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991.
Curcumin, a principle bioactive component of Curcuma longa L, is well known for its anti-hyperlipidemia effect. However, no holistic metabolic information of curcumin on hyperlipidemia models has been revealed, which may provide us an insight into the underlying mechanism. In the present work, NMR and MS based metabolomics was conducted to investigate the intervention effect of curcumin on hyperlipidemia mice induced by high-fat diet (HFD) feeding for 12 weeks. The HFD induced animals were orally administered with curcumin (40, 80 mg/kg) or lovastatin (30 mg/kg, positive control) once a day during the inducing period. Serum biochemistry assay of TC, TG, LDL-c, and HDL-c was conducted and proved that treatment of curcumin or lovastatin can significantly improve the lipid profiles. Subsequently, metabolomics analysis was carried out for urine samples. Orthogonal Partial Least Squares-Discriminant analysis (OPLS-DA) was employed to investigate the anti-hyperlipidemia effect of curcumin and to detect related potential biomarkers. Totally, 35 biomarkers were identified, including 31 by NMR and nine by MS (five by both). It turned out that curcumin treatment can partially recover the metabolism disorders induced by HFD, with the following metabolic pathways involved: TCA cycle, glycolysis and gluconeogenesis, synthesis of ketone bodies and cholesterol, ketogenesis of branched chain amino acid, choline metabolism, and fatty acid metabolism. Besides, NMR and MS based metabolomics proved to be powerful tools in investigating pharmacodynamics effect of natural products and underlying mechanisms. 相似文献
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994.
Haiqiang Lu Huiying Luo Pengjun Shi Huoqing Huang Kun Meng Peilong Yang Bin Yao 《Applied microbiology and biotechnology》2014,98(5):2155-2163
The gene man5XZ3 from Aspergillus nidulans XZ3 encodes a multimodular β-mannanase of glycoside hydrolase family 5 that consists of a family 1 carbohydrate-binding module (CBM1), a Thr/Ser-rich linker region, and a catalytic domain. Recombinant Man5XZ3 and its two truncated derivatives, Man5ΔCBM (removing the CBM1) and Man5ΔCL (removing both the CBM1 and linker region), were produced in Pichia pastoris and showed significant variance in the secondary structure. The three enzymes had similar biochemical properties, such as optimal pH and temperature (pH 5.0 and 80 °C) and excellent pH stability at pH 4.0–10.0. Removal of the CBM1 alone could improve the thermostability of Man5XZ3, but further removal of the linker region resulted in worse thermostability. Man5XZ3 retained greater enzyme activity in the presence of an organic solvent (acetone), two detergents (SDS and Triton X-100), and a chaotropic agent (urea) compared with Man5ΔCBM and Man5ΔCL. This study provides an excellent β-mannanase candidate favorable for various industries and primarily demonstrates the relationship between enzyme structure and function. 相似文献
995.
Keoagile W. Modisakeng Meesbah Jiwaji Eva-Rachele Pesce Jacques Robert Chris T. Amemiya Rosemary A. Dorrington Gregory L. Blatch 《Molecular genetics and genomics : MGG》2009,282(2):185-196
Molecular chaperones facilitate the correct folding of other proteins, and heat shock proteins form one of the major classes
of molecular chaperones. Heat shock protein 70 (Hsp70) has been extensively studied, and shown to be critically important
for cellular protein homeostasis in almost all prokaryotic and eukaryotic systems studied to date. Since there have been very
limited studies conducted on coelacanth chaperones, the main objective of this study was to genetically and biochemically
characterize a coelacanth Hsp70. We have successfully isolated an Indonesian coelacanth (L. menadoensis) hsp70 gene, Lmhsp70, and found that it contained an intronless coding region and a potential upstream regulatory region. Lmhsp70 encoded a typical Hsp70 based on conserved structural and functional features, and the predicted upstream regulatory region
was found to contain six potential promoter elements, and three potential heat shock elements (HSEs). The intronless nature
of the coding region and the presence of HSEs suggested that Lmhsp70 was stress-inducible. Phylogenetic analyses provided further evidence that Lmhsp70 was probably inducible, and that it branched as a clade intermediate between bony fish and tetrapods. Recombinant LmHsp70
was successfully overproduced, purified and found to be functional using ATPase activity assays. Taken together, these data
provide evidence for the first time that the coelacanth encodes a functional molecular chaperone system.
K. W. Modisakeng and M. Jiwaji contributed equally to this study. 相似文献
996.
We report the observation of two types of changes in fluorescence spectra of LHCII at 4.2 K following intense illumination
of the sample with a spectrally narrow laser beam at wavelengths between 678 and 686 nm. Nonspecific changes (burning-wavelength
independent) are characterized by two relatively broad bands: a positive one at ∼ 678.7 nm and a negative one at ∼ 680.8 nm.
These changes reveal a ∼1.3-nm blue shift of the distribution of final emitters in LHCII, from 680.3 nm to ∼ 679.0 nm independent
of the excitation wavelength. Specific fluorescence changes (burning-wavelength dependent) are characterized by a sharp hole
exactly at the burning wavelength, and positive changes directly to the shorter-and longer-wavelength side of the narrow hole.
The negative changes are interpreted as zero-phonon holes, while the positive features are assigned to non-photochemical products.
In the low-burning intensity experiment, in addition to the zero-phonon holes, we observed also the holes to the longer wavelength
of the zero-phonon hole, which were assigned to a sum of phonon and pseudo-phonon side bands. The shapes of these extra holes
are identical to the shapes of the holes revealed in the fluorescence line narrowing experiment. On the basis of the low-burning
intensity experiment we estimated the upper limit of the electron-phonon coupling strength for LHCII, characterized by a Huang-Rhys
factor of 1.5. 相似文献
997.
