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Panayotis Dimopoulos Karle V. Sýkora Ladislav Mucina Theodoros Georgiadis 《Folia Geobotanica》1997,32(3):313-334
A revision was undertaken of the high-rank syntaxa of the vegetation occurring in rock fissures, ledges and screes of mainland Greece and Crete. All published phytosociological relevés available were collected and subjected to numerical classification and ordination. Four orders (Androsacetalia vandelii, Onosmetalia frutescentis, Potentilletalia speciosae andPetromaruletalia pinnatae) comprising 8 alliances (one of them new) were distinguished within theAsplenietea trichomanis (rock fissures, clefts, and ledges). The scree vegetation was classified partly within theThlaspietea rotundifolii (Drypidetalia spinosae with 2 alliances) and partly within theDaphno-Festucetea (Saturejo-Scutellarietalia—a new order, with 2 alliances). Ordination revealed clear differences in floristic composition of the alliances distinguished. The studied chasmophytic vegetation of Greece contains a very high proportion of endemics which serve as diagnostic species of the syntaxa. Further, an analysis of chorological species spectra suggested that the chorological homogeneity of a syntaxon should be considered an important diagnostic feature at high-syntaxon levels. 相似文献
44.
Sophie A. Lee Theodoros Economou Rafael de Castro Cato Christovam Barcellos Rachel Lowe 《PLoS neglected tropical diseases》2021,15(12)
Dengue is hyperendemic in Brazil, with outbreaks affecting all regions. Previous studies identified geographical barriers to dengue transmission in Brazil, beyond which certain areas, such as South Brazil and the Amazon rainforest, were relatively protected from outbreaks. Recent data shows these barriers are being eroded. In this study, we explore the drivers of this expansion and identify the current limits to the dengue transmission zone. We used a spatio-temporal additive model to explore the associations between dengue outbreaks and temperature suitability, urbanisation, and connectivity to the Brazilian urban network. The model was applied to a binary outbreak indicator, assuming the official threshold value of 300 cases per 100,000 residents, for Brazil’s municipalities between 2001 and 2020. We found a nonlinear relationship between higher levels of connectivity to the Brazilian urban network and the odds of an outbreak, with lower odds in metropoles compared to regional capitals. The number of months per year with suitable temperature conditions for Aedes mosquitoes was positively associated with the dengue outbreak occurrence. Temperature suitability explained most interannual and spatial variation in South Brazil, confirming this geographical barrier is influenced by lower seasonal temperatures. Municipalities that had experienced an outbreak previously had double the odds of subsequent outbreaks. We identified geographical barriers to dengue transmission in South Brazil, western Amazon, and along the northern coast of Brazil. Although a southern barrier still exists, it has shifted south, and the Amazon no longer has a clear boundary. Few areas of Brazil remain protected from dengue outbreaks. Communities living on the edge of previous barriers are particularly susceptible to future outbreaks as they lack immunity. Control strategies should target regions at risk of future outbreaks as well as those currently within the dengue transmission zone. 相似文献
45.
Evangelia E. Tsakiridis Lindsay Broadfield Katarina Marcinko Olga-Demetra Biziotis Amr Ali Bassem Mekhaeil Elham Ahmadi Kanwaldeep Singh Aruz Mesci Panayiotis G. Zacharidis Alexander E. Anagnostopoulos Tobias Berg Paola Muti Gregory R. Steinberg Theodoros Tsakiridis 《Translational oncology》2021,14(11):101209
BackgroundThere is need for well-tolerated therapies for prostate cancer (PrCa) secondary prevention and to improve response to radiotherapy (RT). The anti-diabetic agent metformin (MET) and the aspirin metabolite salicylate (SAL) are shown to activate AMP-activated protein kinase (AMPK), suppress de novo lipogenesis (DNL), the mammalian target of rapamycin (mTOR) pathway and reduce PrCa proliferation in-vitro. The purpose of this study was to examine whether combined MET+SAL treatment could provide enhanced PrCa tumor suppression and improve response to RT.MethodsAndrogen-sensitive (22RV1) and resistant (PC3, DU-145) PrCa cells and PC3 xenografts were used to examine whether combined treatment with MET+SAL can provide improved anti-tumor activity compared to each agent alone in non-irradiated and irradiated PrCa cells and tumors. Mechanisms of action were investigated with analysis of signaling events, mitochondria respiration and DNL activity assays.ResultsWe observed that PrCa cells are resistant to clinically relevant doses of MET. Combined MET + SAL treatment provides synergistic anti-proliferative activity at clinically relevant doses and enhances the anti-proliferative effects of RT. This was associated with suppression of oxygen consumption rate (OCR), activation of AMPK, suppression of acetyl-CoA carboxylase (ACC)-DNL and mTOR-p70s6k/4EBP1 and HIF1α pathways. MET + SAL reduced tumor growth in non-irradiated tumors and enhanced the effects of RT.ConclusionMET+SAL treatment suppresses PrCa cell proliferation and tumor growth and enhances responses to RT at clinically relevant doses. Since MET and SAL are safe, widely-used and inexpensive agents, these data support the investigation of MET+SAL in PrCa clinical trials alone and in combination with RT. 相似文献
46.
