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71.
Interfacial Engineering of P3HT/ZnO Hybrid Solar Cells Using Phthalocyanines: A Joint Theoretical and Experimental Investigation 下载免费PDF全文
Giuseppe Mattioli Sadok Ben Dkhil Maria Ilenia Saba Giuliano Malloci Claudio Melis Paola Alippi Francesco Filippone Paolo Giannozzi Anil Kumar Thakur Meriem Gaceur Olivier Margeat Abdou Karim Diallo Christine Videlot‐Ackermann Jörg Ackermann Aldo Amore Bonapasta Alessandro Mattoni 《Liver Transplantation》2014,4(12)
Atomistic simulations and experimental investigations are combined to study heterojunction interfaces of hybrid polymer solar cells, with the aim to better understand and precisely predict their photovoltaic properties. The focus is on a hybrid ternary model system based on a poly(3‐hexylthiophene) (P3HT)/zinc phthalocyanine (ZnPc)/ZnO interface, in which a ZnPc interlayer is applied to improve the performance of the hybrid interface. Theoretical predictions of the ternary system are validated against the properties of a concrete P3HT/ZnPc/ZnO planar heterojunction device. The theoretical predictions closely agree with the photovoltaic properties obtained in P3HT/ZnPc/ZnO solar cells, indicating the strength of the method for modeling hybrid heterojunction interfaces. The theoretical and experimental results reveal that: i) ZnPc molecules in direct contact with a ZnO surface insert new energy levels due to a strong ZnPc/ZnO coupling, ii) electron injection from these new energy levels of ZnPc into ZnO is highly efficient, iii) the ZnPc/ZnO coupling strongly influences the energy levels of the ZnO and P3HT leading to a reduction of the open circuit voltage, and iv) charge carrier recombination at the P3HT/ZnO interface is reduced by the ZnPc interlayer. The intercalation of ZnPc leads to an increase in photocurrent as well as to an overall increase in power conversion. 相似文献
72.
Chen IY Lypowy J Pain J Sayed D Grinberg S Alcendor RR Sadoshima J Abdellatif M 《The Journal of biological chemistry》2006,281(28):19369-19377
In this study we have shown that the histone variant H2A.z is up-regulated during cardiac hypertrophy. Upon its knock-down with RNA interference, hypertrophy and the underlying increase in growth-related genes, protein synthesis, and cell size were down-regulated. During attempts to understand the mode of regulation of H2A.z, we found that overexpression of silent information regulator 2alpha (Sir2alpha) specifically induced down-regulation of H2A.z via NAD-dependent activity. This effect was reversed by the proteasome inhibitor epoxomicin, suggesting a Sir2alpha-mediated ubiquitin/proteasome-dependent mechanism for degradation of H2A.z. An increase in Sir2alpha also resulted in a dose-dependent reduction of the response to hypertrophic stimuli, whereas its inhibition resulted in enhanced hypertrophy and apoptosis. We have shown that Sir2alpha directly deacetylates H2A.z. Mutagenesis proved that lysines 4, 7, 11, and 13 do not play a role in the stability of H2A.z, whereas Lys-15 was indispensable. Meanwhile, Lys-115 and conserved, ubiquitinatable Lys-121 are critical for Sir2alpha-mediated degradation. Fusion of the C terminus of H2A.z (amino acids 115-127) to H2A.x or green fluorescence protein conferred Sir2alpha-inducible degradation to the former protein only. Because H2A.x and H2A.z have conserved N-tails, this implied that both the C and N termini are critical for mediating the effect of Sir2alpha. In short, the results suggest that H2A.z is required for cardiac hypertrophy, where its stability and the extent of cell growth and apoptosis are moderated by Sir2alpha. We also propose that Sir2alpha is involved in deacetylation of H2A.z, which results in ubiquitination of Lys-115 and Lys-121 and its degradation via a ubiquitin/proteasome-dependent pathway. 相似文献
73.
