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Raba’atun Adawiyah S. Shuhaimi M. Mohd Yazid A. M. Abdul Manaf A. Rosli N. Sreeramanan S. 《World journal of microbiology & biotechnology》2011,27(9):2173-2185
Selected endophytic fungi have been report to be inulin degraders to produce fructose or other oligosaccharides. In this study,
the Aspergillus sp. producing inulinase were isolated from selected plant species at Serdang area in Malaysia. Fungal isolates were screened
solely based on inulin degrading enzymes production and two isolates named Asf1 and Onf1 were selected as the best inulinase
enzyme producers. Genomic DNA of these two isolates were extracted and amplified by polymerase chain reaction (PCR). A 1,341 bp
DNA fragment containing inulinase gene was successfully amplified from Asf1 fungal isolate and was named as inu2 gene in this study. Based on the morphological characteristics, rDNA and neighbour-joining phylogenetic analysis, Asf1 fungal
isolate could display closely-related to the genus of Aspergillus. The complete sequence designated Asf1 Inu2 gene was successfully obtained via rapid-amplification of cDNA ends-polymerase chain reaction (RACE-PCR). A 2.3 kb DNA fragment
encoding endoinulinase, inu2, from Asf1 fungal isolate includes an open reading frame of 1,552 bp with calculated molecular weight of 55,954.1 Da and
signal peptide sequence of 23 amino acids. The deduced amino acid sequence of the Asf1 inu2 displayed 97, 96, 69 and 22% identities
to that of A. ficuum inu2, A. niger inuB, P. purpurogenum and K. marxianus, respectively. Phylogenetic analysis showed that fungal endo- and exo-inulinases have indepently evolved with the respective
hydrolytic activities toward terminal and internal β-(2 → 1)-fructofuranosidic linkages in inulin. 相似文献
24.
Nanyan?Noreen Wei?Yeng?Hooi Ali?Baradaran Mohamad?Rosfarizan Chin?Chin?Sieo Md?Illias?Rosli Khatijah?Yusoff Abdul?Rahim?RahaEmail author 《Microbial cell factories》2011,10(1):28
Background
Many plasmid-harbouring strains of Lactococcus lactis have been isolated from milk and other sources. Plasmids of Lactococcus have been shown to harbour antibiotic resistance genes and those that express some important proteins. The generally regarded as safe (GRAS) status of L. lactis also makes it an attractive host for the production of proteins that are beneficial in numerous applications such as the production of biopharmaceutical and nutraceutical. In the present work, strains of L. lactis were isolated from cow's milk, plasmids were isolated and characterised and one of the strains was identified as a potential new lactococcal host for the expression of heterologous proteins. 相似文献25.
Abstract. Workers of Crematogaster inflata possess the largest metapleural glands (relative to body size) known among ants, with reservoirs extending anteriorly up to the junction between the pro‐ and the mesothorax, and with over 1400 secretory cells on both sides together. This large secretory capacity is related to the gland's defensive function, which, in members of this species, is directed against larger arthropod and vertebrate enemies, and apparently not against microorganisms, in contrast to other ants, where the gland produces antibiotics. The gland is not equipped with any direct musculature. Secretion release is probably caused by contraction of the oblique longitudinal thorax muscles or by passive expulsion caused by external pressure. 相似文献
26.
Low KO Mahadi NM Rahim RA Rabu A Abu Bakar FD Murad AM Illias RM 《Journal of industrial microbiology & biotechnology》2011,38(9):1587-1597
Direct transport of recombinant protein from cytosol to extracellular medium offers great advantages, such as high specific
activity and a simple purification step. This work presents an investigation on the potential of an ABC (ATP-binding cassette)
transporter system, the hemolysin transport system, for efficient protein secretion in Escherichia coli (E. coli). A higher secretory production of recombinant cyclodextrin glucanotransferase (CGTase) was achieved by a new plasmid design
and subsequently by optimization of culture conditions via central composite design. An improvement of at least fourfold extracellular
recombinant CGTase was obtained using the new plasmid design. The optimization process consisted of 20 experiments involving
six star points and six replicates at the central point. The predicted optimum culture conditions for maximum recombinant
CGTase secretion were found to be 25.76 μM IPTG, 1.0% (w/v) arabinose and 34.7°C post-induction temperature, with a predicted
extracellular CGTase activity of 68.76 U/ml. Validation of the model gave an extracellular CGTase activity of 69.15 ± 0.71 U/ml,
resulting in a 3.45-fold increase compared to the initial conditions. This corresponded to an extracellular CGTase yield of
about 0.58 mg/l. We showed that a synergistic balance of transported protein and secretory pathway is important for efficient
protein transport. In addition, we also demonstrated the first successful removal of the C-terminal secretion signal from the transported fusion protein by thrombin proteolytic cleavage. 相似文献
27.
