile, and bird species. Then, we assessed the influence of nine potential predictors on climatic mismatches across taxa, based on species' characteristics, native range physical characteristics, and alien range properties. We found that climatic mismatch is common during invasions of endemic insular birds and reptiles: 78.3% and 55.1% of their respective alien records occurred outside of the environmental space of species' native climatic niche. In comparison, climatic mismatch was evident for only 16.2% of the amphibian invasions analyzed. Several predictors significantly explained climatic mismatch, and these varied among taxonomic groups. For amphibians, only native range size was associated with climatic mismatch. For reptiles, the magnitude of climatic mismatch was higher for species with narrow native altitudinal ranges, occurring in topographically complex or less remote islands, as well as for species with larger distances between their native and alien ranges. For birds, climatic mismatch was significantly larger for invasions on continents with higher phylogenetic diversity of the recipient community, and when the invader was more evolutionarily distinct. Our findings highlight that apparently common niche shifts of insular species may jeopardize our ability to forecast their potential invasions using correlative methods based on climatic variables. Also, we show which factors provide additional insights on the actual invasion potential of insular endemic amphibians, reptiles, and birds. 相似文献
423.
424.
Richard Biebl 《Protoplasma》1964,59(2):277-297
Ohne Zusammenfassung 相似文献
425.
426.
H Biebl 《Journal of industrial microbiology & biotechnology》1999,22(2):115-120
The butanol and acetone-producing strain DSM 2152, invalidly described as ‘Clostridium saccharoperbutylacetonicum’ is compared with the type strain C. acetobutylicum, DSM 792, with respect to solvent and acid formation at varying pH values and growth rates. Batch cultures, product-limited
chemostat and pH-auxostat cultures were used for characterization. Under all conditions strain DSM 2152 produced much lower
amounts of butyric and acetic acids than the type strain. The pH optimum for solvent formation was higher, ie 5.5 instead
of 4.5. Solvent formation occurred at higher dilution rates, but below 0.1 h−1 a lower solvent concentration was obtained, indicating that acid production was too low to provide a sufficient amount for
acetone formation. The results are discussed in the light of recent publications on the taxonomy of butanol-acetone producing
clostridia using 16S rRNA sequence analysis and other nucleic acid data. The presently suggested ‘phylogenetic’ classification
of the collective species, C. acetobutylicum, is also reflected in the fermentation characteristics.
Received 21 December 1998/ Accepted in revised form 22 January 1999 相似文献
427.
Richard Biebl 《Plant Systematics and Evolution》1954,101(5):502-538
Ohne Zusammenfassung 相似文献
428.
Ohne Zusammenfassung 相似文献
429.
J. Berger Marion Gmach Ingrid Faé Brunhilde Molzer Hanno Bernheimer 《Human genetics》1996,98(3):348-350
A 10-year-old boy with juvenile metachromatic leukodystrophy (MLD) presented with the 459 + 1G→A arylsulfatase A (ASA) mutation
on one allele. To detect his complete genotype, the other ASA allele was sequenced and a T-to-C transition at nucleotide 376
in exon 2 was identified. This missense mutation results in a substitution of leucine 76 by proline. Of 20 MLD unrelated controls,
18 carried the L/P76 mutation either in the homozygous (n = 6) or heterozygous (n = 12) state. The presence or absence of L/P76 did not influence leukocyte ASA activity or urinary sulfatide excretion. Apparently,
the substitution of leucine 76 by proline is a common ASA polymorphism, neither being related to MLD nor creating ASA pseudodeficiency.
However, because of its frequency and location, L/P76 may be of particular importance in genetic studies requiring the differentiation
of the ASA alleles within a kindred. Further studies are directed to the as yet unresolved genotype of the index case with
juvenile MLD.
Received: 5 March 1996 / Revised: 16 April 1996 相似文献
430.
Jan H.N. Lindeman M.D. Ph.D. Hanno Pijl François M.H. van Dielen Eef G.W.M. Lentjes Cees van Leuven Teake Kooistra 《Obesity (Silver Spring, Md.)》2002,10(11):1161-1166
Objective: Human obesity is characterized by growth hormone (GH) deficiency, which appears primarily related to a central pattern of obesity and is reverted on weight loss. As yet, the metabolic basis of the GH deficiency remains to be elucidated. The recently discovered endogenous ligand for the GH secretagogue receptor, ghrelin, stimulates GH secretion when administered to rodents or healthy humans. It may thus be hypothesized that low ghrelin levels underlie the hyposomatropism in obesity. Research Methods and Procedures: We have tested this hypothesis in individuals with widely varying body mass and fat distribution and evaluated whether the improved GH concentrations on weight loss are associated with enhanced ghrelin levels. Results: Both plasma GH and ghrelin levels were reciprocally related with body mass index (r = −0.67, p < 0.001). However, whereas 24-hour GH secretion was negatively related to the visceral fat area (r = −0.72, p < 0.01), ghrelin levels showed a positive relationship with the visceral fat area (r = 0.49, p < 0.02). Weight loss resulted in increased GH secretion (median 24-hour GH area under the curve: 1983 vs. 4024 mU/day before and after weight loss, respectively; p < 0.01) but did not affect ghrelin levels. No relationship could be found between GH and ghrelin plasma levels in obese subjects when comparing diurnal concentration profiles. Discussion: We showed that plasma ghrelin and GH levels are both reciprocally related with body mass index, but no causative relationship could be demonstrated between low ghrelin levels and the hyposomatropism in human obesity. 相似文献