Salicylic acid alleviates mercury toxicity by preventing oxidative stress in roots of Medicago sativa 总被引:1,自引:0,他引:1
Zhao Sheng Zhou Kai Guo Abdelrahman Abdou Elbaz Zhi Min Yang 《Environmental and Experimental Botany》2009,65(1):27-34
Salicylic acid (SA) as a signal molecule mediates many biotic and environmental stress-induced physiological responses in plants. In this study, we investigated the role of SA in regulating Hg-induced oxidative stress in the roots of alfalfa (Medicago sativa). Plants pretreated with 0.2 mM SA for 12 h and subsequently exposed to 10 μM Hg2+ for 24 h displayed attenuated toxicity to the root. The SA-promoted root growth was correlated with decreased lipid peroxidation in root cells. The ameliorating effect of SA was confirmed by the histochemical staining for the detection of loss of membrane integrity in Hg-treated roots. We show that treatment with 0.2 mM SA increased the activity of NADH oxidase, ascorbate peroxidase (APX) and peroxidase (POD) in the roots exposed Hg. However, a slightly decreased superoxide dismutase (SOD) activity was observed in SA + Hg-treated roots when compared to those of Hg treatment alone. We also measured accumulation of ascorbate (ASC), glutathione (GSH) and proline in the roots of alfalfa and found that roots treated with SA in the presence of Hg accumulated more ASC, GSH and proline than those treated with Hg only. These results suggest that exogenous SA may improve the tolerance of the plant to the Hg toxicity. 相似文献
74.
75.
Auffray C Gayon R Benraiss A Martin N Laurendeau I Garaud J Lucas B Boitard C Krief P 《Experimental cell research》2006,312(3):233-244
Notch signaling participates in the development of multicellular organisms by maintaining self-renewal potential or inducing differentiation of numerous tissues. In this study, we characterized Notch4, the evolutionary most distant and least studied Notch family member. We identified a Notch4 inter-strain polymorphism with a previously undescribed mRNA variant. This longer Notch4 mRNA, which represented up to one-third of total Notch4 mRNA, resulted from intron 10 retention. Analysis of Notch4 intron 10 revealed that an 8-bp deletion, reducing its length from 68 to 60 bp, strictly correlated with its retention. Further experiments demonstrated that intron length was the only cause of the mis-splicing. Moreover, this mRNA variant resulted in a truncated protein containing half the extracellular domain of Notch4, including the ligand-binding domain. 相似文献
76.
Amza A Goldschmidt P Einterz E Huguet P Olmiere C Bensaid P Bella-Assumpta L 《PLoS neglected tropical diseases》2010,4(11):e895
Background
Following an epidemiological study carried out in 2006 showing a high prevalence of blinding trachoma in the Far North Region of Cameroon, a trachoma elimination programme using the SAFE strategy was initiated: three yearly trachoma mass treatments were to be performed.Methodology/Principal Findings
The entire district population (120,000 persons) was treated with azithromycin 1.5% eye drops in February 2008 and January 2009. To assess the effect of treatment on the prevalence of active trachoma, three epidemiological studies were conducted on a representative sample of children aged between 1 and 10 years. The first study was performed just prior to the first treatment, the second just prior to the 2nd treatment and the third one, one year later. The prevalence of active forms of trachoma (TF + TI) dropped from 31.5% (95%CI 26.4–37.5) before treatment to 6.3% (95%CI 4.1–9.6) one year after first treatment; a reduction of nearly 80%. One year after the second treatment, the prevalence decreased to 3.1% (95%CI 2.0–4.9), a total reduction of 90%. Furthermore, there were no more TI cases (only TF). There was no report of serious or systemic side effects. Tolerance was excellent.Conclusions/Significance
Active trachoma mass treatment with azithromycin 1.5% eye drops is feasible, well tolerated, and effective. 相似文献77.
Abdou Tchoukoua Narandulam Usukhbayar Ken-ichi Kimura Eunsang Kwon Hiroyuki Momma 《Bioscience, biotechnology, and biochemistry》2017,81(12):2261-2267
Four new oleanane-type saponins, macrostachyaosides A, B, C, and D (1–4) were isolated from the roots of Acacia macrostachya. Their structures were elucidated on the basis of extensive 1D- and 2D-NMR data and HR-ESI-MS analyses. At concentrations of 100 μM of each compounds, none of the tested compounds caused a significant growth reduction against HL60 cells. 相似文献
78.
