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91.
Arumugam Karthikeyan 《Symbiosis (Philadelphia, Pa.)》2017,72(2):89-94
Impact of different levels of elevated CO 2 on the activity of Frankia (Nitrogen-fixing actinomycete) in Casuarina equisetifolia rooted stem cuttings has been studied to understand the relationship between C. equisetifolia, Frankia and CO2. The stem cuttings of C. equietifolia were collected and treated with 2000 ppm of Indole Butyric Acid (IBA) for rooting. Thus vegetative propagated rooted stem cuttings of C. equisetifolia were inoculated with Frankia and placed in the Open top chambers (OTC) with elevated CO2 facilities. These planting stocks were maintained in the OTC for 12 months under different levels of elevated CO2 (ambient control, 600 ppm, 900 ppm). After 12 months, the nodule numbers, bio mass, growth, and photosynthesis of C. equisetifolia rooted stem cuttings inoculated with Frankia were improved under 600 ppm of CO2. The rooted stem cuttings of C. equisetifolia inoculated with Frankia showed a higher number of nodules under 900 ppm of CO2 and cuttings without Frankia inoculation exhibited poor growth. Tissue Nitrogen (N) content was also higher under 900 ppm of CO2 than ambient control and 600 ppm levels. The photosynthetic rate was higher (17.8 μ mol CO2 m?2 s?1) in 900 ppm of CO2 than in 600 ppm (13.2 μ mol CO2 m?2 s?1) and ambient control (8.3 μ mol CO2 m?2 s?1). This study showed that Frankia can improve growth, N fixation and photosynthesis of C. equietifolia rooted stem cuttings under extreme elevated CO2 level conditions (900 ppm). 相似文献
92.
Electrochemical Energy Storage with a Reversible Nonaqueous Room‐Temperature Aluminum–Sulfur Chemistry
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A reversible room‐temperature aluminum–sulfur (Al‐S) battery is demonstrated with a strategically designed cathode structure and an ionic liquid electrolyte. Discharge–charge mechanism of the Al‐S battery is proposed based on a sequence of electrochemical, microscopic, and spectroscopic analyses. The electrochemical process of the Al‐S battery involves the formation of a series of polysulfides and sulfide. The high‐order polysulfides (Sx2?, x ≥ 6) are soluble in the ionic liquid electrolyte. Electrochemical transitions between S62? and the insoluble low‐order polysulfides or sulfide (Sx 2?, 1 ≤ x < 6) are reversible. A single‐wall carbon nanotube coating applied to the battery separator helps alleviate the diffusion of the polysulfide species and reduces the polarization behavior of the Al‐S batteries. 相似文献
93.
Arumugam Dhanesh Gandhi Dhandapani Kayal Vizhi Kubendiran Lavanya V.N. Kalpana V. Devi Rajeswari Ranganathan Babujanarthanam 《Biochemistry and Biophysics Reports》2017
The main objective of this research is to investigate the anti-biofilm and anti-bacterial activity of Sesbania grandiflora (S. grandiflora) against Staphylococcus aureus. S. grandiflora extract were prepared and analyzed with UV –Vis spectroscopy, Fourier transform infrared spectroscopy, Dynamic light scattering. Biofilm forming pathogens were identified by congo-red assay. Quantification of Extracellular polymeric substance (EPS) particularly protein and carbohydrate were calculated. The efficacy of the herbal extract S. grandiflora and its inhibition against the pathogenic strain of S. aureus was also evaluated. The gradual decrease or disappearance of peaks reveals the reduction of protein and carbohydrate content in the EPS of S. aureus when treated with S. grandiflora. The antibacterial activity of S. grandiflora extract against the bacterial strain S. aureus showed that the extract were more active against the strain. To conclude, anti-biofilm and antibacterial efficacy of S. grandiflora plays a vital role over biofilm producing pathogens and act as a good source for controlling the microbial population. 相似文献
94.
Arumugam Geetha Panneerselvam Saranya Sam Annie Jeyachristy Rajagopal Surendran Arunachalam Sundaram 《Biological trace element research》2009,130(3):229-240
Altered copper homeostasis and oxidative stress have been observed in patients with hepatocellular carcinoma. Non-ceruloplasmin
copper, the free form, is a potent pro-oxidant than the protein bound copper. The aim of the present study was to evaluate
which form of copper can be correlated with the oxidative stress in the circulation and in the malignant liver tissues of
hepatocellular carcinoma patients. Hepatocellular carcinoma patients (grades II and III, n = 18) were enrolled in this study. Serum levels of total, free and bound copper, ceruloplasmin, iron, iron-binding capacity,
lipid peroxidation products, and enzymatic and non-enzymatic antioxidants were quantified in serum and in malignant liver
tissues and compared with those of normal samples (n = 20). A significant positive correlation between the serum non-ceruloplasmin copper and lipid peroxidation products and
negative correlation with antioxidants were observed in hepatocellular carcinoma patients. In liver tissue, glutathione peroxidase,
superoxide dismutase, and catalase activity were significantly decreased with concomitant elevation in oxidative stress markers.
Our experiment revealed that the elevation in non-ceruloplasmin copper has high relevance with the oxidative stress than the
bound copper. 相似文献
95.