Evolutionary medicine is a perspective on medical sciences derived through application of theory of evolution to aid in therapeutics.
This study sought to determine the level of knowledge and acceptance of evolutionary theory in medical students along with
their attitude toward teaching evolutionary medicine as a part of their undergraduate course. Factors that are likely to cause
difficulty in teaching evolutionary medicine were also identified. A cross-sectional study was carried out at Army Medical
College, National University of Sciences and Technology, Pakistan in which 299 medical students were selected by nonprobability
convenient sampling technique to participate in the study. Participants’ views were obtained by a structured questionnaire
comprised of three sections: appreciation of evolutionary medicine, acceptance of evolutionary theory, knowledge of evolutionary
theory. Medical students had a low acceptance [mean measure of acceptance of theory of evolution (MATE) = 58.32] and a low
knowledge (mean score of 5.20 out of a total ten marks). Students believed that religious beliefs, lack of resources, and
an existent extensive medical curriculum would cause difficulty in imparting such an education despite its potential to improve
medical research and clinical practice. Only 37.2% agreed that the subject should be taught in medical schools as an individual
subject. 相似文献
28.
Wahl M Link H Alexandridis N Thomason JC Cifuentes M Costello MJ da Gama BA Hillock K Hobday AJ Kaufmann MJ Keller S Kraufvelin P Krüger I Lauterbach L Antunes BL Molis M Nakaoka M Nyström J bin Radzi Z Stockhausen B Thiel M Vance T Weseloh A Whittle M Wiesmann L Wunderer L Yamakita T Lenz M 《PloS one》2011,6(5):e19514
Species richness is the most commonly used but controversial biodiversity metric in studies on aspects of community stability such as structural composition or productivity. The apparent ambiguity of theoretical and experimental findings may in part be due to experimental shortcomings and/or heterogeneity of scales and methods in earlier studies. This has led to an urgent call for improved and more realistic experiments. In a series of experiments replicated at a global scale we translocated several hundred marine hard bottom communities to new environments simulating a rapid but moderate environmental change. Subsequently, we measured their rate of compositional change (re-structuring) which in the great majority of cases represented a compositional convergence towards local communities. Re-structuring is driven by mortality of community components (original species) and establishment of new species in the changed environmental context. The rate of this re-structuring was then related to various system properties. We show that availability of free substratum relates negatively while taxon richness relates positively to structural persistence (i.e., no or slow re-structuring). Thus, when faced with environmental change, taxon-rich communities retain their original composition longer than taxon-poor communities. The effect of taxon richness, however, interacts with another aspect of diversity, functional richness. Indeed, taxon richness relates positively to persistence in functionally depauperate communities, but not in functionally diverse communities. The interaction between taxonomic and functional diversity with regard to the behaviour of communities exposed to environmental stress may help understand some of the seemingly contrasting findings of past research. 相似文献
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Sahidin Hakim EH Juliawaty LD Syah YM bin Din L Ghisalberti EL Latip J Said IM Achmad SA 《Zeitschrift für Naturforschung. C, Journal of biosciences》2005,60(9-10):723-727
A new modified stilbene dimer, diptoindonesin D (1), was isolated from the acetone extract of the tree bark of Hopea dryobalanoides, together with seven known compounds, parviflorol (2), (-)-balanocarpol (3), heimiol A (4), hopeafuran (5), (+)-alpha-viniferin (6), vaticanol B (7) and (-)-hopeaphenol (8). Cytotoxic properties of compounds 1-8 were evaluated against murine leukemia P-388 cells. Compound 8 was found to be the most active with IC50 of 5.7 microM. 相似文献