Efficient somatic embryogenesis (SE) and in vitro flowering and fruiting were achieved in Saposhnikovia divaricata (Turcz.) Schischk. Friable embryogenic callus developed from the root, internode, and leaf explants on Murashige and Skoog
medium (MS) with 2.26 μM 2,4-dichlorophenoxyacetic acid (2,4-D), and subsequently developed into somatic embryos on MS medium
containing 4–5% sucrose, 1.74 μM naphthaleneacetic acid (NAA), 4.44 μM 6-benzylaminopurine (BA), and 1.90 μM abscisic acid
(ABA). Then the mature embryos were separated and transferred onto MS with 3% sucrose and 0.6% agar for further development
and conversion to plantlets. In vitro flowering and fruiting were obtained when the subcultures were carried out for over
15 months. Paclobutrazol (PP333) or ethephon (ETH) at low levels promoted flowering significantly. Also, abnormal rootless
somatic embryos of S. divaricata could form flowers and fruits in vitro. 相似文献
998.
Guang-Rong Zhao Ting Luo Yong-Jin Zhou Xin Jiang Bin Qiao Feng-Ming Yu Ying-Jin Yuan 《Applied microbiology and biotechnology》2009,83(2):305-313
Streptolydigin, a secondary metabolite produced by Streptomyces lydicus, is a potent inhibitor of bacterial RNA polymerases. It has been suggested that streptolydigin biosynthesis is associated
with polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS). Thus, there is great interest in understanding
the role of fatty acid biosynthesis in the biosynthesis of streptolydigin. In this paper, we cloned a type II fatty acid synthase
(FAS II) gene cluster of fabDHCF from the genome of S. lydicus and constructed the SlyfabCF-disrupted mutant. Sequence analysis showed that SlyfabDHCF is 3.7 kb in length and encodes four separated proteins with conserved motifs and active residues, as shown in the FAS II
of other bacteria. The SlyfabCF disruption inhibited streptolydigin biosynthesis and retarded mycelial growth, which were likely caused by the inhibition
of fatty acid synthesis. Streptolydigin was not detected in the culture of the mutant strain by liquid chromatography–mass
spectrometry. Meanwhile, the streptolol moiety of streptolydigin accumulated in cultures. As encoded by fabCF, acyl carrier protein (ACP) and β-ketoacyl-ACP synthase II are required for streptolydigin biosynthesis and likely involved
in the step between PKS and NRPS. Our results provide the first genetic and metabolic evidence that SlyfabCF is shared by fatty acid synthesis and antibiotic streptolydigin synthesis. 相似文献
999.
Summary . Functional mapping is a useful tool for mapping quantitative trait loci (QTL) that control dynamic traits. It incorporates mathematical aspects of biological processes into the mixture model-based likelihood setting for QTL mapping, thus increasing the power of QTL detection and the precision of parameter estimation. However, in many situations there is no obvious functional form and, in such cases, this strategy will not be optimal. Here we propose to use nonparametric function estimation, typically implemented with B-splines, to estimate the underlying functional form of phenotypic trajectories, and then construct a nonparametric test to find evidence of existing QTL. Using the representation of a nonparametric regression as a mixed model, the final test statistic is a likelihood ratio test. We consider two types of genetic maps: dense maps and general maps, and the power of nonparametric functional mapping is investigated through simulation studies and demonstrated by examples. 相似文献
1000.
Coexistence of nitrifiers, denitrifiers and Anammox bacteria in a sequencing batch biofilm reactor as revealed by PCR-DGGE 总被引:3,自引:0,他引:3
Y. Xiao G.M. Zeng Z.H. Yang Y.Sh. Liu Y.H. Ma L. Yang R.J. Wang Zh.Y. Xu 《Journal of applied microbiology》2009,106(2):496-505
Aims: The bacterial diversity in a sequencing batch biofilm reactor (SBBR) treating landfill leachate was studied to explain the mechanism of nitrogen removal.
Methods and Results: The total microbial DNA was extracted from samples collected from landfill leachate and biofilm of the reactor with the removal efficiencies of NH4 + -N higher than 97% and that of chemical oxygen demand (determined by K2 Cr2 O7 , CODCr ) higher than 86%. Denaturing gradient gel electrophoresis (DGGE) fingerprints based on total community 16S rRNA genes were analyzed with statistical methods, and excised DNA bands were sequenced. The results of phylogenetic analyses revealed high diversity within the SBBR biofilm community, and DGGE banding patterns showed that the community structure in the biofilm remained stable during the running period.
Conclusions: A coexistence of nitrifiers, including ammonia-oxidizing bacteria and nitrite-oxidizing bacteria, denitrifiers, including aerobic or anaerobic denitrifying bacteria and Anammox bacteria were detected, which might be the real matter of high removal efficiencies of NH4 + -N and CODCr in the reactor.
Significance and Impact of the Study: The findings in this study indicated that PCR-DGGE analysis could be used for microbial community detection as prior method, and the SBBR technique could provide preferable growing environment for bacteria with N removal function. 相似文献
Methods and Results: The total microbial DNA was extracted from samples collected from landfill leachate and biofilm of the reactor with the removal efficiencies of NH
Conclusions: A coexistence of nitrifiers, including ammonia-oxidizing bacteria and nitrite-oxidizing bacteria, denitrifiers, including aerobic or anaerobic denitrifying bacteria and Anammox bacteria were detected, which might be the real matter of high removal efficiencies of NH
Significance and Impact of the Study: The findings in this study indicated that PCR-DGGE analysis could be used for microbial community detection as prior method, and the SBBR technique could provide preferable growing environment for bacteria with N removal function. 相似文献