A synthetic androgen 7α-Methyl-19-nortestosterone (MENT) has a potential for therapeutic use in ‘androgen replacement therapy’ for hypogonadal men or as a hormonal male-contraceptive in normal men. Its tissue distribution, excretion and metabolic enzyme(s) have not been reported. Therefore, the present study tested the distribution and excretion of MENT in Sprague-Dawley rats castrated 24 h prior to the injection of tritium-labeled MENT (3H-MENT). Rats were euthanized at different time intervals after dosing, and the amount of radioactivity in various tissues/organs was measured following combustion in a Packard oxidizer. The radioactivity (% injected dose) was highest in the duodenal contents in the first 30 min of injection. Specific uptake of the steroid was observed in target tissues such as ventral prostate and seminal vesicles at 6 h, while in other tissues radioactivity equilibrated with blood. Liver and duodenum maintained high radioactivity throughout, as these organs were actively involved in the metabolism and excretion of most drugs. The excretion of 3H-MENT was investigated after subcutaneous injection of 3H-MENT into male rats housed in metabolic cages. Urine and feces were collected at different time intervals (up to 72 h) following injection. Results showed that the radioactivity was excreted via feces and urine in equal amounts by 30 h.Aiming to identify enzyme(s) involved in the MENT metabolism, we performed in vitro metabolism of 3H-MENT using rat and human liver microsomes, cytosol and recombinant cytochrome P450 (CYP) isozymes. The metabolites were separated by thin-layer chromatography (TLC). Three putative metabolites (in accordance with the report of Agarwal and Monder [Agarwal AK, Monder C. In vitro metabolism of 7α-methyl-19-nortestosterone by rat liver, prostate, and epididymis. Endocrinology 1988;123:2187-93]), [i] 3-hydroxylated MENT by both rat and human liver cytosol; [ii] 16α-hydroxylated MENT (a polar metabolite) by both rat and human hepatic microsomes; and [iii] 7α-methyl-19-norandrostenedione (a non-polar metabolite) by human hepatic microsomes, were obtained. By employing chemical inhibitors and specific anti-CYP antibodies, 3H-MENT was found to be metabolized specifically by rat CYP 2C11 and 3-hydroxysteroid dehydrogenase (3-HSD) enzymes whereas in humans it was accomplished by CYP 3A4, 17β-hydroxysteroid dehydrogenase (17β-HSD) and 3-HSD enzymes. 相似文献
96.
97.
98.
Vijaya Ramachandran Thiruvengadam Arumugam Robert Langley Rosa F. Hwang Pablo Vivas-Mejia Anil K. Sood Gabriel Lopez-Berestein Craig D. Logsdon 《PloS one》2009,4(10)
Background
Adrenomedullin (AM) is highly expressed in pancreatic cancer and stimulates pancreatic cancer cells leading to increased tumor growth and metastasis. The current study examines the role of specific AM receptors on tumor and cells resembling the tumor microenvironment (human pancreatic stellate - HPSC, human umbilical vein – HUVEC and mouse lung endothelial cells - MLEC).Methods and Findings
AM receptors ADMR and CRLR were present in HPSC, HUVEC and MLECs while PDAC cells possessed only ADMR receptors as assessed by RT-PCR and western blotting. All cell lines expressed and secreted AM as indicated by ELISA. The growth of each of the cell lines was stimulated by exogenous AM and inhibited by the antagonist AMA. AM also stimulated in vitro angiogenesis assessed by polygon formation of endothelial cell lines. SiRNA-mediated silencing of ADMR, but not CRLR, reduced basal growth of all cells examined and reduced polygon formation of endothelial cells in vitro. Orthotopic tumors developed with shADMR bearing cancer cells had dramatically reduced primary tumor volume (>90%) and lung and liver metastasis compared to shControl bearing cells. To validate ADMR as a potential therapeutic target, in vivo studies were conducted using neutral nanoliposomes to systemically deliver human siRNA to ADMR to silence human cancer cells and mouse siRNA to ADMR to silence mouse tumor stromal cells. Systemic silencing of both human and mouse ADMR had no obvious adverse effects but strongly reduced tumor development.Conclusion
ADMR mediates the stimulatory effects of AM on cancer cells and on endothelial and stellate cells within the tumor microenvironment. These data support the further development of ADMR as a useful target treatment of pancreatic cancer. 相似文献99.
100.
Bhattacharyya A Thakur AK Chellgren VM Thiagarajan G Williams AD Chellgren BW Creamer TP Wetzel R 《Journal of molecular biology》2006,355(3):524-535
There are nine known expanded CAG repeat neurological diseases, including Huntington's disease (HD), each involving the repeat expansion of polyglutamine (polyGln) in a different protein. Similar conditions can be induced in animal models by expression of the polyGln sequence alone or in other protein contexts. Besides the polyGln sequence, the cellular context of the disease protein, and the sequence context of the polyGln within the disease protein, are both likely to contribute to polyGln physical behavior and to pathology. In HD, the N-terminal, exon-1 segment of the protein huntingtin contains the polyGln sequence immediately followed by an oligoproline region. We show here that introduction of a P10 sequence C-terminal to polyGln in synthetic peptides decreases both the rate of formation and the apparent stability of the amyloid-like aggregates associated with this family of diseases. The sequence can be trimmed to P6 without altering the suppression, but a P3 sequence is ineffective. Spacers up to at least three amino acid residues in length can be inserted between polyGln and P10 without altering this effect. There is no suppression, however, when the P10 sequence is either placed on the N-terminal side of polyGln or attached to polyGln via a side-chain tether. The nucleation mechanism of a Q40 sequence is unchanged upon addition of a P10 C-terminal extension, yielding a critical nucleus of one. The effects of oligoPro length and structural context on polyGln aggregation are correlated strongly with alterations in the circular dichroism spectra of the monomeric peptides. For example, the P10 sequence eliminates the small amount of alpha helical content otherwise exhibited by the Q40 sequence. The P10 sequence may suppress aggregation by stabilizing an aggregation-incompetent conformation of the monomer. The effect is transportable: a P10 sequence fixed to the C terminus of the sequence Abeta similarly modulates amyloid fibril formation. 相似文献