Lobna Abdellatif Sadok Bouzid Susan Kaminskyj Vladimir Vujanovic 《Mycological Research》2009,113(6-7):782-791
Root endophytic fungi are seen as promising alternatives to replace chemical fertilizers and pesticides in sustainable and organic agriculture systems. Fungal endophytes structure formations play key roles in symbiotic intracellular association with plant-roots. To compare the morphologies of Ascomycete endophytic fungi in wheat, we analyzed growth morphologies during endophytic development of hyphae within the cortex of living vs. dead root cells. Confocal laser scanning microscopy (CLSM) was used to characterize fungal cell morphology within lactofuchsin-stained roots. Cell form regularity Ireg and cell growth direction Idir, indexes were used to quantify changes in fungal morphology. Endophyte fungi in living roots had a variable Ireg and Idir values, low colonization abundance and patchy colonization patterns, whereas the same endophyte species in dead (γ-irradiated) roots had consistent form of cells and mostly grew parallel to the root axis. Knot, coil and vesicle structures dominated in living roots, as putative symbiotic functional organs. Finally, an increased hypha septation in living roots might indicate local specialization within endophytic Ascomycota. Our results suggested that the applied method could be expanded to other septate fungal symbionts (e.g. Basidiomycota). The latter is discussed in light of our results and other recent discoveries. 相似文献
79.
Amza A Kadri B Nassirou B Stoller NE Yu SN Zhou Z Chin S West SK Bailey RL Mabey DC Keenan JD Porco TC Lietman TM Gaynor BD;PRET Partnership 《PLoS neglected tropical diseases》2012,6(4):e1586
Background
Trachoma control programs utilize mass azithromycin distributions to treat ocular Chlamydia trachomatis as part of an effort to eliminate this disease world-wide. But it remains unclear what the community-level risk factors are for infection.Methods
This cluster-randomized, controlled trial entered 48 randomly selected communities in a 2×2 factorial design evaluating the effect of different treatment frequencies and treatment coverage levels. A pretreatment census and examination established the prevalence of risk factors for clinical trachoma and ocular chlamydia infection including years of education of household head, distance to primary water source, presence of household latrine, and facial cleanliness (ocular discharge, nasal discharge, and presence of facial flies). Univariate and multivariate associations were tested using linear regression and Bayes model averaging.Findings
There were a total of 24,536 participants (4,484 children aged 0–5 years) in 6,235 households in the study. Before treatment in May to July 2010, the community-level prevalence of active trachoma (TF or TI utilizing the World Health Organization [WHO] grading system) was 26.0% (95% CI: 21.9% to 30.0%) and the mean community-level prevalence of chlamydia infection by Amplicor PCR was 20.7% (95% CI: 16.5% to 24.9%) in children aged 0–5 years. Univariate analysis showed that nasal discharge (0.29, 95% CI: 0.04 to 0.54; P = 0.03), presence of flies on the face (0.40, 95% CI: 0.17 to 0.64; P = 0.001), and years of formal education completed by the head of household (0.07, 95% CI: 0.07 to 0.13; P = 0.03) were independent risk factors for chlamydia infection. In multivariate analysis, facial flies (0.26, 95% CI: 0.02 to 0.49; P = 0.03) and years of formal education completed by the head of household (0.06, 95% CI: 0.008 to 0.11; P = 0.02) were associated risk factors for ocular chlamydial infection.Interpretation
We have found that the presence of facial flies and years of education of the head of the household are risk factors for chlamydia infection when the analysis is done at the community level.Trial Registration
ClinicalTrials.gov NCT00792922相似文献80.
RasGAP (Ras GTPase-activating protein) is a negative regulator as well as a downstream effector of Ras. To identify partners of RasGAP we used it as the bait in a yeast two-hybrid screen. This resulted in discovering its interaction with Akt. Overexpression of RasGAP or a mutant lacking the GTPase-activating domain (nGAP) enhanced phosphorylation and activity of Akt, which was dependent on the upstream integrin-linked kinase. Also, nGAP protected the cells against staurosporin-induced apoptosis through an Akt-dependent pathway. To determine the role of RasGAP in receptor-mediated activation of Akt, we used short hairpin RNA interference to knock out endogenous RasGAP expression. Although this procedure resulted in enhanced Ras activity, it inhibited Akt phosphorylation. Thus, we propose that Ras-GAP interacts with Akt and is necessary for its activation, possibly via integrin-linked kinase-mediated phosphorylation of Ser-473. The data suggest that this effect is independent of Ras activity. 相似文献