Tassou CC Panagou EZ Samaras FJ Galiatsatou P Mallidis CG 《Journal of applied microbiology》2008,104(6):1764-1773
Aims: The purpose of this study was to investigate the inactivation kinetics of Staphylococcus aureus in a ham model system by high hydrostatic pressure at ambient (25°C) and selected temperatures (45, 55°C). Selective [Baird Parker (BP) agar] and nonselective [brain heart infusion (BHI) agar] growth media were used for enumeration in order to count viable and sublethally injured cells. Methods and Results: The micro‐organism was exposed to a range of pressures (450, 500, 550, 600 MPa) at ambient temperature (25°C) for up to 45 min. Additionally, the behaviour of the micro‐organism was evaluated at mild temperatures in combination with high pressure treatment, namely: (i) 350, 400 and 450 MPa at 45°C; and (ii) 350 and 400 MPa at 55°C, for up to 12 min. Inactivation kinetics were calculated in terms of Dp and zp values. Survival curves of S. aureus at ambient temperature were mostly linear, whereas when temperature was applied, tailing was observed in most survival curves. The estimated Dp values and therefore the number of surviving cells, were substantially higher on the selective BP agar in the whole range of pressures applied, indicating that S. aureus showed greater recovery in the selective BP agar than the nonselective BHI agar. Samples pressurized at ambient temperature needed higher pressures (over 500 MPa) to achieve a reduction of the population of the pathogen more than 5 log CFU ml?1. The same level of inactivation was achieved at lower pressure levels when mild heating was simultaneously applied. Indeed, more than 6 log CFU ml?1 reductions were obtained at 400 MPa and 55°C within the first 7 min of the process in BHI medium. Conclusion: Elevated temperatures allowed lower pressure levels and shorter processing times of pathogen inactivation than at room temperature. Greater recovery of the pathogen was observed in the selective (BP agar) medium, regardless of pressure and temperature applied. Significance and Impact of the Study: The obtained kinetics could be employed by the industry in selecting optimum pressure/temperature processing conditions. Attention must be given to the selection of the enumeration medium, as the use of an inappropriate medium would lead to underestimation of the surviving cells, thus imposing a risk in the microbiological safety of the product. 相似文献
47.
Theodoros Goulas Athanasios Goulas George Tzortzis Glenn R. Gibson 《Applied microbiology and biotechnology》2009,82(3):471-477
A genomic library of Bifidobacterium bifidum (NCIMB 41171) DNA was constructed in Escherichia coli RA11r (melA−B+) and one α-galactosidase encoding gene was isolated. Conceptual translation combined with insertional mutagenesis analysis
indicated an open reading frame (ORF) of 759 amino acid (aa) residues encoding an α-galactosidase (named as MelA) of 82.8 kDa.
Partial purification and characterisation showed that the enzyme had an apparent native molecular mass of ≈243 kDa and a subunit
size of ≈85 kDa. The enzyme belongs to glycosyl hydrolases 36 family with high aa sequence similarities (≈73%) to other known
α-galactosidases of bifidobacterial origin. Under optimum pH conditions for activity (pH 6.0) and high melibiose concentration
(40% w/v), the enzyme was able to form oligosaccharides with degree of polymerisation (DP) ≥3 at higher concentration than DP = 2,
with a total yield of 20.5% (w/w). 相似文献
48.
The Arabidopsis Abscisic Acid Catabolic Gene CYP707A2 Plays a Key Role in Nitrate Control of Seed Dormancy 下载免费PDF全文
49.
Nadine S. Taylor Ralf J. M. Weber Andrew D. Southam Tristan G. Payne Olga Hrydziuszko Theodoros N. Arvanitis Mark R. Viant 《Metabolomics : Official journal of the Metabolomic Society》2009,5(1):44-58
Currently there is a surge of interest in exploiting toxicogenomics to screen the toxicity of chemicals, enabling rapid and
accurate categorisation into classes of defined mode-of-action (MOA), and prioritising chemicals for further testing. Direct
infusion FT-ICR mass spectrometry-based metabolomics can provide a sensitive and unbiased analysis of metabolites in only
15 mins and therefore has considerable potential for chemical screening. The water flea, Daphnia magna, is an OECD test species and is utilised internationally for toxicity testing. However, no metabolomics studies of this species
have been reported. Here we optimised and evaluated the effectiveness of FT-ICR mass spectrometry metabolomics for toxicity
testing in D. magna. We confirmed that high-quality mass spectra can be recorded from as few as 30 neonates (<24 h old; 224 μg dry mass) or a
single adult daphnid (301 μg dry mass). An OECD 24 h acute toxicity test was conducted with neonates at copper concentrations
of 0, 5, 10, 25, 50 μg l−1. A total of 5447 unique peaks were detected reproducibly, of which 4768 were assigned at least one empirical formula and
1017 were putatively identified based upon accurate mass measurements. Significant copper-induced changes to the daphnid metabolome,
consistent with the documented MOA of copper, were detected thereby validating the approach. In addition, N-acetylspermidine was putatively identified as a novel biomarker of copper toxicity. Collectively, our results highlight the
excellent sensitivity, reproducibility and mass accuracy of FT-ICR mass spectrometry, and provide strong evidence for its
applicability to high-throughput screening of chemical toxicity in D. magna.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
50.
Vassilis Samaras Maria Tsopanomichalou Angeliki Stamatelli Christos Arnaoutoglou Efstathios Samaras Marianthi Arnaoutoglou Hercules Poulias Calypso Barbatis 《Diagnostic pathology》2009,4(1):1-9